Floor Joist Headers
This section discusses
Why you
should be concerned over the quality of the insulation and AVB in the floor joist
header area
When compared to the rest
of the building envelope, installing effective insulation and air / vapour barrier
(AVB) in the floor joist header area often requires additional time and effort.
Because of this, many builders perform a less than adequate job in this area.
The hidden cost of a poor
insulation and AVB installation will hit you both through increased heating bills
and, in many cases, a wet basement floor in the springtime.
How
heat energy is lost through the floor joist header area portion of your building
envelope
 Because
of the stack effect, in Manitoba winters the main floor joist header area is most
always subject to cold, dry air infiltration. Stack effect describes the way warm
air naturally rises and leaves the upper portions of a house and is replaced by
cold air coming in at the lower levels. This inward movement of cold exterior
air through the header area causes the furnace to cycle more often and increases
heating bills.
In addition, a poorly sealed
header air barrier will also allow warm moisture-laden interior air to find its
way back behind the framed wall and insulation, come in contact with the cold
concrete foundation to condense, and form frost. This frost will build up slowly
over the winter and come the first warm day in spring, melt, and run out as moisture
on your basement floor.
|
