R-value measures insulation's resistance to heat flow. It can also be referred to as "thermal resistance." The R-value of different insulating materials must be based on test methods established by the American Society of Testing and Materials (ASTM). Don't forget that R-values are determined by material type, thickness, and installed weight per square foot, not by thickness alone.
To the average person the higher the R-value number of your insulation, the warmer you should feel in the winter and cooler in the summer. The reality is something totally different as the R-value listed on insulation is not arrived at under real world conditions making them extremely misleading to the consumer. For instance,fiberglass insulation is generally assigned an R-value of approximately 3.5. It will only achieve that R-value if tested in an absolute zero wind and a zero moisture environment. Zero wind and zero moisture are not real-world. The average home with all its doors and windows closed has a combination of air leaks equal to the size of an open door, hence the reason why so many people feel that their homes are drafty. Even if you did a perfect job of installing Fiberglass or Cellulose insulation in your home and were to bring the air infiltration close to zero from one side of the wall to the other, you would still not stop air from moving vertically through fiber based insulation itself, in ceilings and walls. Water vapor from the atmosphere, showers, cooking, breathing, etc. constantly moves back and forth through walls and ceilings as well dropping Fiberglass or Celluloses insulation's R-value — as much as 50 percent or more as well.
By some estimates, 50-60% of your heat escapes through light fixtures, vents, and directly through your ceiling into the attic and out your ridge vent or soffits. This is why when considering insulation, addressing deficiencies in the attic can give you the biggest bang for your insulation dollar.
The only way to stop the moving of air and moisture within a building's structure is with an air and vapor barrier. One inch of spray Polyurethane foam insulation properly installed throughout the building structure can prevent more heat loss than all the fiber insulation that can be crammed into the structures walls.
Both Open-Cell and Closed-Cell spray Polyurethane foams are effective for reducing noise from outside sources by sealing cracks and gaps that allow sound to travel through the walls, floors and ceilings into the building. Of the two, Open-Cell foam has the best soundproofing capabilities.
Spray Polyurethane foam insulation is professionally installed at the same point in the construction cycle as other types of insulation. This typically occurs after the rough plumbing, electrical wiring, and heating and air conditioning ducts have been installed, but before the interior walls are completed in new home construction. In some cases spray Polyurethane foam insulation can also be applied in older homes, to the inside of roofs and under floors after construction has been completed.
Spray Polyurethane foam insulation is a two component, sprayed in place insulation designed to provide superior thermal performance on virtually any substrate (wood, masonry, metal studs and joists). When sprayed on the substrate, the foam expands allowing it to form a monolithic seal to the inside surface of exterior walls, to the underside of the roof deck, beneath floors, and in basements and crawl spaces. The result is that air can no longer penetrate your house making it less drafty and more comfortable.
Air leakage can also introduce moisture into the wall cavity, resulting in wet insulation and mold and mildew. With the sealing effects of spray Polyurethane foam insulation moisture can be reduced to the point that this will not be a concern.
If you are sealing the entire building envelope we always recommend some form of fresh air ventilation. Most building design professionals will advise you to seal the building structure as tight as possible and provide the necessary ventilation through an air exchanger attached to your heating and air conditioning system. In the winter, this simple machine brings cold fresh air from the outside and passes it by the warm stale air being expelled. This allows the fresh air to pick up the heat from the stale air, maintaining energy efficiency while providing a continuous supply of fresh air. In the summer, the opposite occurs giving the same results. In this manner, you can build an extremely energy efficient exterior shell using spray Polyurethane foam insulation while still providing controlled and energy efficient ventilation.
If you are retrofitting parts of your home, such as the attic, crawl space, or basement walls, you will probably not need to worry about your house being sealed too tightly as air enters the building envelope every time we open the door as well as through windows and locations within the home that typically are not reachable because of drywall etc.
Our position in regards to insulating a new home is that you will get only one chance to do the whole house. If you under-insulate you will regret it. In the unlikely event that you over-insulate the situation can be remedied with low cost ventilation systems as previously mentioned.
While typically 3-4 more times expensive than Fiberglass and blown-in Cellulose, spray Polyurethane foam insulation’s benefits allow it to provide a quick return on investment for the homeowner that continues indefinitely. Fiberglass in blown in form, batts and rolls, are not an air barrier and will not stop air leakage. Blown-in Cellulose will slow down air leakage but is also not truly an air barrier. Spray Polyurethane foam insulation will stop air leakage when sprayed to recommended thicknesses. Both Fiberglass and blown-in Cellulose have significantly lower R-values per inch of thickness than does spray Polyurethane foam insulation. Both Fiberglass and Cellulose can sag, settle, and shift over time leaving sections in the wall cavity and attic un-insulated or under-insulated. Spray Polyurethane foam insulation will completely adhere to the wood substrate and sheathing and is rigid; the result is a permanent barrier to heat loss and air entry that actually strengthens the structure. Fiberglass products and blown-in Cellulose will do neither.
Yes, the installed cost of spray Polyurethane foam insulation is somewhat higher than Fiberglass and blown-in Cellulose. However, the higher initial cost is partially offset because of the sustainability of the insulation (it will not degrade over time like fiberglass and cellulose) and you may be able to downsize your heating and air conditioning equipment. Additionally, you will save in your heating and cooling bills. Studies suggest that homes insulated with spray Polyurethane foam use up to 40 % less energy than homes insulated with conventional insulation. Your savings may be greater or less depending on your life style, appliances, house site, number and size of windows, etc.
Yes. The manufacturers of spray foam insulation do recommend that you leave your house or business for at least 24-48 hours to allow fumes to dissipate. We recommend that HVAC systems be turned off and that where possible windows or doors be left open. This will allow any fumes to dissipate at a quicker rate.
Closed-Cell spray Polyurethane foam insulation does not absorb moisture which is why we recommend it for below grade applications, attics, or anywhere in the house. Open-Cell spray Polyurethane foam, while an excellent insulation product, is susceptible to moisture which is why we do not recommend it for application in certain areas of the building structure.
Indefinitely. As an inert, long lasting polymer, any residential or commercial structure using spray Polyurethane foam insulation will retain its ability to reduce heat and cooling loss for years to come.
Spray Polyurethane foam insulation has the approval of all four major building codes in the United States, and Canada. Spray Polyurethane foam insulation is not only recognized as a Thermal Insulation, it also meets the requirements of a Vapor Barrier, and an Air Barrier. In fact, it is one of the most extensively tested insulation products ever.