Install Window Trim Before Or After Siding

From the top of this row and stretch a string line across the deck.

Install window trim before or after siding.

Cut the horizontal piece to size and snap it in place over the vertical moldings. We used pressure treated 2 x 4 s for the trim around the windows and the doorway and then we had to create trim corners for both the inside and the outside corners like the ones in the picture above. This increases the exterior wall thickness however so you ll need to extend the window. The wrb is lapped over the head flashing or the flashing is taped.

Instruction on how to install exterior 2x4 trim around a new or old window. The head flashing is installed in a bed of caulking onto the top of the window frame. The rain screen battens are run down to the top of the window flange. As long as the old siding isn t bulging or falling off you can usually install vinyl siding right over it.

If we installed the trim after the siding we would have had to caulk a ton to fill in for the different levels the layered siding creates. To provide a common reference point measure up 8 in. If the trim is being applied over the hardi panels. The cement board panels are fastened to the battens.

Before you replace the siding cut and install new j channels to prevent water from leaking into your home. Begin by installing the first row of siding on both sides of the deck.