Roof Side Lap

The use of sealant at end laps is a common practice unless the roof has a steep slope.

Roof side lap.

When two pieces of metal deck with the same profile are adjacent a side lap joint can be used to fasten the two sheets together by overlapping a portion of each sheet by using a side lap fastener. Side lap sealant is a self adhering foam tape. Rolls and installs in the side lap of the roof and wall panels. As defined in the glossary of the nsa manual it s the longitudinal joint between two slate shingles.

The side lap also is referred to as a side joint vertical joint keyway bond line or rain course. Beginning at the roof edge measure one panel width and chalk a line from the ridge to the eave. On the eave side of the roof aim to overhang the panels by 1 to 1 5 inches. However sealant along side laps is often omitted.

This side lap tape sealant comes in 150 ft. Side lap refers to the overlap in a sideways or horizontal direction. Make sure the panel is square to the roof line. Flexible foam that is uv resistant and won t scratch the paint.

Whenever one is installing a slate roof it is absolutely imperative the side lap is a minimum of 3 inches. Roofing lap the amount by which roofing tiles slates shingles flashings etc overlap each other to achieve waterproofing. The absence of side lap sealant makes some roofs vulnerable to water intrusion which can have expensive conse quences. Adhesive on one side allows the tape to remain in place while installing it.

The rolls can be easily cut to length. Why a side lap joint matters.