What is the best way to lower the basement floor of 1920's bungalow??

Question

How should I do the transition between the new floor and the existing foundation walls? I don't mind digging, but I DO mind my foundation falling down.

I have what looks like a half basement/half crawl-space that was at some point dug out to make a full basement. About 850 sqft.

I've thought about jacking the house up, but I've been concerned with the house falling apart since it is old. If someone would do it for a couple thousand I would hire a contractor, but I am assuming it would be much more than that.

Answer 1

To lower your floor, first you need to explore what type of footings you have. If you get too close to them and disturb them by weakening the ground around them, (especially if you have stone), you could end up with a serious problem. The only way to lower the basement floor without risking a foundation problem is to raise the house. This isn't as hard as it sounds, as homes are held onto the foundation by gravity. There are companies that do this for you, usually house movers. Other than a professional, you can do it yourself using many car jacks, lolly colums and I-beams. Your local housing inspector will be All Over You no matter how you do it, as it should require a permit. We lifted our house 6 inches with no trouble, and built up the foundation to the sill level. It was fun, but slow going. To lift a house you need plenty of time - only an inch every few days - or you risk cracking a beam or the plaster. Also, remember to properly foot your lolly columns based on the frost line depth; 48" is always a good minimum.

Answer 2

This Site Might Help You.

RE:
What is the best way to lower the basement floor of 1920's bungalow??
How should I do the transition between the new floor and the existing foundation walls? I don't mind digging, but I DO mind my foundation falling down.

Answer 3

Lowering Basement Floor

Answer 4

We have the same type of house. At some point someone DID dig out a 3/4 height basement from a crawlspace (can you imagine? Like did they do it bucketful by bucketful, or what??)

It left a 2ft wide, 3ft high wall around the basement. It wasn't concreted properly- so isn't watertight, is damp, and is basically unusable. I'd have the house raised up before I'd recommend digging down, personally. A good chance to correct any sagging/settling problems, too- but you may have worse damage from the correction!

You may want to check into both options to see if there is a difference in price- and safety considerations. Everything should be done by a licensed contractor, with properly pulled permits!

Answer 5

I would say raise the ceiling and then the roof . For some reason who ever built the house decided to not dig down any deeper. I also would think that if you wanted to dig it out deeper you would have to do it from the outside in. If you really want a basement it might be far easier to do what we did. Instead of digging under the house we dug down where the carport was and built an enclosed stair case going down to the basement from the back door which also has a door to still go outside. So now my carport is now the roof of the basement. To do this tho you need a whole lot of rebar and cement so to hold up the weight of a couple cars or what ever. We have had it like this now for 15 years and not one car has fallen in yet. THis way you do no damage to your house and still get your basement.

Answer 6

May want to check out "Dry Basement " My parents had a company come out to ripped up the basement floor, put in a drainage system around the base of the floor, and the house jacked up. Second choice would be Lowes, Home Depot, or Handy Man Connetion.The house was built in 1928.

Answer 7

Sounds like you're going to have to jack up and move the house. Hey, if they can move the Cape Hatteras lighthouse, then your old bungalow shouldn't be a problem. Call a contractor and good luck!

Answer 8

If you want to keep existing foundation walls.....
One way to go would be to dig under existing foundation to depth required for footings in your area.
The foundation wall will be "hanging" in the dug out areas so the unsupported gaps should not be too wide
Supporting the house as you go with temporary columns.
Pour new footings then form & pour new sections of foundation wall close to level of existing wall or build up with concrete block.
There will be gaps between old & new which can be filled by ramming in drypack, a mixture of portland cement & barely moist sand, not sure anymore of proportions ( better research) , but it should form a crumbly ball when squeezed in your hand & stay in place when rammed.
This way avoids having to jack up the house & it can be done in manageable sections.
Once the new footings & walls are set, you can dig out the floor to required depth & pour new basement floor to new level per local code requirements.
Local inspector will advise if this method is acceptable
Good luck

Answer 9

Get an architect or engineer to map out what you need.
You will excavate on the inside of the existing foundation.
You may or may not need to shore up the existing foundation.
Essentially you will have a step at the foundation wall.
I know someone who did this and they are very very happy with it.
If you have young kids or plan a family you may consider radiant floor heating with either hot water or electric.

Answer 10

you have a good technical question. and you do have a couple of answers in your details. it is either up or down. up- jacking up is very expensive it all depends whether the upper part will withstand the jacking until new re-in forced foundations are poured it etc. expensive as you state.
the other option is down --it will be a very dark spot anyhow and the area is very small -- usage vs. hassle of doing the job is not worth it. if given the choice i will try to find new space outside of the house ==i.e. annexe to it and make it on a new stronger foundation. good work.