Building Codes throughout North America
require that air leakage into your attic be limited and controlled. Air leakage takes heat and moisture with it - wasting
energy and leading to potentially serious moisture problems.
Energy Codes in force across North America require that attic
access openings be caulked, gasketed, weatherstripped, or otherwise sealed to limit infiltration and exfiltration. This is
because air leakage through cracks can result in higher energy use for home heating and cooling
than necessary.
The 2000 International Energy Conservation
Code (IECC™) - is the latest version of the Model Energy Codes. It has been adopted
either state-wide or in municipalities in 26 states, and specifies that all
penetrations in the building envelope between conditioned and unconditioned space that are sources of air leakage (attic
access panels are specifically mentioned) must be sealed with durable caulking materials, closed with gasketing
systems, weatherstripping or otherwise sealed to limit uncontrolled air movement (see IECC Sections 502.1.4.2 and 602.1.10).
Nearly
all of the 50 states (as well as our territories) have adopted an Energy Code either the same as or based on a Model
Energy Code. Model Energy Codes commonly used are the 2000 and 1998 IECC, or the 1992, 1993 and/or 1995 Model Energy
Codes (MEC).
According to the "Plan Check & Field Inspection Guide for 1992 MEC, 1993 MEC, and 1995 MEC", as well as
the "Plan Check & Field Inspection Guide for 1998 IECC and 2000 IECC", inspectors are instructed to verify that all doors between conditioned and unconditioned spaces have door boots and weatherstripping.
Weather stripping must be installed around attic and crawlspace access panels if the panels are located in a conditioned
room.
When inspecting for the Residential Provisions of the IECC/MEC, Building Inspectors are taught that proper
air sealing will not only decrease the energy use of the building, but it will also increase the comfort of the homeowner
and the durability of the home. Air leaking into and out of the wall, ceiling, and floor systems can carry water vapor that
will condense within the framing cavities. Air movement carries significantly more moisture than vapor diffusion. This condensed
water can then cause mold growth and rot within the cavities, shortening the life span of the structure.
Building Inspectors are also taught that all penetrations in the
building envelope between conditioned and unconditioned space must be sealed with durable caulking materials or closed
with gasketing materials. To spot a potential air leakage site, look along cracks in the building envelope for light. If you
see light, you have an air leak. There are several places where air leakage can occur, including
the attic stairway panel. (see "Inspecting for the Residential Provisions
of the IECC" - page 9).
In Massachusetts, (and
numerous other states and municipalities), the State Energy Code requires that "access
doors, hatches, scuttles, pull down staircases and similar constructions that are part of the building
envelope shall be insulated to a level equivalent to the insulation of the surrounding
floor, wall, and ceiling." - (see ENERGY CONSERVATION FOR NEW CONSTRUCTION LOW-RISE RESIDENTIAL BUILDINGS (780 CMR Appendix
J), section J4.2.5).
Below
are quotes from several Building Code Inspection Guides - the full text of which can be downloaded
from our WEATHERIZATION LINKS page:
-
From Plan Check & Field Inspection Guide for 1992 MEC, 1993 MEC, and 1995 MEC, as well as the Plan Check
& Field Inspection Guide for 1998 IECC and 2000 IECC
"Weather stripping must be installed
around attic and crawlspace access panels if the panels are located in a conditioned room".
"Air leaking into
and out of the wall, ceiling, and floor systems can carry water vapor that will condense within the framing cavities. Air
movement carries significantly more moisture than vapor diffusion. This condensed water can then cause mold growth and rot
within the cavities, shortening the life span of the structure."
"To spot a potential
air leakage site, look along cracks in the building envelope for daylight. If you can see daylight, you have an air leak."
"There are several
places where an air leakage can occur... At the attic and crawlspace panels".
"Fiberglass batt
insulation is not an effective air sealant. Caulking and weatherstripping must be installed in accordance with the manufactuer's
installation requirements."