In anticipation of putting a second story on the house, I started investigating my existing foundation footing (some of you may have read my post the other day). My house is about 2/3 basement and 1/3 crawlspace (the lot slopes so I get a walk out basement and they stopped digging when they hit too much dirt).
Because the crawlspace foundation is probably not functional for a second story, I think I’m gonna just dig it out and make it match up with my existing basement. Anybody have any experience with this sort of thing? Any pointers on general approach would be great. Mostly I’m looking for some people who have done or seen it done and will say “yes, it’s doable, go for it” or “forget it’s just too much”. I’ll be recovering about 500 sq ft of space that will be added to my workshop (yeah, you always need more shop space right…?). If I can do it for $15k (which I think I can), that will be $30/sq ft.
I have an engineer involved and I’ve talked to several contractors about the project (a mason, a foundation guy, and another guy with highly recommended bobcat skills). All of them seem to think it’s completely doable though it will require some good coordination (which I agree).
Replies
>> Because the crawlspace foundation is probably not functional for a second story ...
I'd get an expert opinion on that before I made any decisions. Unless the house is really old, I suspect the foundation will handle a second story just fine.
I agree w/ "Uncle Dunc" about the foundation...Typical one story would have you do a 6" x 12" w/ a 6" thk. wall, and 7" x 15' w/ a 8" thk. wall for a two story...BUT..I understand and know if the foundation is in good shape you may want to save a few $$ and leave it alone. And of course the other issue is how much additional loads your design may place on it....A good engineer will be able to run the ##. Jurisdiction may challenge you..if they do just tell them to chill, look@ the calcs' while eating their donuts, but the challenge may be worth the savings.
Sounds to me like you are talking about two different kinds of space....one, a second story addition for more living area OR two, expanding your basement workshop by 500 sqft. So what space do you need...or is A) part of your shop taking up half the DW's kitchen upstairs, or B) are you just itching to add something/spend money?
Just wondering
Go for it!
My case sounds like yours.
Made new door in wall to area to be dug out, covered carpet with plywood and poly so could go straight out back door with wheelbarrows 50 ft downhill.
400 sq feet with 6 ft deep dirt, roughly 80 yards of dirt to move, 6 cu ft per wheelbarrow, did a little over 2 yards a day with pick and shovel 'for exercise' for just over a month, all dug out, side benefit lost 10 pounds of fat.
Left 1 ft embankment of dirt (compated hardpan), then forms to cover with concrete out to 2 feet with rebar tied into existing footing.
Result leaves a 2 foot bench for shelves/counter to be built above. 4" concrete floor with drains inside new embankment, insulated wood sleeper floor above concrete.
Total cost for 400 sq feet additional space (with much surplus lumber used) was less than $5 sq foot, of which $700 was concrete and $300 carpet. .
I'll try to address most of the questions. I'm doing a large remodel. Tearing off the roof (4/12) and first floor ceiling, building a new flooring system, and the putting on a 12/12 roof. A good part of the first floor is being reorganized. 2/3 of the house is over a basement with very good walls (8" block w/ brick veneer) and best I can tell a good footing buried about 30" below basement floor (I'm in NC, so plenty deep). However, crawlspace footing not so good (I posted a picture a few days ago...http://forums.prospero.com/tp-breaktime/messages/?msg=35522.1). It really looks like they threw rubble in a hole with some mortar and started hogging with brick. During this remodel I'm also tearing off the screen porch, driveway and front porch, which makes up 3 of 4 sides of the crawlspace (the other side borders the basement). So now is the time to do it and I'm going to have all the big equipment around.
Other choice is to have the engineer pronounce the footing no good and have it underpinned at the cost of ...? I don't know. I was thinking I might as well just bite the bullet and get a 500 sq ft addition to the shop while I'm spending freely on everything else.
Ah, this brings back memories...I used to do this kind of work, always by hand - usually had to push wheelbarrow up to floor height to get out of the basement.
It is a LOT of work, but used to be able to do it very cheaply and make quite a bit of money (that is a relative term, but to me it was a lot of money at the time). I always thought the worst part of the job was pouring the footings. Never seemed like we could get the concrete truck close enough, and we ended up taking wheelbarrows full of concrete DOWN into the basement. Or lowering 5 gallon buckets into the basement. What a pain....
Ah, the memories... :~)
Jamie
I'm with Junkhound.
I did it also. In my case, a coupla of places I had to dig out under existing footings to extend them further down. The rest of the area, I built a stem wall inside of the existing footing/foundation (about 24 inches inside and not disturbing the soil under the footings. The stem wall was built on good solid footings of their own. Backfilled in a bit and poured concrete flush with the top of the original footing. This allowed a bit of a bench around the wall.
But as Junkhound said, a lot of hand digging, a lot of wheelbarrowing, and a lot of effort. I wasn't so lucky to be able to go downhill. I had to wheel each barrow about a 150 to 200 feet out to the back of the lot. Took me about six months off and on.
Then had to wheelbarrow in about 8 yards of 60/40 so's I could mix the concrete right there in the new basement area.
Cost me about $150 for the gravel, same for the cement, 100 for the concrete blocks for the stemwall, and about 50 for the drain pipes.
Relatively cheep for the added 400 sq. ft of basement.
Did I say it was a lot of work?
Do you have any idea what's down there? I mean bedrock, clay, virgin soil (of what type), etc?
I've done various jobs like this, some with complete removal of the soil and foundation with a skid loader, our current home with pick, shovel, buckets, and SONS!
Foundation thickness depends on local code and soils. There is no general answer.
Any jackass can kick down a barn, but it takes a carpenter to build one.
A belt conveyor is the way to move the soil out of the mine . Its a no brainer an added 500 sq.ft. of shop space. Has to be done even if the foundation is good.