Specifications

2008 Residential Appendices RA3-27
Appendix RA3 – Residential Field Verification and Diagnostic Test Protocols
RA3.5 High Quality Insulation Installation Procedures
RA3.5.1 Purpose and Scope
RA3.5 is a procedure for verifying the quality of insulation installation in low-rise residential buildings. A
compliance credit is offered when this procedure is followed by the insulation installer and a qualified
HERS rater. The procedure and credit applies to wood framed construction with wall stud cavities,
ceilings, and roof assemblies insulated with mineral fiber or cellulose insulation in low-rise residential
buildings.
The procedure for verifying the quality of closed-cell spray polyurethane foam (SPF) insulation
installation is outlined Joint Appendix JA7.
RA3.5.2 Terminology
Air Barrie
r An air barrier is needed in all thermal envelope assemblies to prevent air movement.
Insulation, other than foam, is not designed to stop air movement. For insulation installed
horizontally, such as in an attic, the insulation must be in substantial contact with the
assembly air barrier (usually the ceiling drywall) on one side for it to perform at its rated R-
value. A wall or ceiling covering that has multiple leakage sites (such as 1 x 6 tongue and
groove board ceilings) can not serve as an air barrier.
Air-tight Thermal envelope assemblies (such as wall assemblies) shall be built to minimize air
movement. Air movement can move unwanted heat and moisture through or into the
assembly. For these procedures air-tight shall be defined as an assembly or air barrier
with all openings greater than 1/8 inch caulked, or sealed with expansive or minimally
expansive foam.
Excessive
Compression
Batt insulation may be compressed up to 50 percent at obstructions such as plumbing
vents and in non-standard cavities, but compression of more than 50 percent in any
dimension is excessive and shall not be allowed. Where obstructions would cause the
insulation to be compressed greater than 50 percent insulation shall be cut to fit around
the obstruction.
Delaminated Batts are often split or delaminated to fit around an obstruction. For example when an
electrical wire runs through a wall cavity the insulation must still fill the area both in front of
the wire and the area behind the wire. This is typically accomplished by delaminating the
batt from one end and placing one side of the batt behind the wire and the other in front of
the wire. The location of the delamination must coincide with the location of the
obstruction. For example if the wire is one third of the distance from the front of the cavity
the batt should be delaminated so that two thirds of the batt goes behind the wire and one
third in front of the wire.
Draft Stops Draft stops are installed to prevent air movement between wall cavities, other interstitial
cavities - and the attic. They are typically constructed of dimensional lumber blocking,
drywall or plywood. Draft stops become part of the attic air barrier and shall be air-tight.
Fire blocks constructed of porous insulation materials cannot serve as draft stops since
they are not air-tight.
Friction Fit Friction fit batts are commonly used. Friction fit batts have enough side-to-side frictional
force to hold the batt in place without any other means of attachment.
Gaps A gap is an uninsulated area at the edge of or between batts. Gaps in insulation are
avoidable and are not permitted.
Hard Covers Hard covers shall be installed above areas where there is a drop ceiling. For example a
home with 10 ft ceilings may have an entry closet with a ceiling lowered to 8 ft. A hard