To avoid the expense re-roofing a house that is simply suffering from nail fatigue, and to obtain optimum insulation, an 85mm layer of polyurethane foam can be sprayed onto the underside of the slates or tiles of a pitched roof. This stabilises and weatherproofs the roof by fixing the nails, battens and roofing felt. As the foam is a superior insulant, coupled with just 100mm of insulation at joist level, your roof will also meet the stringent thermal performance standards required for a new home. A typical roof can be insulated using the polyurethane treatment for around half the cost of re-roofing.
Open-cell is also known as half-pound foam. It has an R-Value of 3.5-3.6 per inch, and its density is bout 0.5 pounds per cubic food. Low-density foams like these are made partially from raw biological materials Carbon dioxide or water is also used in the makeup. Open-cell uses far less material than closed-cell, but its R-Value is lower. Also, open cell requires a vapor retarder (like gypsum wallboard) and is riskier when used for roof sheathing. It's not highly recommended that you use open-cell insulation if you live in a cold climate unless you have that extra barrier. You should also compare how much money you spend versus how effective the open-cell insulation is wherever it's installed.
Another thing we love about the Liquid Roof is its ability of not being damaged by freezing and other extreme temperatures. You will also appreciate its ability of staying flexible for a longer period of time. Did you know that it could also contract and expand as you roof moves? That is one of the things to look for when shopping around for this kind of product we found in the Liquid Roof.
For maximum durability and leak resistance, we recommend that two coats of topcoat be applied at 100 sq. ft. per gallon, or a minimum of 20 mils dry coating. If two complete topcoats are not applied, always apply two thick coats to problem areas such as scuppers, drain areas, ponding areas, seams, and repaired areas. Avoid using Elastek Solar Magic™ or The Shield™ on ponding roofs. Clean skin and tools promptly with water. http://www.youtube.com/watch?v=ggLAUsiuI_o&feature=kp
Global warming potential (GWP), as defined by the EPA, is a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (CO2). Spray foam insulation products that use water as the blowing agent - typically open-cell foam however Icynene’s ProSeal Eco is a 100 percent water blown closed-cell spray foam – have a global warming potential of 1, the lowest possible number. This is because water in the mixture reacts during the application process to release carbon dioxide and heat. The GWP of the blowing agent is that of carbon dioxide. Carbon dioxide has a GWP of 1. https://www.youtube.com/v/ggLAUsiuI_o&feature=youtu.be
Sean, thanks for jumping in and answering John's questions. About choosing the right foam, I intentionally avoided the open cell vs. closed cell foam debate. I did this partly because it's worthy of an article all by itself, but mainly I didn't include it because, despite all the warnings the two sides issue about the other, I've never personally seen a problem caused by using open cell where they should've used closed cell or vice versa. I'm sure things like that happen; I just haven't seen it yet.
Fill and seal expanding foam sealant is urethane Fill and seal expanding foam sealant is urethane foam designed to fill large areas quickly and permanently. Uses include filling holes cracks or gaps that require a complete airtight and waterproof seal but are too large to be filled with ordinary caulk. The foam expands approximately 3 times its original ... More + Product Details Close