Spray Foam Insulation

2012 to 2017 Consumer Choice Award Winner for Insulation Contractor

The Best Way to Insulate Walls


 

Spray Foam Insulation comes in many densities, 0.5 to 3.0 pounds and even higher. The 3 pound density foam is used in our SPF Cool Roof System.

Two pound density foam is what we recommended for all exterior walls. It is good and strong; it's an air barrier at 1 inch and a vapor barrier at 2 inches. It can be sprayed directly to any surface such as wood, brick, concrete, drywall, metals (galvanized steel requires at primer)

The number one thing you as a building owner want to accomplish as it relates to insulation is to stop the conditioned air inside your home from leaving through ways you can't control. There's a number of ways that paid for conditioned air leaves your building. Through air infiltration by cracks and gaps and through two other processes known as Conductive Heat Transfer and Convection Currents.

Air Infiltration

Air leakage accounts for 25-40% of the energy used for heating and cooling in a typical home or building. That's the equivalent of always leaving a window open, allowing conditioned air to leave your home and unconditioned air and moisture to enter it through gaps, cracks and holes in the building envelope. At one inch spray foam insulation is a air barrier, with all air infiltration points completely sealed off a dramatic drop in heat loss be achieved.

Airliners fly at 36,000 ft and minus 70 degrees Celsius outside with only two inch thick walls, how do they keep passengers comfortable with little effort? The answer is simple, the jet is completely air sealed. When you air seal a airliner or building you need less insulation.

Conductive and Convective Heat Transfer

Conduction is a method that heat uses to migrate through the ceiling, floors and walls of a structure. An example of which is the heat felt in the handle of your pot after boiling water. Conductive heat transfer is relatively slow.

Convection is the transfer of heat by liquid or gas molecules moving from hot areas to cold areas (a temperature gradient). When two fluids of differing characteristics come into contact, convective currents are formed to equalize the differences, transferring heat energy from warm areas to cold areas. This method of heat transfer is relatively fast and accounts for 80% of heat loss while only 20% of heat loss is due to conduction.

Fiber Insulations slow convection. Spray Foam Insulation STOPS convection




How does Moisture Become a Problem?

When air travels through a building wall, it takes with it not only heat, but also water vapor, pollutants, dust, odors and, allergens. In order to prevent moisture from entering unchecked, a wall system must stop the movement of air across its components. In houses, even fairly small air leaks can move large amounts of water vapor compared to vapor diffusion. Some experts estimate that the ratio of moisture transported by air flow compared to vapor diffusion is 10 to 1 or higher. The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) 2001 Fundamentals recognizes that effectively controlling moisture in a home requires an effective air barrier and states that "without effective control of airflow, vapor barriers are completely ineffective."



R-Value vs Temperature

There is a problem with fiberglass insulation in cold climates. It appears that, as temperature drops below a certain point, air begins to circulate into and within the insulation, forming "convective loops" that increase heat loss and decrease the effective R-value. At very cold temperatures (-20F), the R-value may decrease by up to 50%."

In full-scale attic tests at Oak Ridge national Laboratory, the R-value of 6 inches of cubed loose-fill attic insulation progressively fell as the attic air temperature dropped. At -18 F, the R-value measured only R-9. The problem seems to occur with any low-density, loose-fill fibrous insulation.(J.D. Ned Nisson, "Attic Insulation Problems In Cold Climates")




The Best Solution

Placing just 2 inches of spray foam insulation directly will stop heat loss by 90% and 95% at 3 inches especially when compared to other insulation types such as fiberglass or cellulose which can only slow this process.