Window wells take a beating. They’re always exposed to the elements, are half-buried in the ground, and may even be affected by shifting, moving foundations. Over time, they can rust or warp and may even become detached from the home. When our homeowner wanted to spruce up her window wells, she called mason Mark McCullough for some help.
How to Replace a Window Well
- Measure and mark the areas you’ll excavate. If there are any fixed items nearby, measure their distance from the window well and match that distance on the other side of the window for aesthetic balance.
- Excavate the ground. If there’s a masonry or asphalt walkway in the way, use a circular saw with a masonry blade to cut across the surface in a straight line. Use the HEPA vacuum to clean up any dust and contaminants that may be released while cutting. Then, use a pickaxe or sledgehammer to break up the surface.
- Rake back any mulch or stone that you’ll be keeping, and lay a tarp down for catching soil. Dig down around the existing window well and unbolt it from the house before removing it from the ground.
- Dig about 10 inches below the bottom of where the old window well was. Fill this space with crushed stone and tamp it to pack it down.
- Measure the window and mark the centerline. Measure the width of the window well from the screw holes on one side to the screw holes on the other. Divide that number in half and measure this distance from the centerline of the window.
- Place the window well in the excavated pit outside the window. Line it up with the marks on either side of the window, and mark the exact locations of the bolt holes.
- Use a hammer drill and masonry bit to drill the mounting holes. Be sure to drill straight so the window well doesn’t shift or warp when it’s bolted.
- Insert the wedge anchor bolts through the screw holes of the window well, using a washer to prevent the nut from pulling through the bolt holes. Align the window well with the holes in the concrete foundation, and insert these anchors.
- Use a ratchet and socket to tighten up the bolts, adjusting the positioning of the window well as you go to ensure it remains level and centered.
- Backfill soil around the window well and tamp it down. If you removed mulch, you can now replace it. If you had to cut through asphalt or concrete, consider a masonry patch or a temporary solution until you’re able to renovate the surface.
Pro Tip: Mark, a This Old House general contractor, explains why this project matters: “One of the things [window wells] do is they’re going to help mitigate the water. They’re going to keep pests out. But they also let in light. It protects the window. I think that’s most important to me.”
When planning your window well installation, keep in mind that drainage is critical. According to This Old House Magazine, your contractor may need to include a drainpipe down to the footing drain, a deep gravel pit below the well, or even a dedicated dry well, depending on your site conditions. The landing area should also include a drain, and the outside wall of the well must be at least 3 feet from the foundation wall to satisfy building code.
Materials
Pro Tip: As Mark explained during the project, the wedge anchor bolts feature a sleeve that expands as you tighten the nut with a ratchet. “This sleeve is going to expand. So it’s going to grab that hole and we’re not going to be able to get it out,” he noted. This ensures the window well is permanently and securely fastened to the concrete foundation.
