Flashing Shed Roof Addition

Details concrete masonry roofing wrb flashing.

Flashing shed roof addition.

Flashing was added along that wall to keep the water out. Roof flashing is a thin material usually galvanized steel that professional roofers use to direct water away from critical areas of the roof wherever the roof plane meets a vertical surface like a wall or a dormer. Two ways to flash roof edges. Where a slope roof meets a sidewall slip the upper legs of the step flashing under the sheathing wrap see illustration.

Below we illustrate that using a single piece of metal flashing where the uppermost edge of a shed roof abuts a vertical building sidewall works fine though the use of exposed nails see our photo below may form leak or wear points in the roof. Click to enlarge make sure the sheathing wrap overlaps all step flashings. All flashings must integrate with adjacent materials so water always flows to the exterior following the shingle principle. Where snow buildup is likely add a wide band of peel and stick membrane lapped over the step flashing but under the sheathing wrap.

The new roof matched the slope of the shed roof but it tied in slightly lower on the wall to simplify the building process. One common method is to lay the edge metal under the eaves membrane and over the rake. Next the sheet siding for the addition was nailed directly to the studs to quickly enclose the space. Protect the eave from ice dams and sideways rain step one in steep slope roofing is the edge flashing.

Galvanized metal or aluminum is considered the best to use for roof flashing.