Originally posted 2010-12-23 06:26:49. Republished by Blog Post Promoter
The purpose of insulation, though, is to slow down the movement of heat through your walls. The insulation doesn’t care which way the heat is moving, so it does just as good a job keeping the summer heat out as it does the winter heat in.
Fiberglass batts are the cheapest, easiest way to insulate new walls. However, they’re often installed poorly â€” and even small gaps can reduce efficiency as much as 25 percent.
This is where fiberglass insulation comes in handy. Fiberglass insulation is made from very fine strands of glass held together in a thick, random mat. Between the fibers are many small pockets of air.
The glass strands themselves are very poor conductors of heat. In order for heat to be transfered through the mat, then, it must be carried convectively through the tiny air pockets. But the randomness of the strands means there is no direct path through the mat, so the heated air must take a very circuitous route through the wall.
Remember not to fold or compress your insulation. This will remove the air pockets and increase the rate of heat loss by conduction. Also try not to install the batts or cut pieces sideways where your fibers are all connected and running in lengths, this will also affect the R value of your insulation.
Cut slits in the batt so that it fits snugly around any obstructions in the wall, like plumbing pipes and electrical wires. When insulation is stuffed into a cavity that has obstructions, gaps are created behind the pipes or wiring and can reduce the R-value of the insulation.
When your insulation installation is complete it is time to add your vapour <a href="http://www.barriehomeinspector.com”target=”_blank”rel=”external”title=”Barrie Home Inspector” >barrier. 6mm poly is required by the building code and should be secured around all edges with Tuck tape if possible. Many builders only staple the vapour barrier in place where Tuck tape will seal all edges. The purpose of the vapour barrier is to prevent the moisture in the air, humidity, moving through your insulation. If the moisture is allowed to move through the insulation it will condensate into water part way through your insulation where ever it meets the Dew Point. The Dew Point is the temperature that humidity turns into condensate.