How To Install Vinyl Siding Around A Window

1 October 2018
 Categories: Construction & Contractors, Blog


Whether you are installing vinyl siding for the first time or have replaced a window and now need to reinstall existing vinyl siding around it, these steps describe how to do so while protecting your home from unwanted water intrusion in the future:

Step 1: Seal the Window's Nailing Flange with a Waterproof Exterior-Grade Sealant 

The more you seal around windows, the less chance they will ever leak water and cause dry rot or mold growth.

Sealing a window correctly for siding installation starts with sealing its nailing flange with a waterproof sealant. Using a tube of exterior-grade sealant and a caulking gun, apply a thick bead of sealant over the top of each nailing strip on all four sides of the window.

Step 2: Install Self-Adhesive Window Flashing Material Around the Window

Without allowing the sealant to dry, you need to install flashing material on top of it. The easiest way to do so is to use a self-adhesive flashing.

Cut four strips of flashing that are each about a foot longer than the side of the window where they will be installed.

Starting with the bottom and then moving to the sides followed by the top, install each strip of flashing directly over the adhesive. Line up the flashing with the edge of the window and staple it in place with galvanized staples.

Step 3: Install the Vinyl Siding's J-Channel Around the Window

Once the flashing is all stapled in place, you need to install j-channel around the bottom and sides of the window.

Starting with the bottom section, cut the j-channel to size using tin snips or a utility knife. Cut notches in each end so you can slot together the sides when you install them next. 

Step 4: Install a Drip Cap on the Top of the Window

Once the j-channel has all been installed, then top the window by installing a drip cap piece. The drip cap prevents water from intruding under the siding and into the window's flange where it could cause dry rot. Cut the drip cap in the same way as the j-channels and slot everything together.

Step 5: Install the Vinyl Siding

Now that you have correctly prepared the area around the window for the vinyl siding installation it's time to put the siding in place. When nailing each strip of siding, use galvanized nails and nail it gently enough the nail heads stick up a bit and the siding strips can still slide back and forth to allow for expansion and contraction in the weather. Don't pound the nail heads all the way flat to the flashing or the siding strips will crack when they are unable to shrink and expand as the outdoor temperatures change.

Reach out to a place like Superior Products for more information. 


Share