DID YOU KNOW? Spray FOam insulation out-performs conventional insulation materials because they (conventional insulation materials) trap still-dry air and if that air moves or becomes wet, the thermal resistance can drop by 50%. Spray Foam protects against air infiltration, which can increase energy costs in buildings by 10 to 40%. Eliminate these drafts and live in a more energy-efficient, comfortable and healthier building by choosing spray foam insulation.
Low-density foam is applied as low or high-pressure, two-component polyurethane spray foam. Low-density spray foam can be applied on walls, in unvented attics, to ducts and ceilings, and in vented attics and crawl spaces. It is known as an air barrier, but permeable to vapor and moisture. It is often used to fill cavities in walls during construction.
If you cut the nails holding one of the corner studs to the bottom plate and the top plate with a Sawzall, you can use a flat bar (or a flat bar plus a wrecking bar) to pull the stud off the sheathing nails. Either re-use the stud, or buy a new stud, and install the stud with toenails as shown in the link I provided in Comment #51 (this link: Outside corner detail).
Sporadic cases of hypersensitivity pneumonitis (HP) have also been reported in workers exposed to isocyanates. The symptoms may seem like the flu, with fever, muscle aches, and headaches. Other symptoms may include a dry cough, chest tightness, and difficult breathing. Individuals with chronic HP often experience progressively more difficult breathing, fatigue, and weight loss. Individuals with acute HP typically develop symptoms 4–6 hours after exposure.
Spray foam insulation, also known as foaming insulation or sprayed insulation, is a two-part liquid insulation material that insulates and air seals wherever it is applied. The material comes in two large 55 gallon drums – an iso and a resin. These two liquids are kept separate until applied at the jobsite by a qualified, licensed spray foam installer. The two liquids travel up through a heated hose to the spray gun where they are combined to create the foam. The foam expands within seconds to fill the cavity surface. Depending on the type of sprayed-in foam insulation used, closed-cell or open-cell, the foam expands between 40 and 100 times its size upon application.
R-value, the thermal resistance measure of insulation, varies between all insulation products whether they are fiberglass, cellulose, open-cell spray foam insulation or closed-cell sprayed-in foam insulation. Generally speaking the rule of thumb is the higher the R-value, the greater the insulating power. Focusing on spray foam insulation materials, there is a difference between the two main types. According to industry publication, Fine Home Building, the R-value for open-cell spray foam is between R-3.5 – R-3.6 per inch. However, there are open-cell spray foam insulation products actually offer R-3.7 per inch such as Icynene Classic and Icynene Classic Max. The open cell structure of low density foam insulation means the R-value is lower than its closed-cell counterpart. Nevertheless, open-cell spray foam does offer superior and consistent thermal insulation and air sealing properties.
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.
According to the Department of Energy, an estimated 20 to 40 percent of a home’s utility bill could be going to waste from drafts and air leaks around openings. As temperatures cool and energy costs rise, the positive impact of energy efficiency on a building comes into focus. Air can enter and escape a structure through every gap, compromising the building envelope. Adding the right insulation and air-sealing will close these gaps, keeping interior spaces comfortable and reducing energy bills. http://www.youtube.com/e/ggLAUsiuI_o
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.
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:
Foam is very sticky; you'll need to wear disposable coveralls with a hood, and gloves, a face mask, and eye protection. It takes some practice to spray foam evenly and, because it expands so dramatically, to control its depth; 2 inches is all you need to seal the joist cavities. You need a clear area so that you can work without interruption; any pause longer than 30 seconds will clog the nozzle and require putting on a new one. It's also critical that the air temperature stays between 75 and 85 degrees.
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.