Although manufacturers will tell you this stuff is breathable, we show how interstitial condensation on an open cell spray foam can cause elevated damp meter readings.
Interesting video and thanks for sharing. I will say, as a manufacturer/distributor where we've very recently had our foam BBA certified that I can't agree with your comment about "manufacturers will have you believe it's breathable" - this kind of comment paints us as cowboys when indeed, we are serious organisations. The open cell foam is indeed breathable with a low resistance to moisture hence the reason moisture reaches the membrane in the first place. In your video, what you are actually referring to is the non breathability of the roof membrane where there becomes a heightened risk that moisture will penetrate the breathable foam and then become trapped at felt level in the outer 1cm layer. The content of moisture so far as I can tell, is well below the threshold of 20kg/m3 and I'm guessing this assessment was carried out in autumn/winter months when there is a natural increase in moisture regardless of whether foam is installed or not. Importantly, we commissioned a study which we will release soon. It's entirely independent and I think provides all the answers we all need. Open cell foam applied to bitumen (non breathable) felt "can" drastically heighten the risk of water content in the outer 1cm layer. In fact, that risk can be as high as 95kg/m3 based on medium to high moisture loads in the home. During the summer, there will be a natural drying out phase but there remains a risk that the insulation assembly will not fully dry and that the insulation becomes saturated on a compounded basis, year on year. The solution, which we have scientifically modelled through an independent third party body, states that a vapour control layer on the warm side will vastly reduce the ability for moisture to accumulate within the assembly, making it vapour closed. This risk reduces to 4.5kg/m3 in the highest risk zone in Aberdeen (further down the country, the risks become even lower). In addition, the formal recommendation is for use of an intelligent membrane that promotes bi-directional vapour drive with the membrane closing to stop moisture penetration where humidity is higher in winter months. Conversely, in the summer, the membrane opens to release any moisture that may exist in the insulation assembly, if indeed there is any. This is particularly useful should any driving rain penetrate through imperfections in the roofing membrane. I'm happy to share our independent study with you once we formally release it in March. Be rest assured that we are committed to finding solutions that totally derisk spray foam installations. Other manufacturers are also working on their own methodology so I can only speak for ourselves that we follow the science and intend to make VCL's or intelligent membranes mandatory on any installations directly to high resistance roofing membranes. I think it's vital the spray foam industry as a whole, listen to concerns but I think it's equally important that when the industry come up with solutions, particularly those from non related third party scientific bodies, that the information is considered and our voices are heard. I understand there are concerns and I definitely don't disagree with some or all of those but in an era where energy conversation is important and there are a multitude of products available, each is allowed their right to exist provided installed correctly, guided by the science. Many thanks, Richard
Thanks for posting this. When my husband and I watched this we thought we would try and look under ours to see what we were dealing with. The battens are rotting away. Im gutted. We moved in 2020 and the insulation was already installed, no issue or questions regarsing mortgage at this time. What do you advise as next steps? We are unsure where to go next.
Hi, thank you for your comment. I am so sorry to hear this, it is vile stuff and should never be installed. I’m not sure if you reference to battens is the tile battens, which means no underlay, or the rafters. Please pop me some photos on email. Thank you. Neil
Interesting video and thanks for sharing. I will say, as a manufacturer/distributor where we've very recently had our foam BBA certified that I can't agree with your comment about "manufacturers will have you believe it's breathable" - this kind of comment paints us as cowboys when indeed, we are serious organisations. The open cell foam is indeed breathable with a low resistance to moisture hence the reason moisture reaches the membrane in the first place. In your video, what you are actually referring to is the non breathability of the roof membrane where there becomes a heightened risk that moisture will penetrate the breathable foam and then become trapped at felt level in the outer 1cm layer. The content of moisture so far as I can tell, is well below the threshold of 20kg/m3 and I'm guessing this assessment was carried out in autumn/winter months when there is a natural increase in moisture regardless of whether foam is installed or not. Importantly, we commissioned a study which we will release soon. It's entirely independent and I think provides all the answers we all need. Open cell foam applied to bitumen (non breathable) felt "can" drastically heighten the risk of water content in the outer 1cm layer. In fact, that risk can be as high as 95kg/m3 based on medium to high moisture loads in the home. During the summer, there will be a natural drying out phase but there remains a risk that the insulation assembly will not fully dry and that the insulation becomes saturated on a compounded basis, year on year. The solution, which we have scientifically modelled through an independent third party body, states that a vapour control layer on the warm side will vastly reduce the ability for moisture to accumulate within the assembly, making it vapour closed. This risk reduces to 4.5kg/m3 in the highest risk zone in Aberdeen (further down the country, the risks become even lower). In addition, the formal recommendation is for use of an intelligent membrane that promotes bi-directional vapour drive with the membrane closing to stop moisture penetration where humidity is higher in winter months. Conversely, in the summer, the membrane opens to release any moisture that may exist in the insulation assembly, if indeed there is any. This is particularly useful should any driving rain penetrate through imperfections in the roofing membrane. I'm happy to share our independent study with you once we formally release it in March. Be rest assured that we are committed to finding solutions that totally derisk spray foam installations. Other manufacturers are also working on their own methodology so I can only speak for ourselves that we follow the science and intend to make VCL's or intelligent membranes mandatory on any installations directly to high resistance roofing membranes. I think it's vital the spray foam industry as a whole, listen to concerns but I think it's equally important that when the industry come up with solutions, particularly those from non related third party scientific bodies, that the information is considered and our voices are heard. I understand there are concerns and I definitely don't disagree with some or all of those but in an era where energy conversation is important and there are a multitude of products available, each is allowed their right to exist provided installed correctly, guided by the science. Many thanks, Richard
You should consider amplifying your audio by around 200% or more in your video editing software. Kind regards.
Whats that hand tool meter you are usinh called?
Hi, it’s a Protimeter MMS3
Thanks for posting this. When my husband and I watched this we thought we would try and look under ours to see what we were dealing with. The battens are rotting away. Im gutted. We moved in 2020 and the insulation was already installed, no issue or questions regarsing mortgage at this time. What do you advise as next steps? We are unsure where to go next.
Hi, thank you for your comment. I am so sorry to hear this, it is vile stuff and should never be installed. I’m not sure if you reference to battens is the tile battens, which means no underlay, or the rafters. Please pop me some photos on email. Thank you. Neil
Does installing a vent card that allows a 50mm air gap between foam and felt not mitigate this risk?
Hi, thank you for your comment. The foam is stuck to the felt, so there is no gap for ventilation