To avoid the expense re-roofing a house that is simply suffering from nail fatigue, and to obtain optimum insulation, an 85mm layer of polyurethane foam can be sprayed onto the underside of the slates or tiles of a pitched roof. This stabilises and weatherproofs the roof by fixing the nails, battens and roofing felt. As the foam is a superior insulant, coupled with just 100mm of insulation at joist level, your roof will also meet the stringent thermal performance standards required for a new home. A typical roof can be insulated using the polyurethane treatment for around half the cost of re-roofing.
Current guidelines recommend up to 10 inches of insulation in your attic . This is usually added to the ground, rather than the roof line, which results in the loss of your storage area, due to not being able to refit floor boards after installation. By implementing spray foam insulation to the roof line, you regain the lost 10 inches, thus increasing storage, height and practicality.
One thing I wanted to mention was that I think your price point is a little high and that might deter people from considering spray foam. As a project manager for a spray foam company for years I can tell you that we offer 0.5 Lb. open-cell foam at around $.25/board foot. We even offer a 1.0 Lb. open-cell foam for less/the same cost as you quoted the 0.5 Lb. foam for above. The 1/0 Lb. open-cell foam has an R-value of almost 5.
If you’re looking for an effective and efficient Elastomeric Roof Coating, you might want to consider the Kool Seal roof coating. This product comes in a 115 fl oz container and is white in color. It is easy to apply and use that it can stick well even in the harshest weather conditions. This product offers maximum clinging to the RV roof despite the temperature. You can also rely on its effectiveness no matter the type of weather.
Spray foam insulation systems effectively seal walls, roofs, corners and other surfaces, creating a more comfortable household because it provides a barrier against drafts and associated pollen and dust. Long-term, properly installed spray foam won’t change its form or shape, meaning it will deliver the same benefits that it did years—or even decades—after being installed, while other insulation materials may settle and create future gaps in the insulation.
I've seen this only once, and it was with closed cell foam, but I've heard of it happening with open cell foam, too. I don't know the details, but I've heard it could result from a bad batch of chemicals, improper mixing, or too high a temperature. Whatever the cause, it's not a good thing. The photo below shows how the spray foam pulled away from the studs. A little bit of uninsulated area like that adds up to a lot of heat loss/gain when the whole house has that problem, as it did here.
Light-density open-cell SPF is commonly known as half-pound foam. It is a semi-rigid material with a sponge-like appearance that expands during installation and creates small, open cells that are filled with carbon dioxide. Due to its ability to expand during the application process, it fills cracks, crevices and voids and adheres to irregular surfaces or substrates to form an air sealing insulation.
Allison--would be very interested in your take on the GHG issues of foams, which have received lots of smart commentary recently. To highlight a few: architect Jesse Thompson's comments on Tom's Good vs Bad post on Energy Circle, the very thorough piece by Alex Wilson on Green Building Advisor and Michael Anschel's cautionary diatribe on Remodeling. https://www.youtube.com/watch?v=ggLAUsiuI_o&feature=share
Spray foam insulation or spray polyurethane foam (SPF) is an alternative to traditional building insulation such as fiberglass. A two-component mixture composed of isocyanate and polyol resin comes together at the tip of a gun, and forms an expanding foam that is sprayed onto roof tiles, concrete slabs, into wall cavities, or through holes drilled in into a cavity of a finished wall. https://youtube.com/embed/ggLAUsiuI_o
Both high and low-pressure, two-component spray foam are applied by professional contractors who are trained to use and apply SPF with the required equipment (protective gear, full eye protection, respirators, and gloves). Contractors should follow the ventilation recommendations by the product manufacturer to avoid overexposure through inhalation, and instruct those without protective gear (homeowners or building occupants) to stay away from the work area during exposure times and to not return until instructed by the professional contractor.
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.
Spray Foam Professionals
Closed-cell foam has a higher density and offers a higher R-value per inch. It also adds strength to walls, ceilings and roofs and can contribute to a structure’s overall durability. Additionally, closed-cell foam’s low water vapor permeability offers protection from moisture when installed in places where high humidity—from climate, occupants, or flooding—meets the structure.
Roof coatings can add 25 years to the service life of a roof and reduce the amount of discarded roofing materials that end up in landfills. The infrared image on the right shows 175 °F (79 °C) on the uncoated (black) section of the modified bitumen roof. The coated (white) section is 79 °F (26 °C). Field studies have shown that cool roof coatings can lower rooftop temperatures and reduce air conditioning bills.