Ahhhhhh..yes......Resiliency...the reason we need to tape the joints in our roof plywood now....
(Amd) R905.1.1 Underlayment. Underlayment for asphalt shingles, clay and concrete tile, metal
roof shingles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shingles, wood
shakes and metal roof panels shall conform to the applicable standards listed in this chapter.
Underlayment materials required to comply with ASTM D 226, D 1970, D 4869 and D 6757 shall
bear a label indicating compliance to the standard designation and, if applicable, type
classification indicated in Table R905.1.1(1). A minimum 4-inch-wide (102 mm) strip of selfadhering
polymer-modified bitumen membrane complying with ASTM D 1970, installed in
accordance with the manufacturer’s instructions for the deck material, shall be applied over all
joints in the roof decking. Underlayment shall be applied over the entire roof and over the 4-inchwide
(102 mm) membrane strips and shall be applied in accordance with Table R905.1.1(2).
Underlayment shall be attached in accordance with Table R905.1.1(3).
Exceptions:
1. As an alternative, self-adhering polymer-modified bitumen underlayment complying with
ASTM D 1970 installed in accordance with both the underlayment manufacturer’s and roof
covering manufacturer’s instructions for the deck material, roof ventilation configuration
and climate exposure for the roof covering to be installed, shall be permitted.
2. The 4-inch-wide (102 mm) strips of self-adhering polymer-modified-bitumen membrane
are not required for roofs sheathed with lumber having a nominal width of less than 3 feet
(914 mm).