How To Seal Windows With Vinyl Siding

Often water leaks at a window result from a breakdown in the connection between the window frame and the wall.

How to seal windows with vinyl siding.

Remove the pieces of vinyl siding from around the window area. One of the somewhat more complex steps in the vinyl siding process however is installing it properly around windows. Vinyl siding by itself does not create a waterproof seal and care must be. If the window is surrounded by wood trim use a high grade polyurethane caulk to seal all gaps between the trim and the siding and the trim and the window.

Inspect the area above the leak including both indoors and out. Many vinyl siding installers do not realize the importance of the house wrap and its job as the sole water barrier because many people incorrectly. In this case the objects are the perimeter of the new exterior wall and the perimeter of the old open space. Caulk is used to seal spaces between two objects.

In this video this old house general contractor tom silva shows how to prevent water from leaking in behind vinyl siding. This prevents any air leakage. Caulking can be placed behind the j channel during installation sealing the seam between the j channel and the house wrap also sealing the seam between the j channel and the window itself. Smooth out the caulk.

But if done incorrectly it can lend a sloppy amateurish look. Vinyl siding installs in pieces so gaps and overlaps are normal. Check to be sure weep holes are open along bottom of window openings.