Cutting and enlarging foundation openings
The cut is the part of the job you can't undo. Here's how installers handle the different foundation walls found around Duluth.
An egress opening is almost always bigger than the window that was there before, and usually deeper, since the sill has to come down to within 44 inches of the floor. That means removing a section of foundation wall and making sure the house above is still properly supported.
How are different walls cut?
- Poured concrete. A track- or hand-mounted diamond wall saw cuts clean edges. Water keeps the dust down. The opening is usually framed with treated lumber or a metal buck.
- Concrete block. Blocks are cut or removed, and the open cores at the sides are filled so the edges are solid. A lintel over the top carries the courses above.
- Brick and stone. Many older Duluth homes have rubble stone or brick foundations. These need more care: loose stone can shift when a section is removed, and the installer should explain how the wall will be shored and the opening edges rebuilt.
Does the opening need a header?
Often. If the cut runs up toward the sill plate or interrupts a wall carrying a beam, floor joists or a bearing wall, the load above has to be transferred around the opening. An installer may add a steel or wood header, or recommend an engineer when the wall or the load is unusual. Duluth's basement-finishing handout asks permit applicants to identify bearing walls and show which way joists run, which gives the inspector the same information.
Enlarging an existing window
Swapping in a new window the same size as the old one doesn't make a bedroom legal. Minnesota's code lets a replacement window skip the size and sill rules only when it's the largest standard size that fits the existing frame and has the same or a better operating style, and that exemption doesn't apply when the room's use is changing. If you're turning a storage room into a bedroom, plan on cutting the opening bigger and lower.
What about mess and dust?
- Wet cutting produces slurry; ask how it will be contained
- Move furniture and cover anything near the wall inside
- Ask whether the installer hauls away the cut concrete and soil
The installer prices the job after seeing the wall, the yard outside it and the room inside. We don't quote prices, and a number given over the phone before anyone has looked at the foundation is only a rough starting point.
Where we connect you with help
Common questions
Will cutting an egress opening crack my foundation?
A properly planned cut with support above it shouldn't. Ask how the installer will handle the load and the cut edges, and whether an engineer is needed for your wall.
Can an opening be cut in a stone foundation?
Often, yes, but it takes more shoring and rebuilding than poured concrete. Ask installers whether they've worked on stone walls and how they rebuild the opening's sides.
Related services
- Egress window installation
- Window wells and ladders
- Window well covers
- Basement bedroom code compliance
More background: Duluth egress window guide.
Finishing the basement or adding a bedroom down there?
Call now and a local egress installer will look at the wall and quote the opening, the window and the well.