Underlayment & Barriers

Protect your home or building with underlayment and water-resistant but vapor permeable barriers. Building underlayment is usually used when working on roofs and external walls to provide a barrier on the inside of the construction work in case your house siding is not water-tight or your roof tiles are not moisture resistant. 

Our range of building underlayment includes specialty insulated or woven reinforced vapor barriers for crawl spaces and smaller areas especially common in roof and attic construction work. As well as specialty synthetic roofing underlayment to protect the construction of the roof and keep moisture, vapors, and any weather damage to the roof tiles out of the structure.

For underlayment and barrier insulation and reinforcement for walls and sheds take a look at our selection of poly sheeting, underslab vapor barriers, as well as pipe boot and patch. Flashing, adhesives, and sealants are also available to stock up on accessories and must-have products to complete the job. You will find underlayment and barrier brands that have become house names such as Viper, Aluf Plastics, and our very own Roofing4US. 

Browse below to find underlayment or vapor barrier products for your project and contact one of our team members via Live Chat if you have any questions about the products or which underlayment to choose for your specific project.

TPO Plus Roof Membranes - All Sizes
TPO Plus Roof Membranes - All Sizes Flex Membranes
Vendor
Roofing4US
Regular price
from $502.08
Sale price
from $502.08
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per 
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Viper CS 10 mils Crawl Space Class A Woven Reinforced Vapor Barrier - Full Range
Viper CS 10 mils Crawl Space Class A Woven Reinforced Vapor Barrier
Vendor
Viper
Regular price
from $225.16
Sale price
from $225.16
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Unit price
per 
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Viper II Underslab Vapor Barrier Class A - Full Range
Viper II Class A 15-mil
Vendor
Viper
Regular price
$441.61
Sale price
$441.61
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Unit price
per 
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Viper CS Crawl Space Class A Woven Reinforced Vapor Barrier - 12 ft x 100 ft x 16 mils
Viper CS Crawl Space Class A Woven Reinforced Vapor Barrier - 12 ft x 100 ft x 16 mils
Vendor
Viper
Regular price
from $492.47
Sale price
from $492.47
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Unit price
per 
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Perforated Radiant Barrier Industrial Grade Reflective Insulation Foil - All Sizes
Radiant Barrier Industrial Grade Perforated Reflective Insulation Rolls - All Sizes Attic Insulation
Vendor
Super R
Regular price
from $86.88
Sale price
from $86.88
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Unit price
per 
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Grayhawk Synthetic Underlayment - All Sizes
Vendor
Gray Hawk
Regular price
$48.70
Sale price
$48.70
Regular price
Unit price
per 
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Insul-Barrier Crawl Space Vapor Barrier - 4 ft x 25 ft
Insul-Barrier Crawl Space Vapor Barrier
Vendor
Insul Barrier
Regular price
$97.06
Sale price
$97.06
Regular price
Unit price
per 
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Viper CS 6.5 mils Crawl Space Class A Woven Reinforced Vapor Barrier - Full Range
Viper CS 6.5 mils Crawl Space Class A Woven Reinforced Vapor Barrier
Vendor
Viper
Regular price
from $159.13
Sale price
from $159.13
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Unit price
per 
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Diamond Perforated Radiant Barrier Reflective Insulation Foil - All Sizes
Super Radiant Barrier Perforated Diamond Insulation Rolls
Vendor
Super R
Regular price
from $61.88
Sale price
from $61.88
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Unit price
per 
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Synthetic Roofing Underlayments EXO25-SB (Pallet of 42 Rolls)
Synthetic Roofing Underlayments Stringer EXO25-SB
Vendor
National Nail
Regular price
$2,779.98
Sale price
$2,779.98
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Unit price
per 
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Viper CS II 10 mils Crawl Space Class A Vapor Barrier - Full Range
Vendor
Viper
Regular price
from $145.59
Sale price
from $145.59
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per 
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Cetainteed MemBrain Vapor Retarder - All Sizes
Cetainteed MemBrain Vapor Retarder - All Sizes
Vendor
Certainteed
Regular price
from $182.40
Sale price
from $182.40
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per 
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Raptor Underlayment - All Sizes
Vendor
Raptor
Regular price
$3,360.00
Sale price
$3,360.00
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Unit price
per 
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StarWrap Superior Synthetic Felt Underlayment 4 ft x 250 ft
StarWrap Superior Synthetic Felt Underlayment 4 ft x 250 ft 10sq
Vendor
StarWrap
Regular price
from $2,720.00
Sale price
from $2,720.00
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per 
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Crawl Space 18 In x 200 ft x 10 mils Class A Vapor Barrier Woven Reinforced
Crawl Space 18 In x 200 ft 10mil Class A Vapor Barrier Woven Reinforced
Vendor
Viper
Regular price
from $69.88
Sale price
from $69.88
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Unit price
per 
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Wraptor House Wrap Tape 2 in x 216 ft (36 Rolls)
Vendor
Wraptor
Regular price
$341.36
Sale price
$341.36
Regular price
Unit price
per 
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Wraptor Building HP House Wrap 11 perm - Full Range
Wraptor HP Building House Wrap 11 perm - Viper
Vendor
Wraptor
Regular price
from $110.81
Sale price
from $110.81
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Unit price
per 
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Wraptor Building House Wrap 5 perm - Full Range
Wraptor HP Building House Wrap 5 perm - Viper
Vendor
Wraptor
Regular price
from $16.92
Sale price
from $16.92
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Unit price
per 
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Owens Corning Pinkwrap Housewrap Insulation (All Sizes)
Owens Corning Pinkwrap Housewrap Insulation (All Sizes) House Wraps
Vendor
Owens Corning
Regular price
from $121.80
Sale price
from $121.80
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per 
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Viper Venom Barrier Class A 16 ft x 100 ft x 20 mils
Viper Venom Barrier 20mm Class A 16 ft x 100 ft Grey/Black
Vendor
Viper
Regular price
$638.75
Sale price
$638.75
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per 
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Viper VaporCheck 12 ft x 200 ft - All Thicknesses
Viper I Class A 12 ft x 200 ft Orange
Vendor
Viper
Regular price
from $653.29
Sale price
from $653.29
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Unit price
per 
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Insul-Tarp Under Slab Insulation 1/2 In - All Sizes
Insul-Tarp Under Slab Insulation 1/2 In
Vendor
Insul-Tarp
Regular price
from $105.88
Sale price
from $105.88
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Unit price
per 
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Nu-Age Film 10+ Engineered Poly Sheeting 20ft x 100ft x 4.45 mils - All Colors
Nu-Age Film 10+ Engineered Poly Sheeting 20ft x 100ft x 4.45mm
Vendor
Nu Age
Regular price
from $3,444.03
Sale price
from $3,444.03
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per 
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Nu-Age 6+ Engineered Poly Sheeting 2.75 mils - Full Range
Nu-Age  6+ Engineered Poly Sheeting  2.75mm
Vendor
Nu Age
Regular price
from $2,713.35
Sale price
from $2,713.35
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Unit price
per 
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Nu-Age Film 4+ Engineered Poly Sheeting 1.55 mils - Full Range
Vendor
Nu Age
Regular price
from $2,354.82
Sale price
from $2,354.82
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Unit price
per 
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Viper Vapor Patch 11.5 In x 50 ft Pipe Boot and Patch (5 Rolls)
Vendor
Viper
Regular price
$380.94
Sale price
$380.94
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Unit price
per 
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Viper Vapor Scrim Reinforced Poly Sheeting - Full Range
Viper Vapor Scrim 6-mil & 10-mil
Vendor
Viper
Regular price
from $3,770.82
Sale price
from $3,770.82
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Unit price
per 
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Viper II Underlslab Vapor Barrier Class C 14 ft x 210 ft - Full Range
Viper II Class C 14' x 210' - 6-mil
Vendor
Viper
Regular price
from $322.79
Sale price
from $322.79
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per 
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Viper II Platinum Under Slab Vapor Barrier Class A 14 ft x 210 ft x 8 mils
Viper II Platinum 8-mil Class A 14' x 210' Silver
Vendor
Viper
Regular price
$361.75
Sale price
$361.75
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per 
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20 ft x 100ft x 6mm Poly Sheeting (25 Rolls)
PS201006 Extra Strong 4 mil 20ft Poly Sheeting - Aluf Plastics
Vendor
Aluf Plastics
Regular price
$1,548.12
Sale price
$1,548.12
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Unit price
per 
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20ft x 100ft x 4mm Poly Sheeting (25 Rolls)
PS201004 Extra Strong 4 mil 20ft Poly Sheeting - Aluf Plastics
Vendor
Aluf Plastics
Regular price
$1,031.88
Sale price
$1,031.88
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Unit price
per 
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12ft x 100ft x 6mm Poly Sheeting (36 Rolls)
PS121006 Extra Strong 6 mil 12ft Poly Sheeting - Aluf Plastics
Vendor
Aluf Plastics
Regular price
$1,337.40
Sale price
$1,337.40
Regular price
Unit price
per 
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