Copper Flashings - A Manual - 1925 - Page 33
33. Open Valley Flashings. (-1.) Open valleys shall be not less than 4 inches wide. The proper width shall be determined by the following rule: Starting at the top with a width of 4 inches, increase the width 1 inch for every 8 feet of length of the valley. Flashing pieces shall be full length sheets, and of sufficient width to cover the open portion of the valley and extend up under the roof covering not less than 4 inches on each side.
There shall be no longitudinal seams in open valley flashings. The cross seams at the ends of sheets shall be locked and soldered. Edges shall be turned back ½ inch and held in place by cleats spaced not more than 12 inches apart, and nailed to the sheathing with two nails.
(-2.) "Fold-over" Flashings shall be used, of such design as to allow not less than 3 inches beyond the fold to be covered by the roofing. They shall be secured by cleats not more than 12 inches apart.
(-3.) Where two valleys of unequal size come together, or where the areas drained by the valley are unequal, there shall be placed in the valley a "crimp” angle, or Tee not less than 1 inch high. This may be formed in the valley sheet before placing, or it may be made of a separate piece soldered to the valley sheet.
34. Closed Valley Flashings. (—1.) Built-In Method. Flashing pieces for closed valleys shall be of sufficient length to extend 2 inches above the top of the roofing piece and lap the flashing piece below 3 inches, and of width sufficient to extend up the sides of the valley far enough to make the valley 4 inches deep. They shall be placed with the roofing so that all pieces are separated by a course of shingles or slate. Pieces shall be set so as to lap at least 3 inches and to be entirely concealed by the roof covering. They shall be fastened by nails at the top edge only.
(-2.) Large Piece Method. Before the roof covering is laid this contractor shall place in all valleys long strips of copper of sufficient width to make a trough at least 4 inches deep. These strips shall be laid from bottom to top of the valley with a 4-inch lap, unsoldered. Where such strips are not over 12 inches wide they shall be fastened with nails spaced every 18 inches along the outer edge. Strips over 12 inches wide shall be fastened by 1½-inch cleats, spaced every 30 inches.
(-3.) All closed valley flashings shall be made with a "crimp" or ridge down the center equal to the full thickness of the roof-covering courses.
35. Cricket or Saddle Flashings. Crickets or saddles formed back of all vertical surfaces, such as chimneys, etc., breaking through sloping roofs, shall be covered with copper. The flashing of these crickets shall be made a part of the flashing along the sides of the chimney, etc.
36. Window and Door Head Flashings. Window and door frames set in frame construction shall have a flashing of copper over the head. This flashing shall be set after the frame is placed and shall be carried up the wall 2 inches above the butt of the second course of shingles, slate, etc., and in no case less than 3 inches above the window head. The bottom edge of the flashing shall be
(-A.) secured to the trim by an edge-strip as specified elsewhere.
(-B.) turned down over the trim and shall finish back of, and be secured by, the outside molding of the trim.
(-C.) nailed at 1-inch intervals to the vertical face of the trim.
(-D.) bent at a sharp angle to bear tightly against the top fillet of the molding, and the upper edge of the flashing, under the shingles, shall be secured by nails placed about 8 inches apart.
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