Dealing with The House Damp - One Year in Our Humid Home
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- čas přidán 21. 07. 2024
- Our first year in our 'new to us' old stone home in France, where we are tackling moisture and mold issues as we renovate the property. From dehumidification, and simple actions to deal with the humidity in the day-to-day, to bigger solutions to secure a less moist future.
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00:00 - Intro
01:12 - In The Beginning
03:59 - Dehumidification and Other Approaches
06:00 - Monitoring Changes in Humidity
07:07 - Humidity & Temperature Data
10:00 - A Problem With The Data?
12:00 - Deeper Problems
17:00 - Deeper Solutions
17:56 - Interior Walls
20:17 - In Conclusion
Music:
Claude Patterns - Pattern 32
d0d - Orbit
Aaron Paul - Whispers In The Dark
Danijel Zambo - Shake It Off
Prigida - Continual
Claude Patterns - Pattern 32 (Reprise)
Ambient Boy - Violet Haze
Dominique Charpentier - Sur Le Fil
A lot of interesting comments here, especially regarding heating. We will eventually be installing a wood burner (approx 10 Kw) on the ground floor but have not yet settled on a way forward for the rest of the house. We would prefer not to use electric heaters if possible. So i'm adding heating to the 'research schedule'... in the meantime I'm always keen to read any ideas for stone home heating. Cheers.
10KW (34K BTU) seem incredibly small, especially for an older house that doesn't have proper insulation. The wood stove we have in our house is around double that and it's not even considered large, although it does get cold and snowy here in the winter. That said, wood stoves do have a way of drying out a house, a lot of people with them actually keep a large pot of water on the top to add moisture to the air.
If it's long term and you're going to be there when you're old consider how you're going to get wood, process it, how much it'll cost etc. Consider a wind or water turbine perhaps? That'll run in Winter when you need power the most. Electric heating is the way forward, unless wood is cheap, free and easy then wood burners are better as an option for cosy cold nights.
My sister had a wood burner 25 years ago before the became fashionable,and when they had it on it literally warmed the whole house up all they did was keep all the doors in the house open,then later at night shut the doors to keep the warmth in,don't know if this is any good but you can never have to much information good luck and I hope 2024 is a good year for you both 👍
I'd recommend you research 'rocket mass heaters' and masonry stoves. Designed correctly they burn FAR more efficiently than a standard wood burner, using FAR less fuel and producing FAR less particulate pollution. Much of the heat goes into a large thermal mass that gently radiates for hours after the fire has gone out. Whilst burning it'll suck all the moist air out of the house too. You can go full hippy and make it out of natural materials or build out of brick which can then be tiled or rendered for a smart finish. It's criminal how poorly conventional stoves perform.
@@beetooex But they are massive and appear to largely be a diy project. They are also ugly and you can't really see the fire when it's going.
Some of the challenges you are experiencing are also common in Norway, we love building houses with basements and it rains a lot here. Hence there is a national research institute that has done significant research on the optimal solutions in order to avoid humidity issues, these are now part of the building codes. In short summary: in the extent possible the landscape outside the house shall lean away from the building. Drainage shall be installed around the whole house and it shall sitt bellow the underside of the lowest floor of the building. Building walls bellow ground should be insulated on the outside in order to move the dewpoint to the outside of the wall, thus reducing the risk of water dew forming inside the wall. This will also add to the transport of water out of the walls. There shall be draining masses (gravel) around the walls, preferably with some sort of barrier to avoid it filling up with sediments clogging it. On the inside timber frames shall be freestanding and not connected to the walls by wood, minimum 30mm separation. Insulation on wallsections bellow ground shall be within the frame and also not in contact with the stone/concrete wall. Once above ground it can be insulated to the wall. I renovated a damp basement, it had mold, wet spots and salt renders, followed the recommendations to the book. It is bone dry and has really good environment, now five years in after restoration. It's a lot of work, but worth I in the long run. Good luck!
I agree, as a person living in cold nad rainy Poland 😉
Hello, do you have a link towards these building codes?
Watching this was like watching a video promoting why we have building standards and permits. I can’t help but think how many others live in these situations? It’s kind of scary.
There is a french dry lining system which fixes a stainless carcase to the inside of the wall to prevent bridging. With adequate ventilation of the cavity this is effective as it allows evaporation of 'normal' levels of water penetration of an external wall in good order with working gutters,
Insulating around the exterior of the basement must have been a major ($$$) job?
I have an old stone house in France. First thing I did was removed all concrete and plaster on the walls and replace with lime and sand. If I could do it again Inl would go for lime and hemp. But even now I always have a comfortable humidity level. Old houses and modern building materials = trouble.
Old houses are supposed to have free exchange with the environment to dry out. The chimneys with fires in them would constantly draw air through the house. The houses were not sealed. Technologies work as whole systems that's why mixing old and new only works if done very carefully and with complete understanding.
This is such an important point. You need to use lime plaster and renders on old houses like this, they weren't designed for modern impervious cements. If you crack off cement render you can often watch the damp mortar dry out within 30 minutes on a hot day. Same with insulation too, you'll want to use something like sheepwool, not modern plastic stuff. Peter Ward has lots of good videos on his CZcams channel about this.
"Old houses and modern building materials = trouble." Amen! Stick to old materials and old methods, and the house will work as intended. But do add modern knowledge about old houses, we have learned a thing or two since then. Just don't make the mistake of applying knowledge about modern houses to an old house.
Absolutely extend the roof when it will be replaced, at least 0.5m further than it is now, that will stop rain soaking the walls so much. Good luck with renovation.
You can check the calibration of your humidity sensors with a saturated salt water solution,a saucer and a plastic bag.
Dissolve as much table salt in water as you can. There should be some undissolved salt remaining. Pour the solution into a saucer and put in in a plastic bag or box with your sensors. The relative humidity should stabilize at 76% (0 to 15C) or 75% (20 to 40C). It's a nice easy check for the calibration.
Thank you!
This temperature is the problem 10 - 14⁰C is way to low, way to low. Even temperatures starting from 19⁰c down, creates areas in the house of higher humidity that is not able to be absorbed by the air. Beside all the other problems, get the temperature higher a least for some hours a day above 20⁰C. That will do wonders.
this right here!
I stopped the video at 9:00 when he was showing the temperature plot and was wtfing. So much effort into sensors while keeping the house at probably the most damp inducing temperature range. Of course he must from the UK, they love these inside temps 😅
That's easy to say, but in an old house like that it'll cost a fortune.
@@lksf9820 Yes you are right. But there is hardly any.other way. Heat is the main process to reduce moisture. Well all other things should be done. Walls must be dry etc... But heat is the main process.
@@christophmartin5381 After fixing the walls insulation is the next move, then it won't cost as much to heat.
The temperature must be maintained above the dew point (16-18°C); otherwise, humid outdoor air will condense inside the house most of the time.
1. Address direct water ingress through the roof and walls by fixing poor exterior pointing and/or improving the roof overhang.
2. Mortar, interior insulation and every paint must be vapor-permeable to allow water to escape from the wall. Use hygroscopic materials such as clay or lime, as these absorb and regulate relative humidity throughout the year. Avoid using cement, gypsum, or synthetic paints, as they are impermeable to water vapor; remove them from the interior walls.
3. For interior wall insulation, I recommend hemp-lime on the stone wall, plus a maximum of 6 cm wood-fiber insulation boards. Additionally, you could add a hydraulic wall heating system on the wood fiber board, finishing with another layer of lime.
4. Ensure proper ventilation or install a mechanical ventilation system with heat recovery.
5. Install a cheap split air-conditioning unit for heating and dehumidification
The dew point location is also affected by availability of heat (or 'cold') at the predicted thermal location.
It won't (can't) be inside an insulating block, rather it (the aggregate condensation) would be at one side or the other of the foam block and the thermal gradients adjust accordingly. (i.e. there's always extra complicating factors to consider ;-)
Exactly !!
For humid climate you must have ERV not HRV
I'd be using the chimney and fireplace to help draw away moisture. A fire helps a building to 'breathe'. Also, I'd strip away that cement and replace with hemp and lime....watching 'Make Do Grow' YT channel may help you with that. What a job you have taken on, wishing you both brilliant solutions and happy days. 🥰
Old style wood and coal stoves indeed immensely dry the interior - for example that's why we have the opposite problem at winter: below 20% RH is just low and that's just as bad as too high.
But these may not be legal in that area, and to be honest: they can be quite inconvenient too.
Many people in cities here made a compromise by installing electric heating into masonry stoves.
If the air circulation is not blocked then that's drying just as well.
The bill may be a 'bit' of a problem, though... But anyway, this is also a direction what might be considered.
Wood stove, it drougs out bad air and warms up, naturally. From where it takes in air, uppfrom where dryer, or not from down, it makes worse
Your walls are so beautiful! Point them with lime render, it removes carbon dioxide from the air and moisture will travel outside, point outside with lime as well! Keep to old methods, they have mostly stood the test of time❤
I'm in 1906 terrace in a valley by the coast (road outside is 7m above sea level). There was a lot of damp when i moved in, often over 70% RH.
A bit different as I have rendered brick walls. I've had scaffolding up front and rear to repaint the render, repair roof and gutters and cap 7 chimney pots. Ensure a 0.5-1% fall on the gutters to the drainpipes to ensure no standing water, helps move debris as well.
This all helped a lot but I've also installed a positive internal ventilation (PIV) unit. Basically a filtered fan which draws air from the loft into the hallway. It uses 3-4W so cheap to run. Set up for five air changes a day of the house volume. Pushes air into all the rooms and mostly vents up the chimney flues. Has improved indoor air quality as ensures constant ventilation as all windows changed to double glazed and the RH is always around high 50s low 60s now. Something to consider.
I have a 1921 semi with solid walls that was fitted with double glazing before we moved in , significant condensation/ high humidity has been a real problem - PIV fitted a week ago, no condensation, no need to run dehumidifier and RH down to high 50s, before we struggled to keep below 70! Cannot recommend enough!
We have a property that is 120 years old lime mortar throughout. Where I can the walls have dry lining on 5cm depth , rock wool insulation. We have kept the chimneys open. Each double glazed window has a vent as do the French doors. I’ve insulated all the gaps between ceiling and floor above using rook wool and leaving an air gap every where. There is definite air flow behind the walls with dry lining and the insulated floor. We also painted the house with a breathable brick cream. We do get little spots of damp in places but really not much.oh and I used fermacell boards not plaster boards on all those interior walls that were outside walls. Not that they are water proof. Good luck
Brilliant filming, I live in a similar property in Germany and as a “layperson” you put across more clearly than “experts” the problems in juggling the many issues. All I can say is good luck and best wishes.
We have an old house in Brittany, purchased some years ago, built partially into the ground at the back which is @1.5 metres higher than the front. We were concerned with potential damp. Our British builder recommended what seems to have been your previous owners solution, creating a barrier and then installing insulated plasterboard. There’s obviously no damp proof course. Our French builder said in effect ‘we let the water in and then we let it out again’. The house is built with local stone which is a little porous with lime mortar between stones. The walls are of traditional construction around three feet thick with an inner and outer stone skin infilled with earth. We have an internal lime plaster. We insulated inside the tiled roof leaving an air gap but did nothing with the walls. The windows are traditional single glazed units with, we discovered, ventilation built in. Our main heating is a wood burning stove, backed up with electric heaters which we rarely use. The stove is big enough to keep us warn without roasting. We have found the local builder to be correct. We have left our house for the winter without visiting on several occasions without any heating. Whilst mice have been an occasional problem the damp never has. The house takes a day or two to air but is perfectly liveable in on our return. Our next door neighbours property is part of the same building but they have tremendous damp issues because they have used cement mortar. It makes a big difference! Good luck with your ongoing works. I have found everything is a learning curve but if you work with nature and pay attention to natural time honoured methods, adapting them when needed you stand some chance. Just as an aside Roger Barnes @RovingRoger is renovating a house in Brittany with similar (but less acute) problems as yours and has decided on a hemp lime solution for the interior. You might find his videos interesting.
I said this a year ago and I think it still merits doing. Parallel with the back of the house starting behind your well /sump, dig another deep french drain system to carry off water draining down your back slope, emptying to the street. That way your draining more rainwater before it hits the homes new damp course. Easier would be to grade the back of the house to create a natural valley in your back yard that runs again to the street. I know the slope you have is steep and regrading everything away from the foundations would make your back yard difficult to walk around in but it seems to me you have an actual natural spring running thru your homes foundation. I know you did the damp course already and it was a huge job but you may need two parallel drainage systems to divert that spring. Been subscribed since your first video and I hope I'm not offending you it's just my thought and sent with care.❣️
Hard agree. Having 'been there, done that' ten years ago, I'd recommend paying heed to these suggestions in the comments. You do have to wage war against water. As any farmer will tell you - Water will always find a way. I am not surprised that the internal humidity is unchanged. I also wonder if this building was originally converted from agricultural to residential in a previous century..
Just a suggestion for your insulation, I would remove the cement layer everywhere I can and replace it with lime, it works very well to regulate humidity.
Then I would install partition walls with an air gap of 5-10cm from the structural walls, possibly with some vents to let air circulate in this air gap. This would help the humidity absorbed by lime to evacuate somewhere.
For the partition walls I mentioned, I would use breathing and water resistant materials : recycled cotton or cork for insulation, Fermacell for boards. Mounted on galvanized rails that are the way everyone is doing in France (we call it "rails placo" there's a whole ecosystem of accessories and techniques for it). The insulation and Fermacell boards will be pricey though but it's much better than the usual fiberglass and plasterboards and should help to save your investment.
I know some people when building log cabins, say to use lime mortar as it breathes and is easy to patch and keeps from storing moisture and hurting the space between the logs.
@@kfl611 yes actually the traditional way to build houses and barns in france was stones held with lime mortar. But in some houses they redid de mortar with cement in the 70s or 80s and created a lot of problems
I try to work with lime mortar and plasters longer slower process but it works and your not leaving a problem for the next generation like the incorrect use of cement products have
Old houses like yours didn't have damp coases. But didn't really get damp unless there was a problem. What helped a lot with keeping the houses dry then was open fires in the house. Say if you put an open fire or stove back in your house. Even if you only have it in during the work. It could help you to dry out your house. A place for all the wood off-cuts you will have during the work you will be doing
This is the first stage, you need some heat because and dehumidification requires the moisture to be in the air to be "transported" away.
I have said on many other similar videos raising the temperature and ventilating for 3 to 4 minutes on cold breezy days as often as the humidity builds up again, will remove vast amounts of moisture without the loss of energy because the structure of the building need to warm but not be cooled by the ventilation. This could be done every hour or even 30minutes to start with.
Long term after the removal of the bodged remedial work the installation of an MVHR would automate this venting and redistribute the heat from for example a wood burner throughout the house.
Good luck, subscribed.
@@ooslum In my place the walls wouldn't dry out. I was told by a builder to install a stove and it did exactly as he said. He said a fire pulls the moisture out of the walls. My dehumidifiers needed emptying more often. My dad's House never needed a damp course while he had a stove. No soon as he took the stove out. The damp was breaking out everywhere. Until he refitted a stove
@@jonstorey6414 The stone in those wall is unlikely to absorb water it is usually the surrounding "adhesive" that does that. Walls can do this but is normally the likes of sandstone.
You would get the moisture moving towards the drier, warmer parts of the building as you say but if the building is starved of the supply it will dry out even if that is not how it appears at first. I used to hired out dehumidifiers and have endless complaints from people running them in unheated conditions, they simply provide an alternative cold surface for the moisture to condense on but first the moisture must be air-bound, a dehumidifier would struggle to compete with a stone wall and absorbant mortar at less than 10°c.
Your suggestion of heat is the correct first approach but this will seem to make the air in the house initially wetter because it's rise in humidity. Cadence ventilation will remove the now moisture laden air without cooling the building, the thermal mass of the air is minute in comparison to the building and the humidity will quickly rise as soon as the ventilation is stopped, this is why I suggested an MVHR.
I think if I were in this position I would also consider a veranda around the building, this is effectively what the neighbours have done with their extentions. I think you can live with many problems but damp is not one of them, cheers.
Perhaps like a pellet stove, with an auto-feed hopper. I bet that would help heat things up and dry out your air, and provide some nice heat too. I know some pellet stoves are supposed to be very environmentally friendly - they produce only a little ash and almost no smoke, so you will not be contributing too much to global warming - and more moisture in the air (as the polar regions melt).
MVHR (Mechanical Ventilation with Heat Recovery) for those unfamiliar with the particular term (I had to google it) @@ooslum
Whatever the issues you face with the house, never forget how lucky you are to get such a beautiful and always smiling woman. Pour le reste, courage !
I bought an old cottage built in 1900. I stumbled across similar problems and solutions like yourself. Stones walls being able to breathe made the biggest difference so far for me. Replacing the cement plaster and repointing with lime mortar. Ventilation is need too. Your definitely on the right path to a dry comfortable home.
You are approaching this with such wonderful logic and respect. I have lived in all sorts of houses including a canvas tipi, a Croft house made of granite, a 1960’s semi, a prefab apartment etc. The tipi taught me that every kind of house is just a shelter. You cannot shut out the cold and damp entirely and ventilation is the key. Old houses worked because they had chimneys drawing out warm damp air day and night, and they had drafty windows and doors and people wore wool not cotton tea shirts. An entirely different way of living. Polystyrene and plasterboard what a horrible combination! I think you have the right mindset and will discover the best balance eventually although the flow of air might need be higher than is fashionable. Good luck I will be watching
I'm late to this video but wanted to make a suggestions I couldn't find in the comments: If you're replacing the roof anyway, consider changing the pitch enough that you're able to extend the roof further in front of the walls. Also consider extending the roof a meter or so beyond the side wall. You're doing so much work to keep damp from climbing up the stone foundation that it would also be positive to keep water from hitting the walls as much as possible. You'll never get it all, but a properly sized roof will make a difference in how much moisture you need to deal with.
I really like your style and approach and firmly believe you are on the right track.
Improving the ground drainage is a massive step, the new roof and guttering are massive steps too.
However, following those massive steps requires three things, (1) Ventilation, (2) Heating (3) Time and in this case that time may well be a year. If you have working and patent chimneys (I cannot remember seeing fireplaces) but if that is the case you should retain them at least until you are satisfied you have got the property dried out as they do contribute to ventilation. I know it is not a particularly eco approach but a modern 8KW log burner may be worth considering as an effort to affordabley maintain the house at more consistent and higher temperatures to drive the moisture out.
When your home was originally built it was a drafty place that allowed moisture to leave, and it was heated with wood fires that effectively kept it quite dry. Now the modern expectation of warmth and insulation traps moisture. You're already well into addressing the issue with diverting water, redirecting it, etc. For your walls, you can still insulate the interior space but the gap between outer wall and insulation needs air gaps and possibly forced air/fans to circulate the air out. Your interior space would need it too. I do not know what it available in Normandy, but you should review ERV/HRV air exchangers for your interior.
Excellent video, thanks for posting. It is really interesting to hear how your philosophy is developing as you discover more about the problems you are encountering and try to find ways to resolve them. So good to hear that you are not prepared to simply 'wage a war against water' and impose quick solutions, which may seem to improve things in the short term (as you've discovered with the earlier cement render, polystyrene insulation etc 'improvements' have shown) - these simply mask the issues without resolving them. I'm sure that your more holistic approach is the right way to go. Take your time, you'll get there. Best of luck for your second year. Joyeux Noel et Bonne Année!
Fitted a PIV in a damp victorian terrace several years ago, worked a treat. No damp or mould anymore.
These old stone houses are so similar in their current dysfunctions. Our 250 year old Welsh stone cottage had almost all the same problems as yours when we bought it 2 years ago. I applaud your approach and we are obviously on very similar journeys.
We are about to start the final phase of reinstating breathable materials inside the house by breaking off the cement render / gypsum plater / plastic paint on our internal walls. We have settled on hemp + granulated cork + lime putty internal wall insulation. We will be applying it wet directly onto the newly stripped-bare stone walls (after dubbing out with NHL 2) in 2 coats of 20 mm thick render. Then skim the top with a typical lime putty + plastering sand mix and colored lime wash to finish.
The only way out is through. It’s a matter of survival, so push hard. Good luck.
After you handle all the unwanted water intake : roof, chimneys, ground water, etc. and remove all the cement and gypsum based renderings - I'd recommend a thicker hemp/lime render. It's not as effective as the modern insulation materials, but it handles air moisture extremely well and leaves place for improvements at later stages. Also I would strongly recommend you to look at some HRV /Heat Recovery Ventilation/ systems - constant flow of fresh air is a must is these houses and HRV makes it way more economical from the heating standpoint.
I agree. Remove intake, ventilate and only then insulate reasonably well (thinking roof and windows, make sure the walls can breathe). Also you need a steady 15c+ if you want to avoid condensation. You might like cold, your house does not. Something like a modern woodstove with external air intake will help a lot and save some money on cold wet periods.
You're on the right track. Location and materials used for the original build will set the terms of what you need for fixing. As you said, coming to terms with your environment and connecting the home to it is key. I will follow your endeavors to solve the damp issues. Good luck to you and your wife. It's a beautiful building and well worth saving.
Excellent video. Thank you for taking the time to create & post! Looking forward to following along. 👍
We purchased a stone cottage in central Portugal that is also on a similar slope and partially underground. The weather is rainy and humid. We are originally from the US and lived in the desert with humidity often in the single digits. We didn't know how to live in the stone house and immediately started having humidity and condensation issues. Your video and the comments have provided a lot of information. Heat, ventilation and a large dehumidifier have made a big difference in comfort for us. The house was expanded at some point so we have one exterior wall that isn't stone and needs to be insulated but the rest are quite thick and we'll leave them as they are. We have an insulated attic, a new roof and central heat fired with wood. We are very aware of how we interact with the home and what contributes to humidity. Some active ventilation is next on the list. I agree...we are trying to work with the natural characteristics of the home and adapt how we live in it. Best of luck with your beautiful home!
Fascinating video. It's amazing how we are "educated" and yet leave school knowing nothing about this stuff. I also hate how we hide so much functionality, like pipes, behind things and have no way of monitoring them.
You are so right. On-wall plumbing and electrical insulation are not so sexy, but cheaper and faster to install, easier to monitor, to troubleshoot, to repair and to modify.
@@guzziwheeler if you do hide pipes in walls at least document it well for your self or next buyers.
Excellent work so far, keen to see how you progress with it.
We have a solid wall stone house in in the South West UK, experienced damp issues and slowing working through them. Much like yourselves, starting with all the obvious things and monitoring. Now we are on changing the building fabric back to traditional materials, it was hit hard in the 80s with cement based coverings and gypsum. Luckily there are outlets nearby that sell lime based products. Even better, the Somerset Recycling centres are allowing DIY waste for free now (in small quantities) which includes plaster/ plaster board and even asbestos. Happy days!
I would 100% go for lime hemp base coat and 2 x fat lime top coat with no additional insulation. The lime hemp will give a good level of insulation and will allow the walls the breathe. I have recently done my stone house in this and we have zero damp issues and it is lovely and warm. Lime products from Ty-Mawr Wales are excellent although hard to get it to France 🇫🇷 I would fill a van and drive it over. Great project good luck!
Well done, you have done a great job and cleverly researched some solutions.
I respectfully suggest that you look at what Roger Barnes who lives in Douarnenez, Brittany is doing to his house on YT.
He is an architect and sailor but has discovered his old house has a concrete straight jacket around it inside. He is removing that and using hemp and lime to insulate from the inside. Maybe, he might do a joint video with you?
I hope that this is helpful.
Best wishes from Scotland.
As I understand it, the quantity of water vapour air is able to contain is a function of the temperature of the air. Hot air can contain more water vapour then cold air (up to a point).
Exactly. I like to imagine air like a sponge, a peculiar kind of sponge. If the air is cold, the pores are small and the air can hold little water, if it's warm the pores are large and the air can store a lot of water - which becomes a problem when the air suddenly cools, from hitting a cold surface like a window pane or wall. That causes condensation.
My tips. Extent your roof , a 1/2meter be hond the walk. Just like a colombage house. (Prelable needed). Ventilate between wall and isolationisme. Ventilate rooms with heat recovery. Than you can ventilate more, without loss of too much heat and comfort. Inject bottom of walls. Use lime mortar.
@BreatheScotland talk to the maire, show hour problem without video, maybe Also talk to roofer die presidents before you.
that is one very sick house hopefully you guys don't get sick
My thoughts too, my wife got really ill from our house being damp, and although she is now slowly getting better after fixing the damp, it is a long and stressful road that I would not wish on anyone.
@@raverdave9125I am recovering from mould illness too, how long has she been recovering? I wonder if I'll ever be back to full health and I'm 33 ❤
We were in a similar position to you when we bought our house 3 years ago, although we didn’t suffer from water ingress from ground level we had a huge hole on the roof and terrible damp walls due to poor maintenance.
Our first task was to get the roof repaired and the walls made good bit our best investment was an Envirovent Positive Input Ventilation System. Our house was bone dry in less than 6 weeks and it remains completely comfortable no matter the weather. I can’t recommend it enough, no need to run a dehumidifier or have any vents installed, just one unit installed in the loft space and within a few days we could see and feel a huge difference.
We used a foil based insulation mounted to the internal walls. Relatively easy and affordable to install, it’s made a huge difference to how the house feels.
We’re reconverting our basement at the moment. Had issues with high humidity after taking up the damp proof membrane and putting a flagstone floor down on a bed of lime. We installed a heat recovery ventilation unit which pumps air out of the room and brings in fresh air but heats it as it’s drawn in. Has helped massively with the humidity in the house since we installed it- probably worth looking into
The cinematography, music, problem solving, scenery absolutely made this an incredible watch!
I would also look into treatment of the exterior with something like storm shield to allow the moisture out, but also keep any exterior water ingress out. I have used it personally on my own home on a faux stone cladding over a timber frame that can't be insulated and the difference is amazing, dryey, warmer and reduced humidity massively.
Remove all the concrete on the inside. Batten out the walls and mix Strawand lime and create shuttering and loose fill the area between the wall and shuttering with this mix …… then render the walls with hemp Crete which will provide thermal mass and is moisture permeable and has buffering abilities .. It’s also fireproof and will absorb carbon dioxide. The French have been using hemp Creek since the Roman times & it had seen a recent resurgence in France especially, for heritage renovations…. Improve the size of your gutters, so that they capture all water run-off from the roof. (I noticed from your videos that water appeared overflowing the gutters). install a wood burner ASAP this will make your house cosy and toasty warm, and it will help maintain appropriate humidity levels. Remove the soil that abuts the house at the gable end, and at the front of the house and install French drains around the whole of the perimeter just like the one you’ve installed at the rear Install an MVHR unit which will allow you to exhaust humid air and will use the heat in the exhaust there to warm up the external a fresh air as it enters the house. Where are you will not need to open the windows in bad weather. I hope this helps.😊
Thank you for this very honest, thoughtful and thorough discussion of the problems you faced remediating the moisture. Leaking pipes! Ours was house plants… I appreciate too your clear enunciation and speaking speed as I have trouble tracking speech often.
Very interesting. Water is a tough adversary…you seem up to the challenge. First time viewer and I’m coming along for the ride… looks like a lovely property!I’m in Fl so I can relate to humidity issues in homes. Best to you with your reno
Good luck dudes!
Makes me feel a bit better about my very cold and damp, but very small, flat.
Congratulations on taking on this project! It's a beautiful stone home. Hopefully you will be able to validate some of your research with building engineers that specialize in this work. Good luck!
CZcams needs to make a love button just for this video.
THanks for sharing your journey with us.
thank's for sharing ,of course it'll be a long journey but you will,and that's the most important . Keep going never surrender
Držím palce,dúfam že sa podarí zvíťaziť nad tou zákernou a otravnou vlhkosťou.
Had same problems, what helps a lot is wood stove... so higher temperature force moisture out. For some situation recuperation is also nice (even local one for most used places)
Have you checked what was used at New Orleans back in the Katrina hurricane?
Because of the floods, the damage caused by water, humidity and mould, they used CIO² to get rid of the mould.
Check it out, you will find many videos that shows you how to get rid of damp smells, get rid of mold (more effective thant bleach).
You are doing a great job with that house, ventilation, more windows and doing something with that well under the house, you might need to pump it all out and somehow making sure it doesn't fill up with water.
If you have a chimney, use it. Get a wood stove and light it up, fire sucks all the humidity out and chimney acts as ventilation in the summer. Stone houses can not have insulation inside, remove it. If you have thick walls, it should keep warm, because stone is generally good at heat capturing. It just takes a long time to warm up, so don't let it go cold once it is warm. What you need is a large stone stove with a circulating heat wall and an insulated roof. Today there are also solutions like automatic pellet stoves that go into cellar etc. I live in cold climate and used to live in one old stone building with thick walls with no problem. How thick are the stone walls here?
Thanks again. I have a barn project that's going to become my kitchen... Stone walls... Embedded in a slope... So very, very interested to hear what you learn about insulation.
Sounds like you are on the right track. Hemp/lime/perlite insulating plaster internally; lime pointing and possibly lime rendered externally. You can see the rough rendering - schlaistering they call it in Scotland - was the original finish.
And get some heat in to push the moisture out. Good luck, a great project.
i had a similar issue in France. i fitted a whole house ventilation system and it works great.
A difficult situation, it makes me think of a farmhouse which was right on the edge of a river, very beautiful in summer, but in winter and autumn, rotten by humidity and it happens that it rises in flood and it is the catastrophe, the house never found an owner and fell into disrepair. I have a family farmhouse in Brittany (quite similar to Normandy), some work to do and I came across this channel, but at least my base is dry, good luck with your project!
I dealt with this issue in my own stone cottage which had layers and layers of "damp proofing" aka cements applied to the stone walls. The walls were dripping wet, black with mold and icy cold to the touch. We used a jack hammer and broke it all off the stone which was soaking wet underneath. Repointed in lime and lime washed the stones wall directly. Never had an issue again, took less than 24hrs for the wall to dry. We had so many people tell us we should have damp proofing courses, more concrete or even inject silicone into the walls! All absolute nonsense. The house even smelt better afterwards. Everything you are doing to far looks great, a log burner will help everything significantly!
For the insulation and rendering of old stone walls I once used Multipor and am very pleased with it. The climate in the rooms improves, mold was no longer an issues and it was quite easy to install. Not cheap though.
With a bit of inventiveness, you can even lay electricity cables through it.
In our other house, old/ natural stone too, build in 1583, we did something else, as the walls were just not straight enough for Multipor bricks. We made a wooden wall about 10 cm away from the stone wall (all old plaster and cement removed first !!!) and poured so called thermo plaster (Thermo Putz in German) inside of the gap. After curing the wood was removed and the walls only needed a final rendering (and paint that can breath) It's very light to work with, can breath, insultes a bit, you can pour cables and water tubes inside, etc. You can plaster it onto the walls, but in layers of max 2 to 3 cm at a time. We poured it as it went faster and the result was straight walls.
Old stone walls never have a damp membrane at the foundation level, so humidity will come in there and needs to get out somewhere else. Injecting such membrane is sometimes possible, but often these walls need a level of humidity as the clay or other materials used in between of the stones would otherwise dry out and crumble. We were told not to do it, as it would endanger the structural integrity of the house
Interesting. I've not heard of Multipor before. We've also received advice regarding the walls needing a level of moisture so they don't dry out. Thanks.
+1 for Peter Ward videos
I might take a slightly simpler approach as others have indicated. First stop as much of the water coming in as possible (drainage, ground levels, sump pump, leaking pipes, repointing with lime mortar, roof and guttering etc.). Then allow the building to dry out as much as possible (remove cement/gypsum based coatings, add mechanical ventilation and heat the building properly (10-14degC is too cold to improve or even properly assess your humidity situation)). Then you can install your breathable insulation option, internal floor work and permanent heating/ventilation system. The dehumidifier is going to do much until you can limit/manage the moisture ingress.
When creating a second skin for such a wall, it's sensible to ensure there is air flow inside the cavity you are creating. I have dug up floors to create an underfloor void with ventilation, linked through the cavity, to the loft. So far, the houses remain warm and dry. Make the outside as dry as you can, via pointing and an effective roof and gutter system, and get the water away from the property and not into a soaker. Then keep the inside of the outer leaf as clean as you can - remove the render - so what water gets into the wall can leave as fast as possible. Water will always penetrate a wall, that's the whole idea of a cavity - it creates a dry inner skin - so you must allow it to leave again, generally through evaporation.
I live in an old stone house and just got new double glazed windows with an inbuild ventilation system to make sure that there is a constant airflow and no chance for condensation at the windows. That might work for you, too.
If it comes to heating, have you thought of pellet heating? You can even include them in a smart home system. Which makes it very comfortable.
Weirdly the double glazing on the front of our house doesn't have vents! We are installing a ventilation system too.
Hi there, great stuff, we live in a housw like this and have managed to get rid of damp by using a hemp lime and perlite mix from Tim at Edenlime. Our house is 55m^2 and 3 of us managed to live in it whilst we did the work. Four years and our downstairs is completely mould free even with a Sofa against the wall for a couple of years.
The dehumidifier is sampling the output air AFTER being dehumidified. It is undiluted "lower" humidity air that then mixes with the room air. The dehumidifier isn't sampling room air.
I love your approach - the house exists within an environment that needs to included in your solution. A shotgun approach because you have so many sources of moisture within the building from hidden leaky plumbing, water ingress from the garden (now hopefully solved), and water coming through the roof, walls and chimney. Each repair will help address the problem and the only fix will be a holistic one.
This was also my line of thinking. The number on the display is not the humidity in the room, but the treated air leaving the vent.
good luck you guys. Yes cement render the scourge of solid stone walls. I've put "Storm Guard" waterproofing on the outside of my house as featured by Skill builder being breathable but doesn't discolour the brickwork. That may help with water penetration on the outside walls.
Here in North Island of New Zealand the weather would be very similar to where you are. Here it’s common to have heat pumps in every room, running continuously ( but set to warm and dry) which removes damp from the home. They are also cheap to run. You have to use the natural products, the hemp and lime sounds like the best way to go. Any modern materials will stop the home breathing.
I fought a similar battle on the house we had in Wales. Absolutely key contributing factor is air flow, it lack of it. Once those nice sealed double glazed units go in, your once draughty house keeps all the warm moist air inside. The air cools on hitting external walls, where you'll see mould, especially where there's little air movement. Like back of wardrobes and under stairs space. Add trickle vents at all windows and install constant running low speed extractors to keep a steady flow of air through the house. Obviously not a roaring gale as that just sends all your heating bills up. Be very wary of any exterior treatment to walls. One, they often just don't work. Two, they reduce the ability of the wall to breathe and evaporate away moisture, which they need to do. I would expect the mortar is lime based, so another issue is later work may have used cement based mortar which doesn't allow water vapor movement.
You are going in the right direction. Don't apply lime indoors in the winter! Lime mortar is NOT like cement - it gives up its moisture as it sets/crystalizes. Only apply indoors when you can ventilate for at least two weeks afterwards, or three, depending on depth of lime. It does work, however getting the water away from the house in the first place is the ideal. (Every drain, gutters included, should drain downhill to 'daylight'). Keep the water away from the house.
Rising damp is the biggest issue. Think about the earth as a giant heatsink sucking all heat from your home. When the walls are dry they have improoved u values. Dry walls make a dry home. You are already mitigating site drainage well. Consider the following improvements. Increase the overhang on the on the roof as much as possible. Hemp and lime is a great idea. Route the roof downpipes away from the house.
If you choose to dry line the walls you need to make install vertical 2inch buttons then horizontal buttons then dry lining. It will mitigate thermal bridging. Core out 100mm vent holes in external wall and install non return vents to allow the wind to blow through the cavity. Minimum 2 per side you dry line.
If planning allows, cement dash the the outside or external wall insulation. The goal here is to move the dew point to the exterior.
Great work, best of luck.
Ive been renovating a Scottish farmhouse for the last 5 years, and pretty much have had all the same issues, and done similar improvements. Best thing for keeping the damp under control... 2 wood burning stoves and a Rayburn. Nothing compares. They just dry the house. You have to keep the heat at a decent level too! Even if the oil bill is costly.
My house is Granite stone, that has also had cement render reapplied in the outside joints about 15 years ago unfortunately, an old internal render in places, then lathe and plaster internal walls, or new stud walls with plasterboard and foil backed insulation etc. I try and remove the old internal plaster where I find it. As long as you keep an air gap between the stone wall and the back of the stud wall and allow airflow to keep the cavity dry. Old and new materials work fine together. The Scottish wind helps! I've done similar to you and dug new drainage for the downpipes and for the footings to help keep them dry. Front half of the house is single glazed sash windows. Polycarbonate secondary glazing made a big difference to the house temp, and a window vac helps remove the condensation from the remaining single glazed windows... These sort of act as a dehumidifier in a way and sucking off the water each morning I've noticed helps in reducing humidity. A whole home MHRV system imo is the best way to go for these sort of houses. Again, a wood burner is actually the ultimate, as it gives of a nice dry heat.
I live in a stone cottage myself,
Few lessons that might help you.
Open shower window no matter how cold it is.
Open windows on a cold dry day for 15 mins
Leave doors opening
You need more heat in the rooms .
Dehumidifier are good once you get on top of it , life be much easier .
Have you looked into a Piv unit?
I wanted to express my admiration for your interesting project. I can relate to the challenges you are facing, as I have encountered similar issues with my own house, which is constructed with wood. The dampness has caused the lower beams to rot (replaced them last summer)
In order to address these issues, I would suggest starting by identifying and eliminating any leaks in the roof. Additionally, removing all polystyrene insulation and rendering the walls with lime mortar could greatly improve the situation. If possible, installing piping in the walls for radiant heating would be a beneficial addition. But sometimes temperature of radiant heating is to low to fight humidity if walls are dump.
Taking the necessary steps to remove any additional sources of dampness is a logical first step in this process. I want to encourage you to remain hopeful and not lose sight of the potential this house has to become a beautiful and comfortable living space.
Wishing you strength and endurance throughout this endeavor.
Sincerely,
Emils
Major progress for 1 year, way to go.
I think that your work is very good. You will most likely figure out all the problems, bit by bit.
On a much smaller scale, but we have the same problem. We also measure the humidity in our rooms and try to ventilate by opening windows at least once or twice a day. In the longer term, central ventilation with heat recovery seems to be the only solution, but we don't have the budget for that at the moment. It is worth reading up on the subject, there are many advantages.
Hi, great observations. some points that may help your renovation.
1. Shield the house from exterior water (waterproof roof), drainage around the back as you made, waterproof coarse at the foundation etc.
2. Replace all non breathable surfaces on the interior. When the rain around the house is taken care of you might still have to deal with the ground water. (moisture)
Moisture can get trapped under concrete/stone/tiles solid floors (any non permeable material) and will escape though the stone foundations to the walls. This can cause the mold and eroded mortar on the interior
3. Heat the house sufficiently, an old house like yours should ventilate enough with the windows closed...
4. Insulation could be hemp panels mounted directly to the walls (after the previous measures have proven to decrease the humidity sufficiently)
5. You could connect a heat pump or the fireplace to underfloor heating and direct it through some problematic places (e.g. a moist wall or damp wall around a window where the wall is less thick)
You need to replace the electrical decentralized heaters by a central system with more inertia. The graphics show a delta T of around 10°C, that's too much. You should try not to exceed a delta T of 5°C. The cement render and the false walls with EPS insulation are a nogo, but you already know that. Because of the massive walls with natural stone there will always be transport of moisture between the inside and the outside. It is therefore primordial to use breathable and buffering materials on the inside. Your choice of hemp is a good one. Besides being able to breathe the materials should also augment the inertia of the temperature. The overflowing gutters should be tackled immediately, to reduce runoff on the walls and splatter at the botom. The drains are a good thing, but you should also place a barrier between the outer walls and the contactsoil.
14:40on the inside you can seal the stone work off with a 1" air gap for drying, then insulation and Vapour Barrier . you connect the air gap all the way up to the attic vented space . the coating to the inside of the stone walls needs to be removed at least mostly removed anyways. that wall needs to have a gap that actually is vented top and bottom. you can probably vent the bottom inside air gap to the outside thru the stone wall. the outside wall needs to be a rain screen, then the insulation and attic is the dry heated conditioned space.
... bit by bit, little by little - and step by step you will be able to solve your problems. This is a very good video -- In many ways. Best of luck for the forthcoming work. Greets H.
Sounds like a 1980's renovation job in Normandy / Brittany. Cement everywhere, as it was cheap at the time.I have to repoint my mother's house with Lime mortar due to creeping humidity (although not as bad), and I'm not sure what to do with concrete floor. Drainage, and more drainage.
We learnt to live with the house, washing cloths if it is 50-60RH hanging with a pullie under the kitchensealing. Electricity got to expensive to waste for us.
We got moisture under control comparing CO and RH, thinking low CO means high O2 and better ability to get warm.
Temperature doesn't matter, we keep 12.5° in Winter and it is fine, we just open the windows if it is like 1000CO and close it, if it is down to like 550CO.
Having a clean gutter is important... gamechanger.
At time at weekend evenings we fire the oven but just in winterperiod. Sub Zero temperatures are bonedry, we use them to get RH down. We got windows open all summer.
Insulation is always weird thing, we did insulate outer walls and roof and did use silicatepaint, cos mold needs organic walls, so we got told.
Outside you did make a huge step. Try to keep earth away from your walls. We got alike problems, slope and alot of water. Good luck. :)
Worked for years in the States in the hazardous materials remediation business but your situation is quite different from what we encounter here. These old, old homes were meant to breathe and were likely damp and drafty years ago round. Simply washing the walls with a 10% bleach solution would have been an ongoing mission.
All I can say is, if you start getting headaches, nasal or breathing issues you need to get PROFESSIONAL HELP.
Sounds from the comments that there is a pool of specific advice available-but, how much is valid and how much is simply here-say is the issue.
Good luck.
We feel your pain! These old homes are beautiful but perhaps they were meant to be used as they always were, with an open fire that dries out the house, and uncovered walls with lots of ventilation. Beautifully written video
If you have a south-facing property with space for a panel of about 2 square meters, you can try a solar air heating system with humidity control. This is how I reduced the humidity in the basement of a vacation home in Brittany by about 10%. It heats a little and also extracts humid air when the outside air has less (absolute) humidity. It costs quite a bit of money, but on the other hand it only needs some power for the fans when the sun isn't shining (it also has solar panels for the controls and fans). This house has ~40cm thick stone walls and is more or less standing with its feet in the water (very high water table). I will install a second heater next year, but first on my list is a new drainage system around the house.
From watching another CZcams channel with a 100 year+ old brick house in Belgium. The went with hemp insulation for the same reason as fighting the damp and keeping the house breathing.
Many houses, even the super-nice ones, have Rising Damp, where the old houses are frequently built on a dirt foundation (roots, rocks and all) rather than concrete. On top of that, if you breathe, and I hope you do, the house becomes more humid. In part, the old single-pane windows let air through and help with humidity, so while double-glazed windows are more comfortable, they can seal in the moisture. Placoplâtre looks awesome, but if you are covering stone walls, they still have to breathe, meaning if you stick with the traditional limestone plaster still in use today (chaux), it will absorbe the humidity, unlike the modern impermeable paints that contain plastic and can quite literally rot the walls. Damp courses are a popular solution, of course, but there's definitely a cost to that.
You live in a cave. In a rainy area. The only real, long term solution is to insulate (hard poly boards) the outside of the house down below the frost line. Knowing local regs won't allow this leaves you with a dilemma. Recreating the original stone work 'look' will require new stone work over the new insulation/vapor barrier. It does not need to be thick, a tilt wall system of thin stones will do. You have to move the dew point outside the original walls. This also requires extension of the roof. So there is no easy, cheep fix. It's why these piles are for sale and the locals don't touch them.
I love your comment about living in a cave. We have a stone cottage in central Portugal that is semi-underground and it's rainy where we are. We often laugh that we're actually Hobbits now! 😊
Somebody else may have mentioned it already but a common solution in older buildings based on moisture management rather than exclusion. Providing physical impermeable barriers on the inside such as cement render are rarely successful as the moisture migrates elsewhere and the building cant breath. An alternative solution is to use a cavity drain system with a cavity drain membrane and sump tom manage the moisture. This type of system is used in basements successfully. The cavity permits moisture to move around and by appropriate detailing the insulation / support frame can be suitably isolated from the damp. Looking at the walls there is a lot of pointing needed, don't underestimate the issue of penetrating dampness, this also needs to be addressed. I hope this is helpful.
Unfortunately these old stone buildings weren’t built with the modern concern we have of -: damp, consistent temperatures, maybe not even comfort.
I’ve worked on many grade one & two listed buildings where we’ve over come these issues.
The very best old houses that I’ve come across with existing methods still in tack after 2 or 3 hundred years are Bulgarian farm stead’s.
I own a few and even after leaving empty for some months they are never damp when we return
A range of 10-14C seems to be very low. We keep our old building around 15C-18C all the time.
Regarding humidity: Warm air can absorb more humidity and will release it when getting colder.
*Cold air cannot absorb as much humidity as warm air.*
If you see the absolute amount of water in the air as a constant, cold air will appear more humid since it cannot carry as much of the humidity while warm air will appear more dry since there is more "space" for the humidity available. That is the basic meaning of relative humidity. It shows the amount of used capacity in the air. If you have great swings in the temperature, you will have more condensation problems. the warm air will absorb more water and it will release it when it cools.
It may be that by removing the humidity in the air, you just pull more of it out of the walls and floor creating a kind of wicking effect.
A dehumidifier works by cooling the air to release water from the air. Afterwards it will be heated (by the other side of the cooler) in the dehumidifier. If you have higher temperature in the house, more water can be carried in it. But the water will condensate more easily on cold walls and windows where it cools.
You could try to replace the water in the walls and floor with something else that does not evaporate as easily, basically creating a barrier that prevents water from getting to the surface of the stone. The previous owners tried that with concrete and cement. But cement will act like a wick, drawing water out of the sone. We had good experience with water-glass (sodium/potassium silicate) in the past. It is no universal solution but it can saturate natural stone and prevent water from seeping out of it, or at least it reduces the amount of wicking the stone has. Sometimes a solution of borax and water-glass is used to create a mold-preventive coating. There are more professional solutions on the market that will most likely create better water barriers. You can also use calcium-silicate boards to prevent the growth of mold (because of the PH of the calcium silicate).
You can not create vapor barriers in the stonework. The water need to move through the stone wall and dry out on the interior of the house. Walls have to breathe or at least solid stone walls need to breathe. He also needs material that has the ability to hold water and release it slowly. That is a good job for hemp or wood fiber to do. Clay hemp on the interior wall or hempcrete (lime and hemp) could also work. Both have a high capacity to hold water releasing it slowly.
Yes, my reaction, FWIIW, would be to repoint the outside of the house with a lime based mortar, re-roof incorporating a permeable membrane sarking, fit a rainproof chimney cowl and ensure the rainwater goods are functioning optimally. Install a woodburning stove with appropriate flue in the chimney to bring the internal ambient temperature nearer to 16 degs and drive some moisture from the endwall in particular.. Then I would take stock and see what further measures, such as insulation and ventilation might be needed.
@@avisitorhere The main problem here is not air humidity, but "cold walls" and so humidity condense on a cold wall. Solution is thermal insulation of the wall preferably on the outside, and with stone wool.
@@avisitorhere Creating a complete vapor barrier is not really possible (as i said). The goal would be to *reduce evaporation into the house* by changing the properties of the rocks in the walls. The walls will take on moisture rom the outside and it can release it back to the outside. The moisture inside the house has to be managed as well. Humans breathe and the moisture contained in the air has to go somewhere. _The current situation is that too much moisture is introduced from the outside_
The first step is to manage the moisture intake and prevent the moisture from being trapped inside. There are multiple problems and hemp or lime mortar will not fix them all. The humidity in that region is very high (around 85%) and that alone will make it hard to get a good room climate. If there was some easy fix, the previous owners would have done that.
1st *reduce* the moisture 'intake' from the outside,
2nd *manage* moisture produced inside.
@@john_ace Yeah, he has a whole bunch of problems from no interior ventilation, bad gutters, bad windows, leaky exterior walls, wicking up from the ground, leaking roof, he's definitely up to his neck in problems and lime create will not fix any of them alone. But there will come a time when he's fixed the major issues and begins pulling of the cement plaster and looking to add an insulation barrier to the inside of the home and hempcrete or clay and hemp or some other breathable system will help a lot. But he just has a ton of issues that are allowing moisture into the home right now. And I also would be skeptical in thinking that water from the outside can turn around in the wall and be vented back out to the outside or that water from the inside can be controlled without wanting to move out into the walls. The walls breathe, you gotta work with that system.
You're absolutely correct in your suspicions - older houses, ESPECIALLY an extremely old stone house like this absolutely is not capable of being a tight construction like a new build modern home. The stone and the lime based mortar all breathe and transmit the temperature and dampness straight through the walls. Concrete is not nearly so permeable and so while it will help to some extent to stop intrusion of moisture, it will also trap it inside as well, and cause added condensation.
These homes worked because they could expel the dampness of our day to day activities, albeit at the cost of being connected at some level to the outside environment, which is why you'll never win if you are at a RH of 80% for extended periods. I think you're on the right track though to make it livable. The added drainage, maintenance of the structures intended to shed water (roof, gutters, lime based mortar in the stonework if it was ever replaced with concrete, etc), and interior ventilation will go a long way.
Materials you should be looking at are lime mortar and plaster, as Jon said below, use a traditional fireplace/stove to help drive out moisture (this was an essential component of these old houses), and just accept that above a certain point you will not be able to win against the moisture and you need to build to suit it.
One final thing you can try - see about building out some form of rain garden behind your new patio area, at least 10' away from the house, and give a course for overflow water to flow away from the structure. There are calculators online you can use for this. Use local wet adapted plants to help suck up and aspirate away the water as it builds up and sink the water into the ground.
Once the drainage is sorted outside the house and the roof is sound, I would recommend you dig out floors to whatever level is required, fit a membrane and then construct an insulated floor with under floor heating installed. I definitely would not cap off the chimney, it needs to be re-lined with a thermocrete solution or similar. We live in a Victorian stone-built house in Derbyshire, our chimneys were damp like yours, but since the thermocrete lining was done 20 years ago, our issues have disappeared and we now have usable chimneys which will take a real fire, log burners, gas firs or whatever else we wish to use. The cement render on the inside walls definitely needs to come off, we had the same in our cellars and it was a disaster. Once you have the exterior walls re-pointed, I would suggest you apply a breathable plaster (you can get modern ones that contain vermiculite that also add some insulation). You may have to accept that the house is never very thermally efficient, but the key is tht it must be able to breathe. I would also recommend an air source heat pump to power underfloor heating, these devices are designed to be run low and slow (left on all the time to maintain a steady internal temp). This would heat the mass of the house and allow it all to act as a large thermal store, whilst keeping your heating costs reasonable.
If you plan to insulate, leaving an air gap like you talked about with weep holes at the base of the exterior wall will allow the humid air trapped
between to escape.
Use a non vapor permeable membrane between the interior and exterior walls. Mount the membrane to the outside of the interior wall so as to maintain the air gap. Do not place directly on the stone wall. Im guessing that is what was intended by using the prior insulation (polystyrene). They had no weep holes to allow trapped moisture to escape outside. Some forms of stone and pretty much all mortars are porous. This means when the stone wall gets wet water permeates into the wall. When the sun comes out and dries the surface of the stone wall outside, it pushes moisture into the interior. This is why the wall needs a weep.
Another possible solution beyond the weeps is extending the roofline further beyond the wall. Stone and mortar that is not wet, does not need to dry.
Drains are good. Consider the slope of the grade towards the home. IRC (international residential code) has specific requirements for grade of slope away from a residence over a specified distance. Consider using the IRC as a guideline.
Do not misunderstand. Water is the number one enemy of a home and its occupants comfort. Learn how to mitigate it and you will be better off.
Very best luck to you both.
I have an 1880 victorian brick semi very close to the River Test in Hampshire, England. Therefore it's damp. No damp proof course but every few years I have the old lime render taken out and new lime render, plus breathable paint put back. It's a pain in the arse. I guess I have to be philosophical about it and just think to myself "it is what it is 🥴😁
Just like to add that the paint I used was by a company called 'Zinsser"
Very interesting topic and video. Thanks for sharing.
Just some thoughts from me:
Also the tumbler let's same humidity into the room. Mine does it at the very end of the process. I can feel and measure it in my little bathroom. You can try it also.
As the tumbler has a efficiency class for the energy consumption, so it has for the condensation efficiency. If you buy a new one someday just look on the labels and compare. Or you can get one with a hose that sends all humidity right out of the house - but maybe you don't want to drill a big hole in the wall.
I also have 5 humidity sensors and they don't show the same values hence they are not calibrated. I compared them at the same time and please and told the value in the middle of all to be the truth. You could also buy a more expensive an precise device for one measurement and then send it but. That is maybe not fair, but in your tough conditions?
And what about your flowers? Don't they "sweat out" some humidity?
With kind regards
Edit: Maybe you are interested in some options for isolation which can handle steam and moisture? But it is German czcams.com/video/mV7hwGVNqOo/video.htmlsi=1exllQX_06GeBQCm
He also covers topics like ventilation and so on as he also lives in old building.
@13:52 That chimney isn't lined and the gable is permeated with decades of tar and the stonework is rotted/ruined. It's not rain, I had the same. The stonework needs cutting out, the chimney lined with fireclay pipes set a weak lime mortar mix, then the stonework rebuilt. You can later draw a flexible metal flue pipe through the lined chimney for any stove.
Also @15:11 you should line your French drains with geotextile, including closing over the tops. Water will still drain through it, but otherwise they will silt up and clog with roots in a couple of years and you will need to dig them out and start over.
Effective gutters and drainage a must-- have you considered "breathable" masonry sealant? We treat lower foundations when there is splash from a gutterless roof. I've solved most of my water issues with proper grading (cheap!) Good luck!
Similar issues back in the uk in a red brick terraced house. Everyone on the street damp proofing to the heavens and with cement renders and the lot. Eventually taking ours right back and using lime insulating render on the lot. Already seen a 10%+ change just taking 1m off the cladding on the front.
I have some suggestions, however with you living there you will know best if it's wise to apply these suggestions. Firstly, I live in a 1920's house, of cavity wall construction. A wise move may be to keep an air gap of sorts, much like what you described finding when you pulled the bathroom out, but then adding air bricks to the outside of the property to allow air to circulate freely inside of this air gap. With enough insulation on the interior walls you shouldn't see any drastic reduction in temperature. I'd suggest having a damp proof course installed to prevent the rising damp as well. Also make sure when you get your loft done that there's a good amount of ventilation in the loft space, as humidity tends to rise and gather in the loft space. When you replace the roof, have an overhang placed on the gable end wall as well as an enhanced overhang on the eaves, this will stop the wall getting soaked from above, coupled with the damp proof course to stop it being soaked from below. In addition the extra vent tiles and vent bricks will allow the house to breath much more effectively. I think your idea to go back to lime mortar is a brilliant one and will aid this process massively. It may also be wise to install a concrete pathway around the exterior of the property with a slight slope away from the walls, perhaps into the drains you've installed.
Best of luck my man, that's quite the project you're undertaking, but stick with it and you'll be rewarded with a lovely house.
Have you considered keeping the chimneys open, maybe just putting an open cowl on them?
Great video, lining in s Victorian cottage i can relate and feel after 30yrs we’re winning. Humidity now averaging 56 around the house. Took a lot of work and change of routines.
Will follow with interest.
I recently watched an old mill renovation. Grand designs, lots of damp issues there, they used a lime plaster/render with polystyrene balls mixed in that went straight onto the interior walls. They seemed to have success with that.
Cornish flour mill bought 2017...is on youtube.
You might consider a heat recovery mechanical ventilation system. Bring fresh air from the outside and exhaust stale, humid air to the outside. A heat exchange will capture the heat from the air being exhausted and heat the incoming fresh air. You will need to run ducting to each room. I think this approach is a better solution than just punching holes in the wall for fresh air. Something to research as you develop your project.
Great video - explanation is sound reasoning ...