7.1. Attachments

7.1A. Typical Copper Cleats

The typical copper cleats shown are usually 16 oz. copper, at least 2" wide. They are attached to the deck or nailable inserts with two copper, brass, bronze, or compatible stainless steel nails or screws. When cleats are used on flat or nearly flat surfaces, the end of each cleat should be folded back over the nail heads to prevent possible damage to the covering sheet by expansion and contraction, traffic or other forces. When fixed cleats are used on vertical surfaces or not exposed to traffic, this is not necessary.

DWG iconDownload CAD File Typical Fixed Cleats

Detail 1: is used to form a hook over the upstanding flange of the lower pan only, allowing some differential movement between pans in a standing seam roofing system. Detail 2 is used to form hooks over both upstanding flanges of the pans in a standing seam roofing system, locking them both together to minimize differential movement.

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7.1B. Typical Copper Hold-Downs

Copper hold-downs are used to prevent the lifting of large, flat portions of copper from the substrate, while allowing thermal movement. They are typically used on wide gutters, extended gutter apron pieces, and wide apron flashings. For the through fastener hold-down, the maximum recommended spacing is 4 feet longitudinally, and 18" transversely. The screw should be brass No. 12 x 3/4" round head, with an expansion shield if used in masonry. A large brass or copper washer, 1-1/4" diameter, should be placed under the screw head. The screw should be tightened sufficiently to keep the metal flat, but not restrict its movement. After the hold-down is in place, a 16 oz. copper cap should be soldered over the assembly to provide watertightness.

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7.1C. Expansion Cleats

Expansion cleats are typically used on long runs of standing seam roofing. Movement caused by thermal expansion and contraction is transmitted towards the ridge and eaves. Expansion cleats relieve the stresses that weaken the holding power of fixed cleats on long runs.

DWG iconDownload CAD File Copper Expansion Cleats

Two types of expansion cleats are shown. One utilizes a full-width sliding tab. The other is formed into a in "V", so that the cleat legs do not fold over onto each other. This reduces the build-up of copper material in the finished joint. Various other types of expansion cleats are available throughout the industry.

7.1D. Lock Strips

Two restraining methods are illustrated. Both are designed to prevent vertical wind uplift of roof pan edges, but allow horizontal expansion and contraction. The lock strip is a continuous strip usually of 20 oz. copper, soldered or fastened to a substrate. Its leading edge is raised to allow the end of a copper sheet to be locked over into a 3/4 inch lock.

DWG iconDownload CAD File Lock Strip

The double-fold is utilized in areas where conditions are limited in space. The copper base sheet is folded into a raised lip to allow the end of a "top sheet" to be locked over into a 3/4 inch lock.

DWG iconDownload CAD File Double-Fold Lock Strip