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. https://youtube.com/e/ggLAUsiuI_o?app=desktop
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.
Repair and seal roof penetrations, tears, open seams, etc. using Elastek 103 Crack & Joint Sealant and reinforce with polyester roof fabric as necessary. In larger or deep ponding areas, apply Elastek 500 Puddle Plaster to fill in areas that hold water. Avoid using plastic roof cement. Serious ponding should be referred to a roofing contractor. Blisters in previous coatings may be opened but these areas must be allowed to dry-out completely. Blisters in the roofing ply should be left alone unless likely to break. Caulk and reinforce open seams, roof penetrations, cracks, and tears. These are potential leak points so work carefully and thoroughly. Use fabric to build flashings around roof edges or roof penetrations, and to reinforce various coating repairs. A polyester fabric is used because it will stretch with the coatings. (Fiberglas fabric is not recommended.) Fabric is normally cut to extend three inches beyond the repaired area in all directions. The coating is applied to the roof surface and the fabric is immediately pushed into the wet surface. An additional coat is applied over the fabric and the patch is allowed to dry. If your roof has stucco parapets, examine them for cracks along the sides and top. These areas often permit water to enter the wall and can cause blisters and wrinkles in the roof surface. Repair with Elastek 103 Crack & Joint Sealant. If you do not have parapets, examine the metal drip edge for a tight seal with the roof membrane. Use 4″ or 6″ roofing fabric covered under and over with Crack & Joint Sealant to seal cracks along drip edges, penetrations, and open seams. https://m.youtube.com/watch?feature=player_embedded&v=ggLAUsiuI_o
Q. "I talked to a building product supplier for WALLTITE spray foam, he is suggesting to use 2" or 3" of closed cell-spray foam in the joists areas instead of the batts insulation. He says it will work with outboard rigid insulation. There is a location of a cantilevered floor area with steel beam so I may need to use spray foam to protect the steel beam. It would then be convenient continue to spray in the floor joist cavities and then apply 5" of polyiso outboard of the bottom cantilever floor sheathing."
I did a LOT of prep before using this product. Cleaned, vacuumed, installed additional insulation etc etc etc. This spray foam was easy to work with, and did it's job as it was supposed to. If you are curious, this kit was purchased because - every "foam insulation company" I contacted either did not call back (due to no interest) OR this was too small of a job. That is why I went DIY on this one, that and: I was advised by one of these companies that they have a minimum $2k job because ... (insert your answer here, but I will choose that everyone needs to eat).
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.
OK, Peter, I finally went back and read Alex Wilson's article on what he perceives as a serious problem. I haven't seen the full report, but based on the summary he wrote on the Green Building Advisor website, I question the science. It seems to me that he's chosen the wrong metric and he's basing his conclusion on too many assumptions because he doesn't have enough data. You can see my comments at the end of his article. http://youtube.com/watch?feature=youtube_gdata&v=ggLAUsiuI_o
Spray foam insulation, like other insulation, saves on energy costs and lowers utility bills. Studies by the US Department of Energy show that 40% of a home's energy is lost as the result of air infiltration through walls, windows and doorways. Buildings treated with spray foam insulation insulate as much as 50% better than traditional insulation products.
I live in Baton Rouge LA with a very old and drafty house. There is no blockages in the walls between the crawl space and attic. Lots of critters just come on in. I would like to used closed cell sprayed under house to warm up floors and block moisture. I would like to spray closed cell into attic, but am afraid of enclosing attic due to moisture build-up. Can I spray closed cell against the attic floor in same way as installing bats, thus leaving my venting the same as it always has been. Other ideas? Thanks.
This high R-value of 4.45 at 1 inch, polyurethane insulation expands to seal cracks, gaps, and voids in attics, walls, crawl spaces, and ceilings. Agribalance is a three-quarter pound density foam that reduces air leakage by improving energy efficiency, and reducing moisture intrusion and outside contaminants such as dust, dirt, and allergens. As a result, builders can generally install smaller, more energy-efficient HVAC systems and achieve similar, or superior comfort compared to traditionally insulated structures which require a larger, less efficient HVAC system – resulting in higher energy costs.
In the case you have above the installer wasn't reading his foam. They must be trained to do that as they spray. Temps and conditions are constantly changing thru out the day. Either he wasn't properly trained or if he was,he wasn't doing his job! This is a serious problem with people jumping in to the foam business. A lot of homeowners and builders are looking the best price and end up with someone who doesn't know what they are doing. Hope this info helps. Foam insulation is a great product. It just has to be done right by someone who knows what they are doing.
Spray Foam Sealant
Some states, municipalities and utilities have programs. Check with your coatings manufacturer for further information. As a membership benefit, RCMA provides maintains a database of current information on rebates and tax credits for installing reflective roofs. RCMA’s customized search tool can be used to find the most up-to-date listings of reflective roofing financial incentives available.