Leveling Slab

[Dickey]

Due to all the dry weather the brick on my three thousand sq. foot house had cracked in several places so I called a contractor to get an estimate on leveling the slab. Twenty one thousand five hundred dollars is the estimate. Sure seems very high to me. I’m thinking about buying a backhoe and trying to do the job myself although I’ve never done any work like that. I sure could use some experienced advice.

 

[JJT]

Need more info, how old is the house? how big are the cracks? is the foundation cracking? was the house built on fill?

Sounds to me like you have a sub-standard foundation. Getting it level might be the least of your concerns.

How about some pictures?

 

[Paddy]

I have always wondered how a slab foundation would hold up over time. With this cost to fix, could have been built on a crawl space with poured walls.

Sorry to hear your troubles

 

[Chuck52]

Paddy,

As I understand modern building techniques, a slab foundation is still supported by piers of concrete which should extend below the local frost line at least. Our house was built in the mid 50's, and has a full basement under the main house and a 25x50 foot slab under the garage and laundry room. The slab part has settled over the years and we are getting both cracks in the brick work and in the walls and ceilings, especially in the part of the main house directly connected to the part on the slab. I got three estimates from companies which drive steel supports into the ground to lift the slab, RamJack is one of the national franchises, and all three came in at about $11K. They all said it would take 11 piers to raise and support the slab, and one of the reps did a vary thourough measurement job. He came up with about a 3-4 inch settlement at the lowest point, which agreed with my own calculations. The cost is about $1K per pier around here.

There's no way you could do the pier-type correction on your slab yourself. The equipment is too specialized and expensive. If you are thinking of mud-jacking, or something similar, again that might not be a DYI project. I doubt you could get under enough of the slab to raise it with house jacks without doing more damage than good, even if there were a place to position the jacks for support. I'd look into the RamJack-type fixes. Some folks swear by them; some swear at them. I suspect it depends on the soil type in your area. It seems to be the only way to go for my problem, and I plan to get it done this year. I'm tired of adjusting doors only to have them stick again in a few weeks/months.

Chuck

 

[EddieWalker]

Foundation repair is one of those specialized industries that has more issues than just about any other. You can't unbuild your house, so getting it fixed is your only option. I get calls on this all the time and refuse to even look at them, but I've been told stories by dozens of clients of foundation repair contractors comeing in, doing a bunch of work, and fixing the problem. But then the next year, it happens all over again. What's really disturbing isn't that most repairs don't work, but that these guys are not in business more than a few years and rarely return calls when the foundation starts to move again.

I don't know the answer or which system realy works. It's probably a locallized thing. In one are, one method might work, but in other areas, a different one will fix the problem.

My advice is to talk to everyone you can in your area. Be extra cautous of all of them, big national companies too.

Good luck,
Eddie

 

[Dickey]

The price was for fifty piers on four foot centers, I think they drill them into the ground ten or so feet deep so moisture is not so much a facter in this clay soil. Thank's for the input guys.

 

[Paddy]

When you say slab on piers, is there a continious beam at the parimeter conecting those piers?

If the piers are sinking, doesn't sound like they are frequent enough. I would think a continious below grade wall back filled would be the only way to have a soild base. In my area, only small track houses are on slab. I can't imagine a 3000' sq home of decent quality on a slab. A poured bacemnt costs only $12 a sq-ft after escavation. The poured wall act like a 8-10' tall beam. very stable.

 

[toolaholic]

I'm a ca gen contr. go to chance helical anchors on the net. you're about to get an education! we've used them for years! tool

 

[CurlyDave]

I'm a ca gen contr. go to chance helical anchors on the net. you're about to get an education! we've used them for years! tool

Wow!

That looks like the right way to do the job. How much does it cost?

 

[dmccarty]

Dickey,

Did the actual brick crack or was it the morter? Is it happen around the entire house or just in one locations?

Get and engineer to look at the problem and propose a fix. A coworker had a structural problem. He paid a couple hundred dollars for the engineer and his solution. The solution was a 4x4 and some concrete. I don't think you will be this lucky though.

I have never seen a slab built on piers. The way I have seen them built in is to just dig a 24 inch wide trench at least 12 inches deep and pour concrete for a footer. Build up a wall on the footer. The pad is poured inside the wall. In my area of NC the frost line is something like 6 inches so this works just fine. Because the frost line is so low basements are very expensive and very few people have them here. Most qoutes I got for a basement where around $40-50,000.

I would think the solution of the piers every four feet would defeat the expansive clay but I would get an engineer to look at the problem first.

Later,
Dan