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Insulation Standards
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PROCEDURES FOR PROPER INSTALLATION OF INSULATION
The purpose of envelope insulation is to provide a continuous thermal barrier to minimize heat flow through the walls, ceiling and floor. Insulation serves to keep a home comfortable and reduce costs for heating and cooling. The home will not be as comfortable and energy costs will be increased if insufficient insulation is installed, or it is installed incorrectly, such as being compressed or installed with gaps. Furthermore, it is not difficult to install insulation correctly.
Background: Recent studies have found that over a third of new homes have lower levels of insulation installed than specified and an additional fifth have serious installation problems that will result in significantly decreased effectiveness of the insulation. In addition, virtually all of the homes studied were found to have numerous insulation installation defects that reduce the performance of the insulation well below its rated R-value. All of these can lead to defect litigation. These cost-effective procedures will improve comfort, reduce energy use, and reduce potential defect liability exposure.
Use of these Procedures: The purpose of this document is to provide the tools to ensure insulation is properly specified and installed, resulting in a comfortable, energy-efficient home.
Builder: Include these materials in your bidding and contracting documents. It is meant to form the basis of a scope of work for both bidding and contracting. Its use will help ensure consistent bids and quality installations. Attachment I-1 and I-2 are to be followed by the insulation contractors. Attachment I-2 is an installation checklist to be completed by the site superintendent.
Contractor: Follow Attachment I-1; use Attachment I-2 to check installation quality.
Field Superintendent: Complete Attachment I-2 to check installation quality and send completed copy to the project manager or general superintendent.
Criteria for a Quality Thermal Envelope
Insulation should:
Provide a continuous barrier between the inside conditioned space and the outside,
Be installed to the proper R-value,
Be installed without gaps,
Avoid excessive compression,
Be properly labeled or indicate the proper depth to acieve the specified R-value.
Procedures to Install Insulation for a Quality Thermal Envelope
The following steps should be followed in the installation of insulation to ensure efficiency and comfort (for details, see Attachment I-1):
Work with the architect and framer to minimize spaces that are difficult to insulate.
ATTACHMENT I-1
INSULATION INSTALLATION PROCEDURES
WALL INSULATION
Unfaced batt installation; batts shall be:
correctly sized to fit snugly at the sides and ends
installed to completely fill the cavity
cut to fit properly -- there should be no gaps, nor should the insulation be doubled-over or compressed
non-standard-width cavities shall be filled by batt insulation cut approximately one inch (1") wider than the space to be filled
cut to butt-fit around wiring and plumbing, or be split (delaminated) so that one layer can fit behind the wiring or plumbing and one layer fit in front
Faced batt installation, where used as a vapor barrier: additional instructions:
facing should be placed toward living spaces
faced insulation must be properly stapled over the face of the studs; it must be continuous with no penetrations
stapling: the batt flange should be stapled to the face of the framing; flanges from adjacent cavities should overlap per manufacturers specifications on facing
each batt should be stapled approximately every eight (8) inches, or according to manufacturers specifications on facing
all tears or breaks in the facing six (6) inches or longer shall be sealed with duct tape or other waterproof tape. Tears and breaks in the facing should be minimal.
Narrow-framed cavities and "chinking:"
non-standard-width cavities shall be filled by batt insulation cut approximately one inch (1") wider than the space to be filled
narrow spaces (2" or less) at windows, between studs at the building's corners, and at the intersections of partitions and walls shall be filled with small pieces of insulation; care should be taken not to compress the insulation
Special situations:
Installations prior to exterior sheathing or lath
all exterior channels (e.g., at wall junctions and corners) must be filled with insulation
all exterior walls adjacent to tubs and showers must be filled with insulation
Obstructions
insulation shall be cut to fit around wiring and plumbing without compression
insulation shall be placed between the sheathing and the rear of electrical boxes
insulation shall be cut to fit around junction boxes
in cold climates water pipes shall have at least two thirds of the insulation between the water pipe and the outside. If the pipe is near the outside, as much insulation as possible shall be placed behind the pipe and no insulation shall be placed between the pipe and the inside.
Rim joists
all rim joists shall be insulated to the same R-value as the walls
as necessary, insulation shall be cut to fit into the rim joist
an alternative to fitting insulation in a web truss located at the rim joist is to completely cover the truss with insulation, snug to the upper and lower floors
Knee walls and Skylight shafts with framing that will support insulation
all knee walls and skylight shafts shall be insulated to a minimum of R-19
the insulation shall be installed without gaps and with minimal compression
for steel-framed knee-walls and skylight shafts, external surfaces of steel studs must be covered with batts or rigid foam unless otherwise specified on the CF-1R and documented by a form 3R generated by EZFRAME
Knee walls and Skylight shafts without framing that will support insulation
for steel-framed knee-walls and skylight shafts, external surfaces of steel studs must be covered with batts or rigid foam unless otherwise specified on the CF-1R and documented by a form 3R generated by EZFRAME
the house side of the insulation shall be in contact with the drywall or other wall finish. The attic side shall be covered with, and supported by a facing rated for attic exposure to stop air intrusion into the insulation.
HVAC/Plumbing closet
insulate all walls of interior closets for HVAC and/or water heating equipment the same R-value as the exterior walls
BATT CEILING INSULATION
Unfaced batt installation:
batts shall be correctly sized to fit snugly at the sides and ends
batts should fill the cavity
where necessary, batts shall be cut to fit properly -- there should be no gaps, nor should the insulation be doubled-over or compressed. When batts are cut to fit a non-standard cavity, they should be cut to be one inch (1") wider than the cavity.
batts should be cut to butt-fit around wiring and plumbing, or be split (delaminated) so that one layer can fit behind the wiring or plumbing and one layer fit in front
for batts that are taller than the trusses, full-width batts should be used so that they expand to touch each other over the trusses
the insulation must cover the wall top plates
hard covers or draft stops should be placed over all deep drops and interior wall cavities to keep insulation in place and stop air movement. If hard covers or draft stops are missing or incomplete, they should be completed before insulation is completed.
required ventilation must be maintained: for eaves or soffit vents, one-inch (1") of unblocked free air space between the roof sheathing and the insulation is required.
where necessary, use baffles to keep the insulation from blocking the passage of air
insulation shall cover all IC rated lighting fixtures
fixtures that are not IC rated (e.g., halogen lamps, heat lamps) need to be enclosed in an airtight box that meets fire codes, and the box covered with insulation. If fixtures are not IC rated and not enclosed in such a box, they should be replaced or boxed before insulation is completed.
Faced batt installation, where used as a vapor barrier: additional instructions:
facing should be placed toward living spaces
stapling: the batt flange is stapled to the face of the framing; flanges from adjacent cavities should overlap
each batt should be stapled approximately every eight inches (8") or per manufacturer's specifications on the facing
all tears or breaks in the facing six inches (6") or longer shall be sealed with appropriate tape approved by the insulation manufacturer. Tears and breaks in the facing should be minimal.
Special situations:
Insulation at bridging (cross bracing)
batts shall be split lengthwise at the center and packed half into the lower opening and half into the upper opening of bridging (cross bracing) of ceiling and/or floor joists
alternatively, insulation is butted to the bridging and the space is filled with scrap insulation
Rafter ceilings
an inch of air space should be maintained between the insulation and roof sheathing, if necessary to meet local codes
facings and insulation should be kept three inches (3") away from heated flue pipes or chimneys; follow flue manufacturer's recommendations
HVAC platform
verify that appropriate batt insulation is placed below any plywood platform or walks for HVAC equipment installation and access
Attic access
permanently attach rigid foam or a batt of insulation to the access cover using adhesive or mechanical fastener
BLOWN-IN CEILING INSULATION
baffles must be placed at eaves or soffit vents to keep insulation from blocking attic ventilation; required ventilation must be maintained: for eaves or soffit vents, one-inch (1") of unblocked free air space between the roof sheathing and the insulation is required.
hard covers or draft stops must be placed over all deep drops and interior wall cavities to keep insulation in place and stop air movement. If hard covers or draft stops are missing or incomplete, they should be completed before insulation is completed.
small, inaccessible openings shall be hand packed with pieces of batt insulation
attic rulers appropriate to the material installed must be placed around attic to verify depth: 1 ruler for every 250 square feet, evenly distributed around the attic and clearly readable from the attic access
insulation shall be blown to a uniform thickness throughout the attic, with no high or low spots
labels from the insulation bags should be cut out and stapled to a truss vertical near the attic opening
insulation must go underneath and on both sides of obstructions such as cross-bracing and wiring
insulation shall be applied all the way to the outer edge of the wall top plate
insulation shall cover IC rated lighting fixtures
fixtures that are not IC rated (e.g., heat lamps) need to be enclosed in a drywall box and the box covered with insulation. If fixtures are not IC rated and not enclosed in a drywall box, they should be replaced or boxed before insulation is completed.
there shall be no excessive compression of insulation material
clearances around fossil-fuel appliances and heat-exhaust vents shall follow local fire protection codes
no insulation or facing shall be placed in air spaces surrounding metal chimneys or fireplaces; follow manufacturer's recommendations
batt or rigid foam insulation shall be installed in areas where blown-in insulation has not been applied, such as access panels and doors
Special situations:
HVAC platform
pressure-fill the areas under any plywood platform or walks for HVAC equipment installation and access or verify that appropriate batt insulation has been installed
Attic access
permanently attach rigid foam or a batt of insulation that is equal or exceeds the R-value of the insulation on the attic floor to the access cover using adhesive or mechanical fastener
RAISED FLOORS AND FLOORS OVER GARAGES
batts must be correctly sized to fit snugly at the sides and ends, but not be so large as to buckle -- batts should be no more than one inch (1") wider than the cavity
batts must be cut to fit properly -- there should be no gaps, nor should the insulation be doubled-over or compressed
batts should fill the cavity
batts should be cut to butt-fit around wiring and plumbing, or be split (delaminated) so that one layer can fit behind the wiring or plumbing and one layer fit in front
where there is an air space between the insulation and flooring, the headers and band-joists must be insulated
if faced, facing should be placed toward living spaces
MATERIALS SHALL:
comply with Uniform Building Code (including but not limited to 1997 UBC Section 707) and installed to meet all applicable fire codes
meet California Quality Standards for Insulating Material, Title 24, Chapter 4, Article 3, listed in the California Department of Consumer Affairs Consumer Guide and Directory of Certified Insulating Materials
comply with flame spread rating and smoke density requirements of Sections 2602 and 707 of the Title 24, Part 2: All exposed installations must use fire retardant facings which have been tested and certified not to exceed a flame spread of 25 and a smoke development rating of 450. Insulation facings that do not touch a ceiling, wall, or floor surface and faced batts on the undersides of roofs with an air space between the ceiling and facing are considered exposed applications.
be installed according to manufacturer specifications and instructions
R-VALUE AND U-VALUE SPECIFICATIONS:
See CF-1R for minimum requirements; for non-standard assemblies, also see applicable form 3R.
CERTIFICATES:
An Insulation Certificate (IC-1) signed by the responsible party shall be provided that states that the installation is consistent with the plans and specifications for which the building permit was issued. The certificate shall also state the installing company name, insulation manufacturer's name and material identification, the installed R-value, and, in applications of blown-in insulation, the minimum installed weight-per-square-foot consistent with the manufacturer's labeled installed-design-density for the desired R-value.
Note: Appendix I-2 is an Insulation Check List and is available for downloading as an Adobe Acrobat PDF file.