This technical letter is intended to provide application recommendations when installing GCP’s self-adhered underlayments along the eaves.
GRACE ICE & WATER SHIELD®, GRACE ICE & WATER SHIELD® HT, GCP granular underlayment , GRACE SELECT™ and GRACE ULTRA™ should be applied directly to a clean, dry, continuous structural deck following GCP’s published surface preparation requirements and application instructions. Some suitable deck materials include plywood, wood composition (OSB), wood plank, metal, concrete or gypsum sheathing.
GCP’s self-adhered underlayments are intended to be applied starting at the roof eave, and extend upslope a minimum of 24 inches beyond the inside face of the exterior wall line of a building or according to local codes and regulations. If the underlayment is intended to extend onto fascia, a metal drip edge or gutter should be installed to prevent permanent exposure to ultraviolet light.
The metal drip edge or wood starter shingle should be placed over the membrane as shown in standard GCP detail drawings. The GCP self-adhered underlayments should not be installed over cedar shingles.
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This document is only current as of the last updated date stated below and is valid only for use in the United States. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on www.gcpat.com. Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.
Last Updated: 2019-03-12