AL:CO Shield Ice & Water Protector

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Detailed Drawings Index

Installation Instructions

  1. ALCO SHIELD can be applied on new construction or when reroofing.  After removal of old roofing, down to the deck, or completion of a new deck, sweep its surface to remove dirt and debris. The deck must be clean, smooth and dry prior to the application of ALCO SHIELD. If any deck boards are damaged or rotted, they must be replaced.

  2. Apply metal drip edge as follows:

    Along eaves, install drip edge first, with ALCO SHIELD on top.
    Along rakes, install ALCO SHIELD first with drip edge on top.
    Prime all metal and concrete surfaces.  

  3. Remove the roll of ALCO SHIELD from box and cut into three (3) equal lengths. Cut shorter lengths if required for the job.  Unroll the material and allow it to “relax” (about 3-5 minutes). Do not remove the release film until you are ready to apply the membrane to the roof.

  4. Remove the lower half of the release film and place the first course of ALCO SHIELD on the roof, parallel to and flush with the eave. The ply line should be located away from the eave edge.  After adhering the lower half of the ALCO SHIELD to the roof, remove the balance of the release film and adhere the rest of the sheet.

    ALCO SHIELD may be tacked with nails to hold it in place until it bonds to the roof. Do not nail through the 4” lap along the top edge of the product.

  5. Apply additional courses as necessary. ALCO SHIELD should be applied a minimum distance of 24” beyond the interior wall line.  In most areas, this will place the ALCO SHIELD well above the maximum ice dam buildup line. Consult the local building codes to determine the proper distance in your area.

  6. Align additional courses parallel to the first course and position them so the bottom edge of the second course exactly overlaps the first course to the marked ply line. The minimum overlaps are 4” on the overlap and 6” on the side laps.

  7. Tack the second course in place, using hand pressure or a roller.  Smooth out the lapped area to insure good adhesion.

  8. When end laps of ALCO SHIELD are required, overlap ends at least 6”. Using hand pressure or a roller, smooth out the overlapped area to ensure good adhesion.

  9. Proceed with the application of the primary roofing material. Do not allow ALCO SHIELD to remain permanently uncovered.  Prolonged exposure to sun and weather will adversely affect this product’s performance and void the warranty.

  10. To install ALCO SHIELD to roof valleys, peel back the release film and center the sheet over the valley. Starting at the bottom, drape and press the ALCO SHIELD into place, working from the center of the valley and out in direction. If overlapping underlayment sheet with another sheet of underlayment, a side overlap should be a t least 4” and an end overlap at least 6”.

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Apply ALCO SHIELD only in dry, fair weather when the air and deck temperature are above 40 degrees Fahrenheit.


Store upright in covered, ventilated area with temperature under 100 degrees Fahrenheit. Maximum storage height limited to two (2) pallets high.


1.0 Sq. Roll                          36” x 33.3 LF                       49/Pallet
1.95 Sq. Roll                        36” x 65.0 LF                       36/Pallet


This product carries a limited one year warranty. You may obtain a copy of this warranty Online here or by a written request addressed to:

580 St. Jean
Detroit, MI   48214

See Sample Installation Drawings on the pages that follow.

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ALCO Shield Underlayment Single layer Drawing

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ALCO Shield Underlayment Double Layer Drawing

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ALCO Shield Underlayment Open Valley Flashing Drawing

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ALCO Shield Underlayment Closed Cut Valley Drawing

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ALCO Shield Underlayment Closed Woven Valley Drawing

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