There is a significant price difference when it comes to using foam insulation to insulate a new versus older home. Spraying insulation inside a newly constructed home is easier because the installation company can ensure the insulation will work effectively and design it for optimum defense against sound, heat transfer and utility costs. Installing spray foam in older homes that contain existing insulation can cost additional time and money -- it is not usually recommended as compared to weatherization or an energy aduit.
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.
Spray Foam Roof Insulation
Silicone coatings are typically produced by adding a catalyst and solvents to a silicone base. Because the silicone is a natural material, these coatings are bio-degradable. They can be applied to a roofing system using many different techniques, including spraying or rolling. Silicone coatings are available in many colors, including reflective white and translucent.
For large jobs, professionals such as Dr. Energy Saver use two-part foam, which comes in larger containers. With 2-part spray foam, it's necessary to mix separate resin and catalyst compounds at the application nozzle. Combining these ingredients starts a chemical reaction that creates expanding foam. Contractors use small 2-part foam "kits" to air-seal an attic or to seal and insulate ductwork. To insulate an entire attic or wood-framed wall with spray foam, the resin and catalyst compounds are pumped to the application nozzle from 50-gallon drums in a specially equipped truck. https://www.youtube.com/watch?v=ggLAUsiuI_o&feature=youtu.be
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.
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.
Sta-Kool 800 15-year White Elastomeric Roof Coating is Sta-Kool 800 15-year White Elastomeric Roof Coating is a high quality very flexible white acrylic latex roof coating. Coverage is 50-75 sq. ft. per gallon per coat. Two coatings are recommended. This performance product resists cracking and peeling while offering tremendous durability. This long lasting formula forms and excellent highly ... More + Product Details Close https://www.youtube.com/watch?v=ggLAUsiuI_o&feature=youtube_gdata
We have a 1950's ranch in Atlanta and are interviewing foam contractors to spray open cell under the roof, with an "ankle wall" out towards the eaves to seal the attic. My wife and daughters are chemically sensitive, so I'm trying to figure out how to minimize the fumes coming into the house. Additionally, at least one contractor has offered (for > $900) to remove our existing rock wool & R-13 fibreglass from the attic floor to "increase cross-ventilation into the attic". Seems to me I can't both minimize fumes AND increase cross-ventilation. They also offered to spray a fire-retardant on for >$600. Would ventilation during installation help any or woud the retardant seal off the foam and help that way? Thanks...
Most flat roofs are not perfectly sloped, causing water to puddle in some areas, in particular around the drains and scuppers. Many roof coatings are not rated or warranted for "ponding water", and thus might fail pre-maturely if exposed to standing water over long periods of time. Serious consideration should be given to the performance and limitations of the coating being selected. Some manufacturers will warranty their coatings including ponding water. Typically, manufacturers for acrylic roof coatings do not include warranties for ponding water, while some polyurethane and silicone roof coatings manufacturers will.