Liquid Rubber is generally fine when applied in one coat at a 20 mil film (42 sq ft per gallon) thickness and will still withstand extremes. That is the beauty of the EPDM polymer. A second coat would provide insurance where exposures are likely to be very extreme. Radical extremes in temperature where constant surface temperatures reach 250°F or above or -20°F or below. Warning, though, if the second coat is applied at the wrong time, it may create cracking, fissures or bubbling. The second coat should be applied either when the first coat is still tacky or when that first coat has had a chance to fully cure (up to 3 months.) https://youtube.com/v/ggLAUsiuI_o?version=3
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.
The video below is from a house near Charleston, South Carolina that I visited recently, and you'll see that the homeowner in this case didn't get his money's worth. I knew immediately when I walked into the attic that something was wrong because it was hot up there. In a properly insulated spray foam attic, the temperature won't be much higher than the house temperature.
25 years of field study and thousands of satisfied customers have made Liquid EPDM Rubber the roof repair solution for many applications. Liquid EPDM Rubber is so versatile that it can easily be applied to metal, rubber, fiberglass, concrete, wood, fabric, foam and many other surfaces. Liquid EPDM Rubber Coating has proven to outlast acrylic, urethane and elastomerics by 4 times. There may be lower-cost products on the market but none that have the long-term durability, waterproofing ability and tolerance to extreme temperatures like Liquid EPDM. Other roofing coatings require two and three coats so not only does this triple your material cost but also triples your labor time. If you are looking to add less weight to your roof with a one coat system that has proven itself over the years look no further. Here is a sample of some of the companies during that time who have come back time and time again!
I don't even want to ask this question but... several years ago we hired a local contractor to spray high density foam on the roof deck and walls of our unfinished 2nd floor. We realized that the job was done poorly and cut an access into the attic space to assess things. We realize now that they spray foamed directly to the chimney (no flashing). The chimney is currently used for a woodstove and DHW venting. The DHW will go away but wood stove will remain. My question is, how bad (unsafe) is this? I have found information on foam exposure to fire but have not been able to find anything about temperature ratings in general (i.e. what happens on prolonged exposure to high temperatures).
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.
I am an Architect in Toronto. I am designing a new roof addition to a row house building. Because of existing conditions and the shape of the new roof. It may be easiest to use closed cell spray foam within the areas of the joists. My question is when spray foam is used in this situation do I need to worry about how the joist members may be thermal bridges? It is not common to provide a little bit of rigid insulation to protect the joist members? The additional layer of outboard insulation will require an extra layer of plywood above the insulation which will add to cost.
Note: The practice of foam insulating the attic has raised eyebrows in the building industry because "standard" roofing techniques call for the attic to be ventilated; however, in a vented attic situation it will become approximately 130 degrees in the summer. There's no reason for an air-conditioning and vent-ductwork to have to work in that type of severe conditions. By applying Icynene right on the underside of the roof deck, the severe temperatures no longer exist in the attic. In short, the attic is now a "conditioned" space of the house that is just as comfortable as any other room in the home. This is called a "Compact Roof", which means you can frame right up against it. The one drawback of using expanded foam on the inside of the roof is that this will cause the temperature of the shingles to rise, but how much is not yet known. And how much damage a rise in temperatures could cause is debatable.
Although we are a small-town company, we can handle any size project or building. We have been blessed to work for residential homeowners as well as corporations like Bell Helicopter, Taco Bell, Tyson Foods, and even the Texas Rangers! Our conservative Christian family values won’t let us give you anything less than an honest evaluation of the best product for your specific application. SprayFoam Texas installs the most energy efficient attic systems available anywhere. https://m.youtube.com/e/ggLAUsiuI_o
You've got no argument from me there, Dennis. Getting a good installer if you're going with spray foam is crucial. Many builders or homeowners don't know how to find one, however, and that's where third party inspections come in. Also, even good installers have bad days, but if someone comes in behind them with a measuring probe and a Blower Door, there will be fewer sub-par foam jobs. http://www.youtube.com/embed/ggLAUsiuI_o
When looking for a long-term roof solution, compare apples to apples. Liquid EPDM Rubber is a one-coat application. There are no primers needed, and when you begin adding up the cost of other systems that require primers and multiple coats, you are often exceeding the cost of liquid EPDM Rubber and have an inferior sealant on your roof. Why add unnecessary weight to a roof by using multiple-coat systems? Cut your time and labor costs in half with a one-coat system. Liquid EPDM has a very thick honey-like consistency and a slow cure time. One of the biggest benefits of the product. During the cure process, you will see bubbles resembling those created when you cook a pancake. This is the catalyst at work forcing the trapped air to the surface. What you have after the cure is a chemical bond between your roof and the coating. No other coatings produces this result. Other products trap this air making future cracks inevitable as temperatures change or expansion and contraction of the roof occur.