Engineered Framing Systems, Inc. Wet Weather Policy: Wood Roof or Floor Sheathing Exposed To Prolonged Moisture.
During wet winter seasons, there is cause to be concerned of wood roof sheathing being exposed to prolonged moisture exposure. The following policy and procedure addresses this issue:
1. Engineered Framing Systems, Inc. will follow the Engineered Wood Association’s (APA) recommended 1/8” spacing of sheathing at the time of installation.
2. It is most important that all interested parties verify this spacing during the daily installation stage of construction.
3. Once subjected to moisture, this 1/8” spacing will allow the sheet to expand, filling the 1/8” void created during the installation of the individual sheets.
4. The sheathing manufacturers and the APA agree that the moisture induced expanded sheet has performed and reacted to the intake of moisture as expected. No future movement of the sheathing should be expected.
5. If just prior to the time the roof membrane is being applied, all sheets are laying flat, with no bending or buckling, the roof deck should be considered acclimated, stable and ready for roofing.
6. Re-gapping of sheets by a “skill saw” to recreate a 1/8” gap should never be allowed as it may cut off the sealer that was previously applied to the sheathing edge and may result in the sheet absorbing additional moisture.
7. During the wet season Engineered Framing Systems, Inc. recommends that the roofing subcontractor stay close to 25,000 sq. ft. of our horizontal sheathing installation.
8. Engineered Framing Systems, Inc. recommends against the installation of large areas of roof that have the potential of being exposed to wet weather conditions over a prolonged period of time. Proceeding to do so will require an agreement of financial participation by owner for future possible repairs if they are a result of such action.
Revised 3-22-09
