Insulation
Why:
The objective of insulation is to seal conditioned areas from air penetration,
reduce heat transfer (R-value), and keep moisture out. In other words: insulation
is needed to keep conditioned areas separated from unconditioned areas. It is
important to insulate well (picture right), in cold and warm climates.
How:
The building envelope is made up in to two layers:
1--The air barrier is made up of drywall and sheathing, to stop air
leaks. It also keeps moist air from penetrating into insulation material,
which can dramatically reduce the R-value, damage the building materials, create
mold, and affect the health of the inhabitants
2--The insulation barrier is made up of insulation material (batts
or loose fill) that insulates against heat transfer, but does NOT
seal against air leakage.
Moisture will dramatically reduce the R-value (insulation capacity/value/rating)
of any insulation material.
To protect against rain or moisture, a continuous vapor barrier
should be properly installed within the wall system of the home. Have a well-functioning
drain system between the inside and outside wall, and around the house have
a well-functioning (French) drain system and a sloping ground to keep the rain
away from the foundation and walls. Also, have a sill gasket on top of the foundation
wall to prevent moisture from wicking into the framed wall from the concrete
foundation via capillary action.
Where:
Insulation is needed at the thermal boundaries of the building envelope, including
between framing members, called bridging. Areas that need insulation are:
-Walls
-Attics
-Ducts
-Windows
-Foundation