Flashing Under Cedar Siding

Flashing must be overlapped by the moisture barrier.

Flashing under cedar siding. How to install step flashing under siding. Step flashing is used where a roof meets a. Add felt if needed before nailing the new wood on and prime the new wood on all. The top of the step flashing is still under the siding or plaster.

We only caulk butt joints on cedar siding if previously caulked. If the kick out and step flashing can t tuck behind the siding screw on cap flashing to cover it then caulk along the top. Put the bottom step flashing on the starter course then bend the bottom of the step flashing out about 1 to 1 away from the wall. Natural siding boards are designed to expand and contract with the elements and we do not want any adhesive to prevent their natural movement.

Flashing intercepts and directs the flow of water away from the building to designed drainage paths. A common problem with cement board siding products and some other types of horizontal lap siding is that older installation guidelines called for caulking the joint instead of flashing the joint. Otherwise it is possible for water to wick up the shingles and into the wall. Before installing siding make sure that flashings are installed to prevent moisture from entering wall and roof spaces.

It is always recommended to install step flashing behind stucco dryvit wood panel lap siding vinyl siding cedar shingle siding etc. Cedar shingle siding must never rest on the horizontal surface of flashing. Step flashings on a cedar shake roof are typically installed every 10 inches. Inspect the sidewall around and underneath the fascia and inside the house for signs of moisture damage and repair any rotted areas.

Failing to replace step flashings when a cedar shake roof is replaced with a composition shingle roof. Keep water out of your home and running down the roof where it belongs with appropriate use of step flashing. Use a felt paper spline wrapped around the corner and extending 6 inches beyond the corner board to protect the joints where the siding meets the corner boards see figure 1 5 at left. Building siding flashing finish details for building corners use overlapping 1x4s or 1x6s at outside corners or use 5 4 stock for a heavier look.

Flashing is an important line of defense in controlling moisture in wall assemblies. Fiber cement boards are caulked only when there is no metal flashing behind them. Flashing should be made from a non corrosive material and should extend a minimum of 2 vertically up the wall.