How To Install A Window Drip Cap
When you install windows, adding a drip cap to the window trim is essential. Since trim is exposed to the elements, it often gets wet, which lets water seep inside walls.
Replacing the rotted wood can become costly. Drip caps install on the top of the window to redirect water from the trim. Follow these steps to add a drip cap to window trim.
Prepare to Install the Drip Cap
To install the drip cap, you need :
- work gloves
- pry bar
- galvanized nails
- chisel or screwdriver
- borate
- hammer
- tin snips
- water-proof caulk
- caulk gun
- exterior-grade sealant
- wood epoxy resin
- flashing tape
- rubber mallet (optional)
- vise grips and wood blocks (optional)
- house wrap, felt, or roofing tar
Carefully pry siding slightly with the pry bar, and check for wood rot. If you notice wood rot, use a chisel or screwdriver to remove it.
Clean mold and mildew with borate. Don't touch mold with bare hands. Even if you don't find rot or mold, clean the area with borate.
Let the wood dry, then apply a wood epoxy resin where you removed wood to harden it. In some cases, you may need to replace the wood completely.
Measure for the Cap
Gently remove the siding above the window, lay it aside, and measure the window length. If you plan to install drip caps on multiple windows, measure the windows separately. Buy an aluminum or vinyl drip cap from a hardware store to fit the length.
Alternately, make your own aluminum drip cap from a sheet of aluminum. Secure the sheet with vise grips between two wood blocks, and use a mallet to bend it into shape.
Install the Drip Cap
Trim the drip cap to slightly longer than the window trim length. Attach the flashing tape over the trim, and insert the cap below the siding over it, and press it against the tape to secure.
Hammer the drip cap in place using the hammer and galvanized nails, sloping the cap slightly from the window to make an awning. Galvanized nails have a protective zinc coating which keeps them from rusting. After you hammer in all of the nails, cover them with roofing tar or felt.
Use the tin snips to trim the drip cap edges crosswise, and fold ends inward to keep rain from underneath the cap. Run a bead of exterior grade sealant along the drip cap edge. Reinstall the siding leaving a quarter-inch gap to keep water from the siding, and caulk the siding edges. Contact a company, like Unique Home Solutions, for more help.