How To Flash Siding

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.

How to flash siding.

Then slip flashing behind the siding covering the top edge of the ledger. Fasten that shingle with two galvanized nails at the. At the top tuck metal drip cap flashing under the siding and on top of the second layer of wrap. Slip in the flashing.

However in most instances step flashing should be installed behind siding. Slice along the bend line about 4 inches into the first piece of flashing at the bottom of the roof with tin snips. In certain instances flashing may need to be installed on the exterior of siding. Many times builders fail to use proper flashing at the top of windows.

All flashings must integrate with adjacent materials so water always flows to the exterior following the shingle principle. Next comes another layer of building wrap installed like the first layer. Install the trim just under the drip cap. Slip flashing under siding snap a chalk line cut out the siding and tack up the ledger board.

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. Nail it to the sidewall or glue it if nailing isn t possible. Cut a piece. This has proven problematic over time as caulking the joint results in unsightly surface appearances due to the different textures as well as resulted.

Start by making an outline on the siding where you want to position the ledger board. When it comes to flashing siding corners many builders simply use a 1x wood corner. 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.

Inside corner w flashing. Lift the bottom shingle and slip in the kickout flashing. How to install step flashing under siding 1. Apply a bead of caulk to the felt and set the window in the caulk.

Cover with cap flashing. Where a slope roof meets a sidewall slip the upper legs of the step flashing under the sheathing wrap see illustration.