Owens Corning

WeatherLock® Granulated installed between the roof deck and the roofing helps prevent damage caused by wind-driven rain and ice damming. This exclusive Owens Corning® product is a self-adhesive roofing underlayment for asphalt shingles, wood shakes or quarry slate roofs.


Precautions:

Read and understand all instructions and precautions before applying WeatherLock® Granulated.

  • Check local building codes prior to the application of this product.
  • Follow the recommendations of the roof covering manufacturer and the Asphalt Roofing Manufacturer’s Association.
  • WeatherLock® Granulated is intended for use on roof slopes of 2:12 and greater only.
  • When installing WeatherLock® Granulated over the entire roof deck, proper ventilation is required. Consult a design professional and local building codes for ventilation requirements.


Roof Deck:

Ensure the decking substrate meets the requirements of the roof covering manufacturer and local building codes.

  • 6 inch minimum roof deck board width, minimum 3/4 inch thick, with minimum 1/8 inch spaces between boards.
  • Minimum 3/8 inch plywood.
  • Minimum 7/16 inch OSB (Oriented Strand Board).

Deck spacing cannot exceed 1/4 inch between roof boards or between plywood or OSB. Check local building codes.


Deck Preparation:

  1. WeatherLock® Granulated can be applied on new construction or when reroofing, provided existing shingles have been removed. Remove all old roofing down to the deck, or in new construction, apply over the new deck.
  2. Sweep the deck surface to remove dirt, dust, debris and loose nails. The deck must be clean, smooth, frost free and dry for at least 24 hours before applying underlayment. Replace any damaged or rotted deck boards.
  3. No primer is necessary on a plywood deck. OSB may require priming.


Eaves Preparation:

  1. Ensure metal drip edge is nailed properly. WeatherLock® Granulated should be applied over the metal drip edge at the eaves unless otherwise permitted by local building codes.
  2. WeatherLock® Granulated should be applied under the drip edge at the rake.

Step 1

WeatherLock® Granulated should be applied in valleys before doing eaves applications with underlayments. Along a roof valley, underlayment can be installed as a liner. For maximum protection, the roll width should remain intact and extend 18 inches on either side of the valley. Peel back the poly backer sheet and press underlayment into place, working from the center of the valley or ridge outward in each direction. Always apply valleys starting at the low point and work upwards. If an overlap is needed, be sure to overlap the previous piece by 6 inches. See Fig. 1. The overlap must be firmly hand rolled to ensure a weather tight bond. See Fig. 2.

Fig. 1+2

Step 2

Unroll WeatherLock® Granulated and cut into 10 foot to 20 foot lengths. Allow to relax for 3 to 5 minutes before installing. Failure to follow this step may result in product wrinkling, which may not be covered under the product Limited Warranty.

Step 3

Starting at the eaves edge, lay WeatherLock® Granulated parallel to the eaves, with the lower edge of the underlayment flush with the outside of the drip edge. The lower edge of the underlayment is the edge that doesn’t have a selvage edge. Fold the underlayment away from the edge onto itself. Remove the lower half of the release sheet, starting at the middle of the underlayment to the edge. See Fig. 3. Place the underlayment with the exposed rubberized asphalt onto the deck, pressing firmly into place.

Fig. 3

Step 4

Fold the top half of WeatherLock® Granulated toward the roof edge over itself. Remove the release sheet and reposition the underlayment, pressing firmly into place. Repeat process as needed. See Fig. 4.

Prehead

Step 5

After the course is in place, roll the entire course with an 80 pound roller. Start at the center and work outward to remove trapped air. See Fig. 5.

Fig. 5

STEP 6

On steep slope applications over 3:12 pitch or in high-wind areas, back nail at 12 inches on center through the selvedge edge. Use smooth shank galvanized roofing nails unless otherwise required by local codes. Do not use staples.

Step 7

Repeat process as needed, overlapping additional courses 3 inches on the selvedge edge. The laps must be firmly hand rolled to ensure a watertight bond. Overlap the end lap where the 2 rolls meet by 6 inches. End laps should be offset a minimum of 6 feet on adjacent courses. See Fig. 6.

Fig 6

Step 8

WeatherLock® Granulated should extend from the eaves to a point 24 inches inside the exterior wall, measured horizontally. Consult local building code for specific requirements.

STEP 9

Along the rake edge, overlap eaves material a minimum of 6 inches. Align WeatherLock® Granulated flush with the deck edge. Install per instructions above. Apply drip edge over underlayment after material is adhered.

STEP 10

Cover WeatherLock® Granulated with final roof covering. Do not allow the underlayment to remain uncovered more than 30 days. Prolonged exposure to wind, sun and weather will adversely affect this product’s installation and performance.

Precautions:

  1. WeatherLock® Granulated should be installed by a professional roofing contractor. The underlayment is designed to be covered by asphalt shingles, wood shakes or quarry slate roof assemblies. Protection from sunlight is required to ensure its long-term performance.
  2. WeatherLock® Granulated should be applied when ambient and substrate temperatures are 40°F (4.4°C) or higher. Do not leave exposed for more than 30 days.
  3. WeatherLock® Granulated is a moisture and vapor barrier. Since ice build-up is partially a function of ventilation, the spaces under the covered deck area and the attic space must be ventilated in accordance with local building codes.
  4. WeatherLock® Granulated is intended for exterior roof deck application only.
  5. Shingles should not be installed over wrinkled or buckled underlayment.
  6. For fastening shingles, use galvanized steel, stainless steel or aluminum nails minimum 12 gauge shank with 3/8 inch diameter head. Fasteners that comply with ASTM F1667 are recommended. Check local building codes.
  7. WeatherLock® Granulated must NOT be installed over uncured caulking, uncured sealants or flexible vinyl. If the underlayment is installed over any of these materials, the adhesive will melt and run, causing unsightly streaks and drips. It is the installer’s responsibility to determine whether all the materials used are compatible with each other. Contact the caulking or sealant manufacturer to ensure the product is compatible with asphalt. Caulking and sealants must be fully cured before covering with the underlayment.
  8. Use extreme caution when installing underlayment. The underlayment surface may be slippery even when dry. Use a fall protection system when installing. Consult OSHA for Guidelines for Fall Protection (29 CFR 1926.500).
  9. For best results, apply WeatherLock® Granulated when the air temperature is over 40°F (4.4°C) but below 90°F (32.2°C). When temperatures are under 40°F (4.4°C), underlayment will not fully adhere until warmer temperatures. Store at room temperatures prior to installing product in cold weather. If applied in temperatures above 90°F (32.2°C), it may become difficult to remove the release poly backing. If this situation should occur, move product into a shaded area until the underlayment is cool. Once cooled, the release poly backing can be easily removed.
  10. Store WeatherLock® Granulated in a dry, well-ventilated area and stand upright. Do not store at 90°F (32.2°C) or warmer for extended periods of time. Do not store in direct sunlight. Provide cover on top and sides, allowing for adequate ventilation. When applying underlayment, always follow local building codes and the shingle manufacturer’s instructions for installation of its product.

For Technical Inquiries, please call 1-800-GET-PINK® (1-800-438-7465).

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