Roof Side Lap

Whenever one is installing a slate roof it is absolutely imperative the side lap is a minimum of 3 inches.

Roof side lap.

How a side lap joint works. Rolls and installs in the side lap of the roof and wall panels. This side lap tape sealant comes in 150 ft. 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.

Beginning at the roof edge measure one panel width and chalk a line from the ridge to the eave. Then situate the leading edge of the first panel along this line. The side lap also is referred to as a side joint vertical joint keyway bond line or rain course. However sealant along side laps is often omitted.

Make sure the panel is square to the roof line. The rolls can be easily cut to length. Roofing lap the amount by which roofing tiles slates shingles flashings etc overlap each other to achieve waterproofing. End lap refers to the amount of overlap in a direction following the roof slope.

As defined in the glossary of the nsa manual it s the longitudinal joint between two slate shingles. Side lap refers to the overlap in a sideways or horizontal direction. Side lap sealant is a self adhering foam tape. The use of sealant at end laps is a common practice unless the roof has a steep slope.

The absence of side lap sealant makes some roofs vulnerable to water intrusion which can have expensive conse quences. Why a side lap joint matters.