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Make Crawl Space into Basement?

GotAll10's picture

I have a 50 year-old house.  Half of it has a full basement and half is crawl space with the same concrete walls as the rest of the basement and a concrete slab.  I don't know if the footings under the crawl space walls are the same depth as under the rest of the basement walls.

Has anyone ever converted a crawl space like this into a basement?  Obviously lots of dirt removal, probably a hole in the foundation.  Possible?  Stupid to try?  Expensive?

Thanks for any comments or suggestions.


(post #101243, reply #1 of 52)

Hate to be the one to burst your bubble, but the footings in the crawlspace won't be as deep as the ones for your basement, barring some very strange circumstances.  Most likely they'll be around the depth required to avoid frost, which varies from 1 to 4 or 5 feet deep in the lower 48 states.

Anyway, your choices are to remove all that too-shallow foundation and jack up the house and repour, or to pour new basement walls inside of the foundation stem-walls.  Not a real economical space in the end.

I guess with a concrete slab in the crawlspace you can't know exactly where the footings are, but they're probably right below the slab.


"so it goes"


"When we build, let us think that we build forever.  Let it not be for present delight nor for present use alone." --John Ruskin

"so it goes"


(post #101243, reply #2 of 52)

I have quite a bit of experience with this as I have been converting the crawlspace under my house (built in 1949) into a full basement for the last five years. I work gradually and with hand tools. So far, I've removed 4760 five-gallon buckets of hard clay. The full buckets weigh an average of 42 lbs.; so, I'm closing in on 200,000 lbs of material removed. In volume, it works out to 118 cubic yards of dug dirt, which I reckon is about 60 cubic yards of packed dirt. I carry the dirt off, 20 buckets at a time, in a 1989 Toyota pick-up truck. For me, this is sort of a hobby; I work on it when I have the time. I started on this project, dubbed the "Gacy Project" by my family, at the age of 52 and I'll be 57 this summer. I find the digging to be relaxing in the way that a gardener likes to dig in his garden. Sometimes, I find myself in my crawlspace when I really should be doing other things.

Three things that make this project doable are: the composition of the soil (clay, with no rocks); the ability to get rid of the soil (I've lined up numerous people who want it); and my masonry skills.

Is it worth it? In my neighborhood, I think it is. I live 5 blocks from Duke University and there is gentrification coming towards my house from two directions. I'm not only adding much-needed space to my house; I'm beefing up my foundation as I go. When the foundation's done, I plan on adding a second story to my house. I'll post some pictures anon.

(post #101243, reply #5 of 52)

Dude, I think you need a new hobby. All I can picture is you in your basement standing over a deep hole saying "It puts the lotion on the skin!"

(post #101243, reply #6 of 52)

"...4760 five-gallon buckets of hard clay..."

My hat's off to you, my friend.  That's a lot of dirt!

(post #101243, reply #7 of 52)

Here are before and after pictures taken in the same spot.

(post #101243, reply #17 of 52)

Very cool.

(post #101243, reply #8 of 52)

The wall I built here went under the center beam of the house. I poured a footing below the existing footing and came up with masonry.

(post #101243, reply #9 of 52)

After building the perpendicular wall, I've gone along under the existing footings in 40-48-inch sections. I dig out completely under the footing, pour a new footing, then bring up masonry to the underside of the old footing. I've done six or seven of these sections so far and have just about completed my first room in the basement.

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(post #101243, reply #15 of 52)


I'm in awe of your work, not enough that I'd do it myself but just the same!

What's the story on your house? How old is  it? Brick foundation doesnt seam that common to me, just curious.

I knew a guy that dug out his garage to add to the basement but he had 5 boys, your going solo I assume?


(post #101243, reply #18 of 52)

My house was built in 1949, the year I was born. Here in NC, brick foundations are very common. They are still being built, althought the inside wythe is usually block these days. I laid a brick foundation for a storage building last fall. Every house in my neighborhood, built from the 1920s to the 1950s, has an 8-inch thick brick foundation. My own house is a modest, wood-framed duplex. The foundation is 30-ft. by 60-ft. I am doing this solo.

(post #101243, reply #43 of 52)

Twofer here.  Needed to resurface this post so a friend could see it and was curious what you were up to.  Haven't seen posts from you in a while.  The house didn't fall on you, did it?


"In three words I can sum up everything I've learned about life: It goes on."

-- Robert Frost


Time is the coin of your life. It is the only coin you have, and only you can determine how it will be spent. Be careful lest you let other people spend it for you.
-- Carl Sandburg

(post #101243, reply #45 of 52)


(post #101243, reply #21 of 52)

Are you supporting the old footing all teh way to the backside of it or just to teh center (under the old wall)?


(post #101243, reply #23 of 52)

DoRight, Yes, the foundation is goes all the way back to the far side of the existing footing. The footing for the lower foundation extends 4 inches beyond. You might be able to see that in some of the photos. The total width of the footing is 32-in. and the total width of the lower foundation is 24-in. I'll have a 12-inch shelf inside the brick wall when I'm done. I've completed the shelf in some areas and I'll post some pictures of it. But, for now, I need to get back to work.

(post #101243, reply #10 of 52)

Sheeze, if you're spending that much time down there, I'd get the place tested for radon.   Whew!  I think I would have switched to a conveyor or Bobcat or something.  Sounds like 2400 trips up the steps with heavy-#### buckets to me.

I can remember watching some HGTV show where the dude was digging in his basement for 40 years or some such.  Had a multitude of tunnels everywhere.



"The difference between greatness and mediocrity is often how an individual views a mistake..."-- Nelson Boswell


Time is the coin of your life. It is the only coin you have, and only you can determine how it will be spent. Be careful lest you let other people spend it for you.
-- Carl Sandburg

(post #101243, reply #11 of 52)

> So far, I've removed 4760 five-gallon buckets of hard clay.

Wow.  I've removed maybe 300 - 500, never thought to keep count like that.  Mine's a crawl space that ranges from 36" in front to maybe about 8" (I can't get there to measure) in back.  So, I'm leaving the deep part alone, and deepening the rest to 18".  I built a sort of cart that holds three buckets in a row, with axles between them and 8" wheels.  The overhangs give me leverage to steer it with. 

You know, there are guys who pay money to go to a gym, pick up weights, and put them back down again.  We get to lift heavy buckets for free, you get a basement as part of the deal, and they think we're the crazy ones.  Go figure.  ;-)



-- J.S.




-- J.S.


(post #101243, reply #12 of 52)

I can't tell you how good it is to know there are others out there. Maybe we can start a support group. We could call it "Diggers Anonymous" or something like that. We are so misunderstood. 

(post #101243, reply #14 of 52)

Great job!

Like John said, sure beats paying to workout.

When I was 53 YO, needed to lose 40 # so dug out son's basement. Lost the 40 and gained 800 sq ft. Lots of rock, one 4 ft dia boulder - had to dig a hole below basement floor and roll it in wiht a couple of comealongs and chain. Did the stem wall thing 24 inches in, shelves on top the 'embankment" 

Count I kept was 167 wheelbarrows at 6 cu ft apiece, as 1/2 the house already had a daylight basement.

Gained 35 of the 40 back (a few times), so likely time to build something again.

Pop did the bucket thing when I was a kid, carried a few my self then. 

(post #101243, reply #19 of 52)

Junkhound, That was a clever way to dispose of that rock. I've been lucky so far but there's no guarentee that I won't run into aboulder at some time in this project. Here's a link to the story of one of my heroes:

(post #101243, reply #22 of 52)

Here's one for you, shame the pics aren't better:,,HGTV_3629_1391454,00.html




"The difference between greatness and mediocrity is often how an individual views a mistake..."-- Nelson Boswell


Time is the coin of your life. It is the only coin you have, and only you can determine how it will be spent. Be careful lest you let other people spend it for you.
-- Carl Sandburg

(post #101243, reply #31 of 52)

John, I enjoyed that link to the story about Baldasare Forestiere's underground home.

(post #101243, reply #46 of 52)

My project was modest by comparison: dug out crawl space, about 2' deep, to a depth of 8', but it was only 10' x 24'. Still, it was a lot of work.

A friend gave me a 4-inch-wide conveyor belt that reached 16', which I rigged up with an electric motor used to power the wheeled irrigation sprinkler lines that are used here in the dry West. When I had bucketed enough material out, I was able to set up this contraption to barely reach up out of the hole to the bed of my old 1970 Ford 3/4 ton pickup. I had to stop 3 or 4 times during each fill to go up and spread the dirt out in the pickup bed.

The conveyor I made with high side boards and cleats to carry the dirt up and out. Took 6 months of spare time to complete the excavation. I kept track of pickup loads, not bucketfuls, and I ended up with 65. Each load was the kind that makes your headlights shine up into the trees.

There's quite a bit of lava in our area, with projections of it showing above ground just across the street. I dug in fear that I would strike lava at a point that would render the whole effort as useless..., but, not so.

When it came time to begin building up the block foundation, I could not get the building permit until I submitted an engineered design to show how I would make it earthquake-proof, since we live in a D-2 seismic zone. Not too big of a deal, it just took some extra steel and concrete-filled cores to meet the need. The engineer only charged me $200 for the design.

Today, we have a really lovely wine/root/ham-curing cellar that brings me great pleasure every time I go down there, which is at least once a day. And the old Ford survived just fine.

I dismantled the conveyor, and gave my friend back his belt and motor.

(post #101243, reply #47 of 52)

I see you're about my age (59). While the digging and carrying is a bit hard on the old joints, the work is good exercise, isn't it? I've thought about getting a conveyor but that hasn't gotten beyond the dreaming stage. I also dream of getting a small dump truck.

My project continues. I've finished the first chamber, which is 12-ft. by 16-ft. It's ready for a concrete floor. This has been delayed by two things. Money and the fact that I'm away from home for the forseeable future, caring for my 86-year-old mother. She's blind and confused and my family is trying to keep her in the house that she's lived in for the last 29 years.

I've also dug out most of a larger second room. I need to find a month or so to finish that one up. The story of my life: I never have quite enough time or money to finish anything on my own house.

How about posting some pictures of your project!

(post #101243, reply #48 of 52)

I intend to put out some pictures when I get savvy enough to do it. I have a digital camera, but the limitations have nothing to do with hardware or software--it's me. The kinds of things I understand usually have wooden handles on them or carburetors.

I hope you keep up your strength for your toughest project--caring for your mother. God bless.

(post #101243, reply #51 of 52)

I hope you keep up your strength for your toughest project--caring for your mother. God bless.

Thanks. It has been a long haul but very gratifying.

(post #101243, reply #24 of 52)

Support?  I got a 12 ft. piece of w8x15 steel, and a bunch of cutoffs of 4"x8" to use for cribbing.  A couple bottle jacks to transfer the load, and some shims, and I can keep things well supported while I re-make parts of the foundation.

As for groups of us, I have a friend in Silverlake who did the whole dig out a basement thing, too.  I should look him up some time. 



-- J.S.




-- J.S.


(post #101243, reply #26 of 52)

Here's another attempt to provide a link to a story about one of the greats, Burro Schmidt:

(post #101243, reply #27 of 52)

People like this fascinate me.  I'm not sure why, maybe because it proves what can be accomplished with long-term dedication.

If my math is right, I figure Burro Schmidt moved about 1,000 lbs of rock per day, 7 days a week for 32 years.  That's pretty impressive, especially considering it was all done by hand.

Anyway, good luck with your basement.  I can see where you forum name comes from.


(post #101243, reply #28 of 52)

Here are a few more before and after pictures.

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(post #101243, reply #29 of 52)

Kinda cool!  Looks very substantial!  LOL!

How many sq ft will you have in basement when complete?