Skip to main content
Stesso

Apply Sealant to Window Flange

1:29
2:59
15.1M views

At 1:29 in

Learn window and flashing installation. Learn how to keep the water out💪 #window #flashing #learn

Watch on YouTube

What happens here

Apply a bead of sealant to the back of the window's nailing flange. Crucially, sealant should only be applied to the top and side nailing flanges, positioned just below the nailing holes. Never apply sealant to the bottom nailing flange. Sealing the bottom flange can trap any water that gets behind the window, preventing it from draining out through the weep holes and potentially causing water damage inside the house.

Goal: Seal the window's top and side flanges for air and water sealing, avoiding the bottom.

Tools and materials

  • Caulk Gun N/A — Dispensing sealant
  • Sealant Lexel — Creating an air and water seal between the window flange and the WRB
  • Water Sprayer N/A — Demonstrating water trapping if sealant is applied incorrectly
  • Window BAS Window — The window to be sealed

What they say

Hide

if it's on the top, water can flow down and potentially trap water. Now I'll add a bead of sealant. I like to put this on decent right below the nailing. It's a great idea to put sealant on the top and the sides of a window. You never want to put sealant on the bottom. If you were to seal this bottom edge, when your window gets installed, it can cause water to get trapped in this space, and this can run back into your house. This is another good reason to pitch your sill or use a sill flashing. Now we'll install the window level and

Auto-generated from the video audio.