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INSULATION INSPECTION & IMPROVEMENT
ACOUSTICAL SEALANT CHOICES
AIR LEAK MINIMIZATION
ASBESTOS IDENTIFICATION IN BUILDINGS
BASEMENT CEILING VAPOR BARRIER
BASEMENT HEAT LOSS
BUCKLED FOUNDATIONS due to INSULATION?
CATHEDRAL CEILING INSULATION
CATHEDRAL CEILING VENTILATION
CEILINGS, DROP or SUSPENDED PANEL
DEW POINT TABLE - CONDENSATION POINT
DUCT INSULATION, ASBESTOS PAPER
FIBERGLASS PARTICLE CONTAMINATION
Fiberboard Insulation Sheathing Mold
FIBERGLASS INSULATION MOLD
FIREPROOFING ASBESTOS SPRAY-ON
FRAMING DETAILS for BETTER INSULATION
FRAMING DETAILS for DOUBLE WALL HOUSES
FRAMING METAL STUD PERFORMANCE
FREEZE-PROOF A BUILDING
HEAT LOSS in BUILDINGS
HEAT LOSS PREVENTION PRIORITIES
HEAT LOSS R U & K VALUE CALCULATION
HOUSEWRAP AIR & VAPOR BARRIERS
HOUSE DOCTOR, how-to be
HUMIDITY LEVEL TARGET
ICE DAM PREVENTION
INSULATION AIR & HEAT LEAKS
INDOOR AIR QUALITY & HOUSE TIGHTNESS
INSULATION FACT SHEET- DOE
INSULATION INSPECTION & IMPROVEMENT
INSULATION R-Values & Properties
LEED GREEN BUILDING CERTIFICATION
LOG HOME ENERGY EFFICIENCY
MOLD in FOAM INSULATION, RESISTANCE
MOISTURE CONTROL in BUILDINGS
NOISE / SOUND DIAGNOSIS & CURE
RIGID FOAM USE INDOORS
SHEATHING, FOIL FACED - VENTS
SLAB INSULATION, PASSIVE SOLAR
STAINS on & in BUILDINGS, CAUSES & CURES
STRAW BALE CONSTRUCTION
STUCCO WALL METHODS & INSTALLATION
STUCCO OVER FOAM INSULATION
SWEATING (CONDENSATION) on PIPES, TANKS
Thermal Expansion Cracking of Brick
THERMAL IMAGING, THERMOGRAPHY
THERMAL MASS in BUILDINGS
THERMAL TRACKING Indicates Heat Loss
TRUSS UPLIFT, ROOF
VAPOR BARRIERS & CONDENSATION in BUILDINGS
VENTILATION in BUILDINGS
WALL CONSTRUCTION BARRIER vs CAVITY
WIND WASHING INSULATION At EAVES
WINTERIZE A BUILDING
Exposed foam board insulation fire hazards: this Q&A article discusses the requirement for a fire-resistant covering for foam and foam-board board building insulation. Also see Foam Board Insulation, POLYSTYRENE FOAM INSULATION, and BUILDING SAFETY HAZARDS GUIDE.
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What coverings are acceptable for foam insulation used indoors?
I am reinsulating a house that has concrete block walls, a stucco exterior, and 3/4-inch foil-backed gypsum board over furring strips on the building interior.
If I glued foam insulating board directly over the existing plaster wall finish, would paneling be sufficient covering? Will the foil backing on the gypsum board create a cold-side vapor barrier? - Gordon Reed Jr., Kingsford MI.
In the photograph at left, foam insulating board is shown on a garage ceiling below a second floor bedroom - this material should have been covered with fire rated drywall to meet local building code specifications for fire safety.
Answer: Fire Code Requirements for Covering Foam Insulating Board
Since most fire codes call for a minimum of half-hour fire rating over foam insulations, paneling would probably not provide a sufficient fire barrier over the foam insulating board. New 1/2-inch drywall is usually called for [and in some installations, fire-rated drywall or thicker drywall may be required for local codes and for certain applications].
The thin foil used on the back of drywall will create a moderate cold-side vapor retarder, but the exact permenance is not published for foil-backed gypsum board.
The safe tack is to use a highgraade air/vapor barrier on the inside, keeping it much less permeable than the cold side barrier. We suggest foil-faced foam insulating board with the joints sealed with foil tape.
Watch out: depending on whether or not the foil backing on the existing foil-backed gypsum board is perforated or not, the perm rating of that surface could be near zero - that is, very resistant to moisture movement, forming a moisture barrier in the "wrong place".
So it would also be a good idea to take measures to keep interior building moisture levels to a moderate level. See HUMIDITY LEVEL TARGET
Background on foam board insulation and fire protection:
Foam insulation board should not be left exposed in building interiors.
While many modern foam insulating products do not themselves readily support combustion (that is they don't catch fire and burn alone) they may give off thick acrid or toxic black smoke in a fire, making it difficult to safely exit the burning building.
Foam Insulation Alternatives to Solid Foam Board Insulation
Various foam insulation products that are sprayed in buildings, including UFFI, Icynene, Latex, and other insulating foams as well as fire resistant spray foam insulation used for sealing building penetrations, a different product from the foam board insulation discussed here, are described at INSULATION IDENTIFICATION GUIDE and at Foam Insulation Types - Visual Id.
The link to the original Q&A article in PDF form immediately below is preceded by an expanded/updated online version of this article.
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