Tiling the outside of dormer windows is similar to tiling the roof because the dormer extends from the roof. Therefore, if the roof is tiled, it follows that the area around the window should also be tiled, to ensure that the roof looks uniform.
Step 1 - Prepare the Scaffolding
Build scaffolding for support during tile installation. The scaffolding should be wide enough to permit access to the entire surface of the dormer. It should also be sturdy enough to bear the weight of any person standing on it.
Step 2 – Do an Estimate
Measure the entire surface area to be tiled, and make an estimate on the number of tiles needed for the project, or ask a roof expert for an estimate given the surface area. Buy extra supplies just in case.
Step 3 – Prepare the Tiles
Make sure the tiles are the same as the ones installed on the roof. If the tiles are made of natural stone and supplies are limited or not available, there are concrete tiles made to look exactly like them. Before transporting the tiles onto the roof, cut tiles to fit the point where the dormer window meets the roof.
Step 4 – Install the Roofing Underlayment, Flashing, and Cant Strip
Read local codes to know what type of underlayment is required during roof tiling. Install the underlayment across the sheathing of the dormer window. Install the flashing on the valleys as well. Secure the cant strip, flush with the roof eaves.
Step 5 – Install the Tile Battens
From the roof eave, make marks on the underlayment for the battens. Determine the length of the entire tile and the recommended overhang. If the tile is 16 inches, and the overhang needs to be 1 inch for the first row of tiles, then the top edge of the first batten should be spaced 15 inches away from the eave. Mark the line with a chalk liner. For the succeeding battens, the spacing is a lot less (about 3 inches is required for the overhang). Therefore, if the tile is 16 inches, the succeeding spacing in between the batten lines should be 13 inches. Always follow the tile manufacturer’s recommendation. Nail the battens flush with the marked lines. Space the nails at least 12 inches away from each other.
Step 6 – Install the Tiles
Start tiling from the bottom of each side of the dormer window. Work from left to right when installing the tiles. Since the tile installation differs from one type of tile to another, it is important to read the manufacturer’s installation instructions before proceeding with the tiling process. Usually, two nails go into the top portion of the tiles. After tiling both sides, the top of the dormer window needs to be tiled using V-shaped tiles. The V-tiles also require mastic or mortar to ensure that water does not get into them.