Q - My house sits over a 4 foot’ ish high crawlspace. I would love to add extra living space by digging out part of my crawl into a basement. I have the man power I need to knock it out in a weekend I think, but here is my question.
Do you recommend that I go to 8′ or 9′ ceilings in my new basement.
Phil in Grayson
A - Whooooaaaaaaa there partner.
Unless you have spoken with a foundation professional or a structural engineer and have been given the green light – and I would love to know which company you spoke with – you are getting way ahead of yourself.
I don’t recommend you dig at all.
If you dig 4′ down in your crawlspace you will likely be digging below your foundation - you know, the thing that holds your house up.
If you do not have a working knowledge of things like hydrostatic pressure, unbalanced backfill, and permanent lateral support (just to throw out a few issues here without going all Georgia Tech on you), then you could easily be placing the stability of your home - the part above the ground - the part you pay big money for - at risk.
Not to make light of you because I can understand how this looks like an attractive way to increase your square footage, this is not a do-it-yourself project.
Let’s, for the fun of it, look at some of the things which need to be done:
- your existing house needs to be supported every time you remove dirt…
- after digging, and removing by hand, the dirt, and supporting the house, you will need to re-foundation (I think I made that word up) the house, probably with block and mortar taking into account static pressures as well as hydrostatic…
- it will need to be water-proofed from the outside…
- your house will then no doubt go through a settling period which will be hard on the upstairs dry-wall, and doors I promise…
- you will need to pour flooring, add duct work, and an hvac system…
- One more thing here, I’m not sure how much digging = 1 weekend, but my guess is not as much as you think, especially if you think you are going to dig 4-5 ft down…
You can see the list is long (my list not nearly as extensive as a final list would be) and will be costly.
Do it yourself? Fact is, this is barely a ‘Let a Professional’ do it project, and it will cost you some big green.
If you proceed, I would love for you to call the show and tell me all about it. In fact, I would have you into the studio to discuss the process.
As for me though, I pass…