How to Install a New Construction Window the Right Way
The number one enemy of your house is water, and I’m a constant crusader on the topic of water management. My guess is that 90+% of all windows installed in American homes have no sill pan under them. We as a building community are placing huge faith in these flanged windows that they will never develop a leak when we install them into a hole and tape the flanges then move on with cladding.
Windows can & will leak, so this install method you’ll see here I feel is the best practice method for installing a flanged window in new construction. I like that this method utilizes off the shelf products and is easily trainable. I actually use this video as I’m training new carpenters who join our crew.
Here’s an overview of the steps covered in the video for how to install a new construction window:
- Put down the sill pan (FlexWrap is recommended if you can spare the extra cash).
- Put down three horseshoe shims on the sill.
- Caulk the window on three sides (not the sill!).
- Place the window and nail off the flanges at the top.
- Before nailing on the bottom flange, pop a shim under every other nail hole and nail through the shim, giving the water an escape path for whenever the inevitable leak does occur.
- Finish nailing down the flanges on all sides.
- Wrap the sides, then the head of the window, leaving the sill open.
- Tack down the wrap that was flipped up, cut it flush to the window head, and then finally put a piece of Tyvek tape over the corners. This should be your last step in installing a new construction window.
– Matt Risinger