Closed-cell (aka two-pound foam) is denser than open-cell at about 2 pounds per cubic foot. Its R-Value is between 6-6.5 per inch. As a result, this kind of foam is much more expensive than its counterpart. The reason closed-cell doesn't need a vapor retarder is because it already has one. It's permeance is 0.8 perm, which means it can handle cold climates without the use of an additional board or drywall. Closed-cell uses hydroflurocarbons (HFCs) as part of its makeup. However, this material has been known to have a high global warming effect. If you want a green insulation solution, this is not the material to use. A way to avoid this and still use closed-cell is by installing it alongside fiberglass batts.
Sta-Kool 780 Siliconized Acrylic White Elastomeric Roof Coating Sta-Kool 780 Siliconized Acrylic White Elastomeric Roof Coating is a high quality flexible white acrylic roof coating. Product is enhanced with silicone for improved water resistance adhesion and life expectancy. Product resists cracking peeling while offering tremendous durability and long term life. The coating forms a durable protective barrier which ...  More + Product Details Close
You probably have some familiarity with spray foam insulation, and you may have even used the foam that comes in pressured spray cans at home improvement retailers. This foam is know as one-part foam, meaning that it is one continuous mixture that is simply applied to the area in need. One-part foam is frequently used for sealing small gaps and cracks.
Roof coatings made with acrylics, urethanes or asphalt soften under the stress of ponding water or snowpack. Eventually, these roof coatings will bubble and peel away from the substrate, leaving your roof vulnerable to leaks, rot, and decay. However, GacoRoof’s 100% silicone formulation is designed to stand up to whatever the elements dish out. Silicone will withstand areas of ponding water without softening, bubbling or peeling from the substrate. Acrylic, urethane and asphalt roof coatings decompose and wear away from the stress of harsh sunlight, UV rays, and freeze-thaw cycles.

How Much To Spray Foam Crawl Space

This is more common with closed cell foam, but it happens with open cell foam, too. Since closed cell foam has a higher R-value per inch, installers generally spray 2" in walls and 3" in rooflines to meet the energy code requirements of R-13 and R-19, respectively. (I'm not going to dive into the energy code here, but these numbers apply to many climate zones, the latter being allowed under the UA tradeoffs rule. See the Energy Nerd's blog on this topic if you want to argue.)
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.
The problem you saw with the closed cell foam pulling away like that is due to the heat of the foam was to hot. It was actually curing out and making foam before it could adhere to the wood. The installer wasn't reading his foam correctly. He should of stopped and turned down the heat on his hose temp. Also installers have to be aware that as the sun rises and the temp in attics rises the subtrates get hotter as well. This will cause the installer to adjust his heat when installing the foam as the temp changes thru out the day.  
As mentioned above elastomeric coatings can be used to fix almost all types of roofs. Examples of common roof types that will work well with elastomeric coatings include; wood, polyurethane foam, single-ply roofing, modified bitumen, metal roofs, concrete and built-up roofing. If you aren't sure your roof type will work well elastomeric coatings, do not hesitate to contact us. Our experts are always willing to help.
The local foam installer that I used here in Hilton Head told me he looked for some peeling back of the foam. This was ensuring that it was at the perfect temperature which helped them maximize their yield (profit). I have open cell foam and it pulled away a little, and did so immediately (within minutes). They went back after they were done to any spots that pulled away too much and filled them with the touch up kit; they were looking for the top edge to roll just a little bit.
Spray foam insulation is a great product. Homes insulated with it can be some of the most efficient and comfortable homes built. I've been in plenty of these homes and can tell you that when spray foam is installed properly, they outperform 99% of fiberglass batt-insulated, stick-built homes. (I can also tell you that 73% of all statistics are made up on the spot, so please don't ask for documentation of that statistic.)
NOVA Spray foam did just as they promised and, more importantly, for the price they quoted. The two employees who ultimately installed the product were very nice, pleasant, and respectful. Bottom line: We are delighted with the install. Our house now holds a more stable temperature and no longer has hot spots. It used to be very difficult to cool our upstairs bedrooms; those days are gone! Pocketbook issues: For the last three billing cycles we have used approximately one third less electricity as the AC does not come on as often. Would we do this again? Yup! Do we recommend this installer? Yup! Do the neighbors think it’s cool? Yup!

While coatings may potentially stop minor leaks, the roof should be properly repaired and dried prior to coating application. Coatings may be able to seal pinhole leaks, which are leaks not visible to the naked eye. If the roof is leaking, the roof leak will need to be identified and repaired prior to any recoating; do not expect the coating to find and seal the leaks.
Spray foam insulation, when properly installed is both an air barrier and when closed cell foam is used at the proper depth a vapor barrier!  Before hiring any contractor you should establish the brand of foam being used and verify that with the named manufacture.  Please ask for ESR reports and MSDS sheets on any foam being installed in your home. A couple areas where you might consider spray foam insulation include:

I have been looking to have closed cell insulation added through out my attic space. I cant seam to find a installed that wants to install no more than 2 inches, and thats not near my R-valve for South Carolina (Lake Greenwood)please send any advice that will help me to see what installer will perform the correct job. This is a expense that i can only afford to do once. Sandi

You probably have some familiarity with spray foam insulation, and you may have even used the foam that comes in pressured spray cans at home improvement retailers. This foam is know as one-part foam, meaning that it is one continuous mixture that is simply applied to the area in need. One-part foam is frequently used for sealing small gaps and cracks.

I just received this and it worked well for me. It works well for small gaps (around windows, between studs), but probably not the right tool for larger gaps (>1" or 2"). If used in larger gaps, it works OK if it is layered in. Spray a little and wait for it to set, then layer another on top, etc... This is pretty much noted by the seller. It is pretty much exactly as described and priced right, so 5 stars. If you need to do larger gaps, buy 2 part.
Acrylic coatings are typically applied in two coats, with the second running perpendicular to the first. 1 gallon per 100 square feet is a good estimate for these coatings, as they do not need to be applied nearly as thick as many other coatings. These coatings can be sprayed or roll-applied. Acrylic coatings generally require a re-coat within 2-3 years of application.
Starting a new build (1 1/2 basement walkout), all 2x6 exterior walls w/ brick veneer in CZ3. Above grade, would like to do spray foam in 2x6 walls, 1/2" or 1" of rigid foam board on the exterior, and a 1" air gap. Will this require a house wrap or can I do w/o the rigid foam and go with a housewrap? Also, any recommendations about insulation strategies for the finished basement. Thanks!

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