Copper Flashings - A Manual - 1925 - Page 18
Fig. 47. When a clay tile roof is surmounted by a flat deck covered by copper roofing there are two ways of flashing the junction, both of which are shown in Fig. 47. The method shown on the left is used when the tile finishes below the copper roof level and the roofing laps over the edge of the tile. A clay-tile deck mold is secured to the roof sheathing by copper nails just above a special piece which is called a "top-fixture." The flashing is turned down over the deck-mold far enough to lap 4 inches, the lower edge having been turned back on itself ½ inch for stiffness. The upper or roof edge of the flashing is connected to the roofing copper by a soldered lock seam securely held to the roof sheathing by copper cleats.
The method indicated on the right of Fig. 47 shows the way the flashing is to be placed when the tile ends above the roof instead of below. The flashing is carried up at an angle on a cant strip over a ridge-board and down and out on the tile, lapping about 4 inches. The clay ridge-roll is then placed over the copper flashing, the weight of the roll holding it in place. The flashing is also secured to the copper roofing of the main deck roof by soldered lock seams. In laying both types of flashing care should be taken to avoid sharp angles. The ends of the flashing sheets horizontally should be joined by a soldered lap seam or by a 2-inch lap if not soldered.
Fig. 48. When a clay tile roof abuts a brick wall at the top of the tile roof the junction is flashed as indicated in Fig. 48. Each end of the cap flashing is turned back on itself, the built-in end to act as a dam, and the lower end for stiffness. The flashing is built into the brick work as the wall progresses. The cap flashing should lap the base flashing 4 inches. The base flashing should extend out on the roof tile as far as the edge of the clay tile "top fixture," and before being placed the lower edge should be turned back on itself ½ inch for stiffness. After placing the base flashing in position the upper edge should be secured to the brick work by copper nails driven into the joints of the brick work. To complete the job the cap flashing is then turned down over the base flashing in the usual way. The sheets forming both base flashing and cap flashing should lap horizontally at least 2 inches if the lap is not to be soldered, but if the laps are to be soldered this distance may be reduced to ½ inch.
Fig. 49. When a clay tile roof abuts a brick wall at the sides of the roof the method of flashing to be used is indicated in Fig. 49. The base flashing should extend out on the roof just far enough to avoid puncture by the nails used in securing the clay tile to the roof, and then be turned up at a right angle to the roof ¼ inch and also turned up against the brick wall. The flashing should always be carried up high enough on the brick wall so that the cap flashing when in place will lap the base flashing at least 4 inches. The cap flashing should be laid in the brick joints as the wall is built and stepped as required by the slope of the roof. Before being placed in position each end of the cap flashing should be turned back on itself ½ inch. Each sheet of the cap flashing should lap outside the next lower sheet at least 2 inches, but if the lap is to be soldered this distance may be reduced to ½ inch.
Fig. 50. The process of flashing a roof covered with concrete tile is explained in Figs. 50, 51 and 52. Fig. 50 shows the method to be used when the tile work is penetrated by a vent-pipe. The important points to be considered are: First, the careful bedding in cement mortar of the particular tile or tiles which the pipe penetrates. This is necessary because the mechanical bond between this tile and its neighbors will probably be broken by the pipe. Second, the copper flashing should be carried down to and over the edge of the tile just below the pipe and also up under the next tile above the pipe, as far as the wood batten, to which it should be secured by copper nails. Third, the flashing should be wide enough so that the edges will terminate in a depression of the tile and be turned down into it, as shown in Fig. 51, and not terminate on top of a projection. The flashing around the pipe is done as described in detail in Figs. 29 or 30.
Fig. 51. This drawing indicates the method to be used for flashing a concrete-tile roof ending against a brick wall or chimney, the upper drawing showing the method when the side of the tile roof adjoins the brick work, and the lower showing the method used when the brick work is at the top of the tile roof. For clearness the cap flashing is shown with a straight lower edge, but it should, of course, be turned on itself ½ inch for stiffness. It is built in and stepped in the usual manner for cap flashing in brick work. Attention is called to the method of terminating the base flashing which, in the case of the side wall, should be carried out to a depression in the tile and turned down into it. In the case of the front wall the flashing should be carried down on the roof at least 4 inches and over the edge of the tile next to the brick work. Cap flashings should lap the base flashings at least 4 inches, and be stepped as required by the slope of the roof, and also lap adjoining sheets 2 inches.
Fig. 52 shows a dormer window or other vertical structure on a concrete-tile roof and the method of flashing. The upper part of the drawing shows the flashing against the side wall, and the lower part the flashing against the front wall. In side wall construction the flashing is carried out on the roof and turned up against a cleat supporting the concrete tile and also up on the vertical wall as far as necessary, but never less than 4 inches, and is nailed to the sheathing about every 8 inches. The tile is kept a little distance away from the wall so that the flashing forms a small gutter. Provision must be made at the low point for connecting this flashing with the main gutter by continuing it under the tile to the eaves, or else it must be run out on top of the tile. Against the front wall the flashing is placed against the sheathing and carried up at least 4 inches. When a window occurs in the wall the flashing should be carried well up under the window sill as explained in Fig. 10. The upper edge of the flashing is nailed to the sheathing by copper nails about 8 inches part. The lower edge extends out on the tile from four to six inches, according to the slope of the roof and should be turned back on itself ½ inch for stiffness.
Attention is directed to the method of bedding the tile in cement mortar. This is necessary wherever the tile is cut or wherever water is liable to drive in under the flashing.
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