WinterGuard HT-X

CertainTeed WinterGuard HT-X is a self-adhering waterproofing membrane coated with SBS-modified asphalt. HT-X stands for High Tack, High Temperature. It belongs to the residential roof underlayment products from CertainTeed and is formulated to resist the high roof temperatures found under metal roofs.

It is used in critical areas such as roof eaves and valleys, and as a waterproofing underlayment for low-slope shingle, metal, slate and mechanically fastened tile roofing. It is part of the underlayment layer beneath asphalt shingle roofs as well as the other coverings named above.

The top surface carries a tough, tear-resistant film that does not scratch metal roofing laid over it. The adhesive bottom surface is protected by a disposable silicone-coated release film, split lengthwise down the middle to make application easier.

The membrane is rated to withstand temperatures up to 250 degrees F. It is a vapor barrier. Where it covers most of the roof deck, the roof needs proper deck ventilation.

The membrane goes onto a clean, dry, bare deck and never over shingles. It can be repositioned before deck adhesion occurs, and it seals tightly around nails.

• Roll area: 195 ft2
• Roll length: 65 ft
• Roll width: 3 ft
• Thickness: 40 mils
• Selvedge: 3 inches
• Coverage: 1.95 squares per roll
• Shipping weight: 46 lb per roll
• Packaging: 25 rolls per pallet

Test results are reported against ASTM D1970 requirements. Every property below is reported as Pass.

• Maximum load at break, machine and cross-machine direction (ASTM D2523): requirement above 25 lbf/in-width
• Elongation at break of the modified bitumen portion (D2523): requirement above 10%
• Adhesion to plywood at 75 degrees F (D903): requirement above 12 lbf/ft-width
• Thermal stability (D1204): requirement below 0.1 in
• Flexibility temperature (D1970): passes at -20 degrees F
• Tear resistance, machine and cross-machine direction (D4073): requirement above 20 lbf
• Moisture vapor permeance (E96 Procedure BW): requirement below 0.1 U.S. perms
• Self-sealability around nail (D1970): no leakage
• Waterproof integrity of laps (D1970): no leakage

• Intertek CCRR 0636
• ASTM D 1970
• CSA A123.22
• ASTM E108 Class A when used beneath asphalt shingles listed to ASTM D3462

The minimum allowable application slope is 2:12. The membrane is applied when the deck is dry and the air temperature is between 40 degrees F and 120 degrees F. It does not adhere to wet or cold surfaces. For cold weather tack down, only roofing nails are used, and staples are not used under any circumstances with WinterGuard products.

Maximum exposure to sunlight is 180 days, after which a permanent roof surface must cover it. It is not applied over shingles or underlayment of any sort except as shown in certain flashing details in the CertainTeed Master Craftsman Shingle Applicator Manual.

Priming is not required for attachment to wood surfaces. Concrete and masonry surfaces are primed with ASTM D41 primer before application. The membrane can be used over kiln-dried wood substrates. Direct contact with wood plank decks can cause the asphalt compound to soften, flow and drip, because resin or pitch bleeds from new softwoods such as pine, spruce, larch or Douglas fir.

Solvent based sealants and cements are used sparingly because excess solvent damages the polymer modified asphalt coating. Silicone based sealants are not used, as they do not keep adequate long term adhesion to asphalt. The membrane may become slippery under certain weather conditions.

Rolls are stored on end and under cover, and pallets are not stacked three high. Storage temperature stays under 110 degrees F, and rolls stay in their packaging until needed.

The product belongs to the CertainTeed Integrity Roof System, which groups underlayments, shingles, accessory products and ventilation. The product SKU is prfa-698.

The manufacturer warranty covers manufacturing defects and covers the membrane staying watertight for the same period as the shingle warranty above it, up to a maximum of 50 years.