Crumbling Foundation

[gbick]

Recently, after a hard rain, I noticed "rabbit holes" next to the cement block foundation. Digging down to investigate, I found the outside of the blocks crumbled away below grade and the dirt was falling into the hollows. The blocks look fine from inside and above ground outside.
The house is "L" shaped The original section is over 100yrs old, 2 story with cellar and full stone foundation. It is in fine shape. The 1 story problem section was added on in the 70's. It sits over a dirt crawlspace. The block frostwall was never sealed on the outside and the paved driveway slopes right to it. The backyard also slopes toward the house. (The JD 4310 will remedy this.)
The immediate issue is to replace this foundation before that part of the house falls. Lifting the whole house is out of the question and as they are connected, this section can't be lifted much. The plan is to knock out and replace the blocks a small section at a time. This, I can afford and and can work as I can. Not having laid block before, I'm wondering how to get the blocks hard up against the sill. Should anything go between the blocks and the sill?
I was wondering how I would ever get the time to do this. Well be careful what you wish for- the paper mill I've worked at for 22yrs. suddenly shut down last week. I could lament about America's evaporating industry, but that's a different thread. I will be paid for 60 days or until called back by a different owner. If the mill isn't sold by then, GP will close it permenantly. So I will be starting on this job right away. Any advice, guys and girls? Thanks, Greg.

 

[Marlowe]

I don't have a real clear picture in my mind of your problem, but I think that you have an issue with freeze damage. I'm not at all experienced with that problem, being a southern redneck. It would seem to me though that a fix would involve digging deeper. If you go deep enough you will get below the frost line. The good news is that it seems you will have enough time on your hands to do this. The bad news is that you may not have enough money to pay for it. I've had that problem all my life. The best support I can give you in that regard is that sometimes the worst news turns out to be the best. Hang in there.

Tom

 

[MotorSeven]

gbick,

Got any pic's?
I recently did a re-mod on a house we bought in Manitoba. The add-on(vintage 1940ish) 9x30 rear room had a 5.5" slant in the floor........yep, on the 9' wide part. The foundation wall had crumbled and the exterior wall had sunk. I couldn't jack the wall up, because the moron previous owner had put a really nice steel roof over the sagging roof /forums/images/graemlins/confused.gif. So, i dug a trench along the outside foundation wall and built a form that would completly encompass the old wall-approx 30'longx2'x4' . We poured 6.5 yards of crete. I still had rip out the original floor and lower the joists at the house side to get the darn floor even close to level.
Sorry for the long explanation, but i think you may be able to do something along those lines- form up and re-pour along the outside existing wall......
BTW- get rid of those "Crete Rabbits" , i bet they even tast gritty /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif!

RD

 

[TOL1488]

There is another thread involving this somewhere on this board, I stumbled across it before but can't find it right now. Good luck all the same and remember the pictures.

As for the "evaporating industry" that just comes from a lack of support. Many people are only interested in getting things as cheap as they possibly can lets hope they keep the pennies they save for the language lessons their children will need to survive. As is there is no motivation for even American companies to employ Americans as most obviously don't care.

 

[Egon]

You could replace small portions at a time and slowly work your way to completion. Use grout for the very top layer to get full support. For this I would sugest an epoxy type mixture.

The original blocks may have failed due to phosphates.

Surely hope you employment future turns for the better.

Egon

 

[megotatractor]

I face a similar situation. the main house built 1900 is a 1 3/4 story approx 25'x35' with stone foundation over a crawl space and root cellar in one corner. the corner with the cellar has not settled as much as the rest of the house so the kitchen floor is extremely slanted. then about 1985 some moron brought in a 18'x30' office section -converted to a living room -and parked it next to the original house with the eaves just butted against the house. it is set on posts and beams. then stupid build a new roof over the original roof to eliminate where the original would have sloped towards the house. now the beams underneath were positioned like a trailer house at 1/3 point but the building was origninally on some kind of foundation. So with the weight of two compete roofs the walls have no support other than the floor and have settled a good 4" at the side walls causing the floor to bow up in the middle. makes for drunken walking sometimes. so i'm looking at trenching along those outer walls and building some sort of footing to support the walls. once jacked up level no doubt this is going to disturb the siding and roof (can't think what it's called, the metal the runs along the wall where the addition roof meets). but since the original house has a foundation that is no longer true perhaps Im' considering just trashing the "addition" and having the house jacke up and moved onto a new basement. whatcha think?

 

[Rob_H]

Hey gbick;

Sorry to hear about your employment situation, you can't really count on anything anymore.

I just posted to Megotatractor's thread about a similar problem. As I said on that thread, we've done a partial foundation replacement on our old place (1767 / 1851) due to settling / collapse.

You will need to jack the house a little - 1/2 to 1" for two reasons, you need to take the load off the current foundation in order to remove / replace it. You also need to lift the house so you can set it back down and have full contact with the new foundation. This is true whether you are replacing the block wall or pouring an additional foundation outside it - you still need the contact with the sills.

Don't worry about jacking the house too much. There is a surprising amount of flexibility in a structure, and 1/2 to 1" along an entire wall probably won't mess up the roof connection, and may not even crack the plaster. We've jacked our house several times - to replace sills on three sides, to replace the foundation wall mentioned, and to get the sag out of the 28' timbers that had no center support. Since we're gutting the interior anyway, we weren't careful about how we jacked the house. The only places that gave were the corners where an interior wall met an exterior wall. If we were keeping the plaster, these would be a simple fix.

I recommend you get the book Renovating old houses by George Nash. He has a chapter on foundation repair / replacement that should give you some ideas.

Good luck, and keep us informed.

Rob H