What is this access hole in basement slab?

9/1/2019 at 3:04:34 PM

Look's a little weird ... Can't say I've seen this before.. Maybe try to dig up some information on the previous home owner's an get to the bottom of this.. Maybe a old stash spot.

9/1/2019 at 3:23:08 PM

Hey James

Typically the wood access covers the backwater valve during pouring of basement slab sometimes they forget to extend the service pipe to top of grade of floor. Dig a little deeper simething should be their but I doubt that would be a tie in for plumbing that would require a venting stack close by as well

9/2/2019 at 4:41:43 PM

If You Dig Down one foot and do not find anything I would assume it was just an error on a mechanical end.

9/3/2019 at 7:08:14 PM

It could be meant for a stack for ventilating radon from underneath the basement slab.

Check to see what is above it. Would it be relatively easy to put a stack from that location up through the floors above and through the roof? If so I would guess that is what this is for.

9/3/2019 at 7:55:03 PM

It would be of interest to know how old the house is. Starting with the 2014 Alberta Building Code (which came into effect in 2015) radon provisions were added and it was required to embed a small piece of pipe in the concrete with a cap overtop and identified so people don't think it's a future drain. Beneath the concrete is supposed to be coarse granular as opposed to sand which was used before the new provisions (looks like coarse material in the photo).

As another respondent has mentioned it could also be a backwater valve beneath and it could be more than 1' down. Backwater valves are also required by today's Code.

10/12/2022 at 1:26:36 AM

I live in a house that was built in 1955 this basement has a hole in the foundation as well. Its all dirt. My roommate drains her dehumidifier in this hole. Dehumidifier keeps running. Dirt is really wet. Basement doesn't seem to have that much moisture for the dehumidifier to run all the time. Should we be draining dehumidifier into this hole?