INSTRUCTIONS FOR APPLYING CEDAR PLUS CEDAR SHINGLES AS A CLASS "A" ROOF COVERING SYSTEM Cedar Plus Class "B" labeled cedar shingles must be applied over one layer of ¼" thick Dens-Deck Roof Board manufactured by Georgia Pacific Corporation or with one layer of 72-pound mineral surfaced cap sheet. Fastener length must be increased for the thickness for the Dens-Deck board or the cap sheet. Dens-Deck boards are fastened to spaced or solid sheathing using a minimum of four fasteners to avoid panel shifting prior to the installation of the shingles. If installed on spaced sheathing the horizontal joints of the Dens-Deck must meet on the solid nailing surface. The mineral-surfaced cap sheet is installed mineral surface side up with 2" (51 mm) overlaps on sides and ends, and attached with sufficient number of fasteners to hold the sheet in place prior to installation of the shingles. If installed on spaced sheathing the horizontal overlap must meet on the solid nailing surface. (See figure A).     Roof Pitch and Exposure Proper weather exposure is important, and depends largely on roof slope. On roof slopes of 4" rise in 12" horizontal run (pitch 1/6) and steeper, the standard exposures are: 5" for 16" shingles; 5½" for 18" shingles; and 7½" for 24" shingles. On roof slopes less than 4/12 to a minimum of 3/12, reduced exposures are recommended. Roof Application Shingles normally are applied in straight, single courses. Shingles must be doubled at all eaves. Butts of first-course shingles should project 1½" beyond the first sheathing board. Spacing between adjacent shingles (joints) should be ¼". Joints in any one course should be separated not less than 1½" from joints in adjacent courses, and joints in alternate courses should not be in direct alignment. Fasteners Hot dipped zinc coated nails or stainless steel staples are recommended. However, any U.B.C. approved corrosion-resistant fasteners can be used. Apply each shingle with two (only) fasteners. Each fastener should be placed not more than ¾" from the side edge of the shingle and not more than 1" above the exposure line. Use 3d (1¼") nails for 16" and 18" shingles, and 4d (1½") for 24" shingles; In all cases, fasteners should be long enough to penetrate at least ¾" or through the sheathing. Drive them flush, but not so that the head crushes the wood. Valleys The roof valley flashing shall be provided of not less than No. 28 gauge pre-painted baked enamel metal applied over an undelayment of not less than Type 15 felt. The metal shall extend at least 8" from the center line each way. WARNING: Both raw and fire retardant treated cedar products contain a level of tannic acid that can cause corrosion to unprotected metals and concrete surfaces. Pre-painted galvanized or pre-painted aluminum gutters are recommended. Initial water run-off over both raw and fire retardant cedar can cause staining. A low pressure wash of the roof immediately after application recommended. Chemco is not responsible for any direct or indirect damages caused by water run-off.