Foundation cutting and enlarging openings
The structural part of an egress job: cutting through the foundation wall and making sure the house above is still properly supported.
Your foundation carries the weight of the house. When an installer cuts a bigger hole in it, that load has to be carried around the opening by a header or lintel. That's why foundation cutting needs a permit, and why it's not a weekend project.
How is a poured concrete wall cut?
Poured walls are usually cut with a large walk-behind or track-mounted saw, often with water to control dust. The cut is made from both sides, the block of concrete is broken out and removed, and the edges are cleaned up for the window buck. If the opening is wider than the old window, a header or steel lintel may be added above it. Rebar exposed in the cut is typically sealed or coated.
What about concrete block?
Block walls are common in La Crosse homes built in the middle of the last century. Cutting block opens the hollow cores, so the installer fills the cores at the sides of the opening with concrete, or caps them, and sets a lintel over the top. Block walls that already lean or have a long horizontal crack should be evaluated before anyone cuts them.
And stone or brick foundations?
Some of the oldest homes near downtown and on the Northside sit on limestone, sandstone or brick foundations. These walls weren't built with large openings in mind. Some can take an egress window with a properly designed lintel and careful rebuilding of the masonry around it, and some are better left alone in favor of a different wall or a bedroom upstairs. Expect the contractor to be cautious, and possibly to suggest an engineer.
Signs the wall needs a closer look first
- A horizontal crack running along the wall where you want the window
- A wall that bows inward or has shifted at the top
- Water coming through the wall or the floor joint every spring
- Crumbling mortar or loose stones
- An addition, deck footing or chimney sitting right above the spot
Dust, noise and cleanup
Wet cutting keeps most dust down, but it creates slurry. Ask how the installer protects the inside of the basement, how long the saw will run, and where the cut concrete goes.
The installer prices the job after measuring the room, looking at the wall from both sides and checking what's buried along the foundation. We don't quote prices, and any number you hear over the phone before someone sees the basement is only a rough starting point.
Where we connect you with help
Common questions
Do I need an engineer to cut my foundation?
It depends on the wall, the opening size and your permit office. Many standard openings in poured walls are handled with a prescribed header. Wide openings, damaged walls and stone foundations are where an engineer is more likely to be involved.
Will cutting an opening weaken my house?
Not when the opening is supported correctly. The header or lintel carries the load that the removed concrete used to carry, and the inspector checks it before the job is closed up.
Related services
More background: La Crosse egress window guide.
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