SPECIFICATION GUIDELINES

This information has been designed to aid architects and builders in specifying red cedar shingles and handsplit shakes. It suggests a standardized terminology and style for ordering in the hope of improving accuracy and it incorprates a general outline of the lastest application information. Please note, however, that this is a specification guide only. It is not intended to be a complete reference to the characteristics or application of red cedar shingles and shakes. Comprehensive information on such subjects is available from your local building code department.

General Specification Data

1. The contractor shall cover all roof surfaces with shingles or shakes bearing the I.C.B.O. or other official grade marked label.

2. Shingles/shakes for roofs shall be (specify grade and length).

3. Shingles/shakes for outer courses shall be (specify grade and length).

4. Shingles/shakes for undercourses shall be (specify grade and length).

5. Shingles/shakes shall be laid with a weather exposure of (specify in inches/millimeters).

Roof Application-Sheathing Boards

6. Shingles and shakes shall be applied over spaced sheathing. Solid sheathing is acceptable and may be required in seismic regions or under treated shakes and shingles. In areas where wind-driven snow is common, solid sheathing is recommended under shakes.

7. All open sheathing shall be 1" x 4" (25.4 mm x 101.6 mm) or 1"x 6" (25.4 mm x 152.4 mm) boards. (1"x 6" (25.4 mm x 152.4 mm) boards for shakes).

8. All solid sheathing shall be lumber, such as shiplap, or softwood panels, applied according to specifications of the American Plywood Association.

Roof Felt Interlay (for shakes only)

9. Contractor shall apply a 36"(914.4 mm) wide strip of No. 15 minimum roofing felt at the eave line. An 18" (457.2 mm) wide strip of No. 30 roofing felt (or No.15 felt depending upon code requirements) shall be applied over the top portion of the shakes and extend onto the sheathing. Bottom edge of felt shall be positioned at a distance above the butt equal to twice the weather exposure. Note: felt interlay between courses is not necessary when straight-split, or tapersplit shakes are applied in snow-free areas at weather exposures of less than one-third the total shake length (3-ply roof).