I’m building an exterior entrance to my basement and had a question about cutting the opening in my foundation. It is a poured foundation.
Can I cut the entrance through the foundation entirely down to the footing, or should I leave a foot of the foundation intact at the bottom? I’ve seen both done. Is leaving that 1 foot maintaining any sort of structural purpose? I could see leaving it for moisture reasons so the door isn’t sitting in water, but in my situation the entrance is covered with a roof, walls, and a door. I would be cutting the foundation entrance into an existing window, so there would be no concrete above the entrance either, just a lintel.
I made two images attached, describing the two foundation cuts.
Thanks.
Replies
According to your drawings, you are not cutting through or even down to your footing. Instead, you are cutting a foot above or down to the SLAB. The footing is below the slab and its depth varies according to frost depth in the area.
You will be cutting through concrete and rebar.
You are proposing cutting at an existing window location, so a lintel also exists. That's great, but keep in mind, you cannot widen the door more than the width of the existing window - not even an inch - concrete to concrete.
Will the new door be raised above grade - outside, at the approach to the new opening? If, then you don't need a curb at the new opening and you can cut clear down to the slab. Think in terms of keeping water out. There is no structural purpose of the wall below the lintel, down to the slab - in this situation.
Frankie
Hi Frankie, thanks for the response. The landing of the new entrance will have a slab poured flush with the existing basement slab, and so the cut in the new foundation entrance would indeed only reach the existing slab. Will be hiring out the cutting for sure.
Yes - the new door will be 6" above grade at the approach to the new opening. Thanks for verifying a curb at the new opening wouldn't be necessary.