Copper Flashings - A Manual - 1925 - Page 24
Fig. 63. A method of flashing a projecting terra-cotta balcony enclosed by a metal rail with a door or window opening to it is shown in Fig. 63. Particular attention is called to the method of fastening the outer edge of the copper work to the terra cotta as shown in detail in the lower left-hand corner. When designing the terra cotta, provision should be made for a step 1¼ inches or more in height above the top molding. When the terra cotta is cast, and while it is still in a plastic state, a row of holes is punched in the face of this step about ⅜ of an inch in diameter, 1½ inches deep, and 8 or 9 inches apart. Before the copper is placed there should be inserted into these holes cylinders of sheet lead of a length about ⅛ inch less than the depth of the hole and a diameter the same as that of the hole. The edge of the copper flashing containing a row of holes corresponding to the holes in the terra cotta is then turned down over the step at least 1 inch. A No. 12 round-head brass wood-screw is inserted through the copper and into the lead cylinder. As the screw is driven home it expands the lead cylinder, forcing it against the sides of the hole in the terra cotta, forming in effect an expansion bolt, and making a tight and secure fastening. It is generally not necessary to solder over the top of the screw-heads but if much water will come over the edge of the step it is good practice to solder. After being thus secured at the outer edge the copper is laid over the floor of the balcony, using soldered lock seams where necessary, and then turned up against the masonry at least 4 inches where it is lapped by the cap flashing. When the flashing is penetrated by upright posts such as the corner posts of the balcony rail, in this instance, the place where such penetration occurs must be carefully protected by some means such as described in detail in Fig. 66. The regular flashing being first completed, then penetrated as required, and the corner post secured to the masonry, the copper cap is formed around the post or slipped over it and soldered to the flashing and filled with waterproofing-compound. (See Fig- 66 for a complete description of this method.)
The cap flashing is placed before the terra-cotta sill, the wood sill, or the balcony-floor flashing are in position. It is made wide enough so that on completion it will lap the floor flashing 4 inches, extend through the wall under the terra-cotta sill, and up and under the wood sill. After the cap flashing is in place the terra-cot ta sill is placed; then the wood sill. Some prefer to make the flashing wide enough so that it will even extend up in back of the wood sill, but if a water-bar is used this is not necessary. The use of a copper water-bar at the joint between the wood and terra-cotta sills is recommended. A complete description of this feature and the method of its application may be found in the drawing and description of Fig. 11.
Fig. 64. When a terra-cotta balcony or similar projecting feature serves as the base for columns, pilasters, or other projections above the floor of the balcony, the flashing is applied as shown in Fig. 64. It is placed in a similar manner to that described for Fig. 63 except that the cap flashing placed under the terra-cotta window sill is also carried around under the column bases, into the joints of which it is set (as shown by the section in the lower left-hand corner), and built in as the masonry progresses, and before the base flashing and that of the balcony floor is in position. Afterwards the cap flashing is turned down over the base flashing at least 1 inch and the seam soldered.
Fig. 65. A projecting window-cap or cornice of terra cotta surmounted by a terra-cotta balustrade is flashed and the rail steadied and secured to the roof as shown in Fig. 65. Attention is called to the method of avoiding movement of the rail by bracing it from the roof with bronze rods. For this purpose a ⅜-inch bronze bar extending the length of the rail is placed on top of the balusters and connected by vertical rods to the steel framing below and also to a stay rod from the main roof. It is important that the points where the ends of these rods are fastened to the main roof be well-flashed. A complete description and a drawing of a suggested means of doing this is given in Fig. 28.
Fig. 66. The left-hand side of the lower part of Fig. 66 shows a half-section and the right-hand side shows a half-elevation of a method of forming a flashing cap of copper and securing it to the regular roof flashing at such places as it may be necessary to penetrate the roof flashing to permit the passage of rods, dowels, anchors or similar metal shapes. In the illustration the cap is shown round but it may be made of any shape, and it should conform roughly to the contour of the penetrating member. The regular flashing sheet is cut at the points of penetration and the surplus metal turned up against the rod. After the regular flashing is completed the cap is placed in position. The cap is made out of a flat piece of copper with the lower edge turned out. This piece is either bent around the rod and the ends lapped and soldered or the ends soldered first and slipped over the top of the rod. The lower edge (previously turned out) is then soldered to the flashing. Upon completion the cap is filled with a waterproofing-compound. The cap must be made large enough so the sides will clear the rods, etc., at least 1 inch. Two examples of the use of this cap are shown in Figs. 63 and 65.
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