Foundation Cracked And Settling

wackman

This isn't my thing but my vet (who's done a lot of work for me this last year) asked me to come take a look at her house, that it's dropping.

Sure enough there's a big crack on the two parallel walls of her foundation and it's settled quite a bit, about 1 1/2" slope in 8'. The crack is on both walls in the same place, where the partial basement stops and the retaining wall runs through. Right on the other side of this and where the normal foundation wall starts is where both cracks are. The cracks are about 1/4"-3/8" in the basement and 1/8" on the outside.

This home was built in the 20s and it was poured with sand and rocks staight out of the local river, I've found sea shells inside these foundations when cutting concrete for egress windows and it's not too good looking now. It's spawling a bit and you can tell it wasn't a good mix with lots of rock showing and little cement.

What's the standard fix for this settling?

Dik Redi

thats a good 1

Chris Johnson

My educated guess would be the foundation is shot, poorly built 80-90 years and still somewhat surviving. Is it leaking through the cracks? I would probably sell them on replacing the footings/foundation if it is that poor a condition, I would be afraid to do epoxy injection in the cracks, they will be 100 times stronger than the surounding concrete (sand/river rock/sea shells, etc)

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Chris

stacker

perma jack and about $50,000

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life is short,do your masonry naked!!
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wackman

The majority of the foundation looks ok, especially in the basement part of. It really only looks bad in a few spots, and a couple of those spots happen to be these weak spots in the foundation. It almost looks like a different pour but there's no cold joint so I'm assuming it was just a bad batch during the pour.

I thought about using some of those seismic movement straps that you attach on each side of the crack to see if this is still moving or if it's old and just now getting noticed. If it's not moving anymore then I'd just tell her to fill the crack.

Epoxy's not strong enough to stop the settling is it? I always understood it to be really for just filling the crack and that some additional measures were needed for the settling.

What's perma jack?

jvcstone

Sometimes in the "right"soil conditions--expansive clays in particular, cracks will open and close depending on the long term weather patterns and soil moisture content. Patching a crack under this sort of condition can create even more damage. Get a stuctural engineer to look at it.
JVC

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John VanCamp
www.jvcstoneworks.com

stacker

perma jack is a company that comes in and drill down to bedrock and jacks the foundation back to normal.then use steel piers to stablize the foundation.

http://www.permajack.com

__________________
life is short,do your masonry naked!!
http://ok.local.yahoo.biz/knabemasonry/index.html

ch0mpie

No get a geotechnical engineer

stackers got the right idea, if the foundation is in ok shape then it is a soils problem. You need to dig down to competent material and underpin the footings. I would check the price of perma jack versus doing standard underpinning. May only need to underpin a few feet below the existing foundation level instead of going to bedrock for a house which is relatively lightly load. It also depends on the footing width. However, you will probably need to do a test pit and maybe a boring to determine all of this.

wackman

Boy, she's not gonna like this news. I told her not to worry too much about it till I did a little research and really nailed down what she's up against.

Sounds to me like it probably wasn't poured on virgin dirt and it wasn't compacted properly. Her house is on a built up area and the foundation is good except for this. I'll have my geotech take a look at it and see what they suggest to do next.

With the regular underpinnings, what all does that usually entail?

denick

Wack,

We have fixed quite a few old foundaton like you have described. To establish what has happened and when. If the house was built in the 20's and the settling happened in the 30's it makes a lot of difference.

What is happening in the upstairs? Are the walls cracking? is the floor buckling? are the windows out of square? Have things been like this a long time? or is there new movement? What about underneath the floor system? If things are out out kilter but the paint is good and no cracks it should show this happened a while ago.

When you look at the cracks in the basement are the edges sharp and hard? or are they full of dust and powdery material?

I have been asked to look at foundations in two instances where people were selling houses and the home inspector said the foundations needed "repair or replacement". Potential buyers brought in engineers that stated that the work needed to be done would be very extensive. We looked at the walls but noticed both houses were near perfect in condition inside and outside and underneath. Some repair and buttressing and the foundations would be fine for the load of the existing house. As chompie said there isn't much weight in a normal house load.

The buyers were people with money in both cases and the sellers were elderly people who needed to sell. When one of the engineers called to tell us to stick to are own business we asked him to meet on site and sign a letter to the fact that the house was unstable. After telling him what we observed he never called back.

Do you have pictures?

__________________
Nick

"Every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving" Albert Einstein

ch0mpie

underpinning ussually is done by excavating down to foundation level, and digging a pit about 4ft wide and the entire width of the footing under the footing to competant material. Once the pit is filled with concrete, the footing is jacked up to its original place and the void drypacked or filled with steel shims. Check out my post "deepest underpinning" there are some good pics of the process.

Denick is right thou, if this is old news or windows and doors aren't jamming up, there is probably no reason for this expense. However footings can settle many years later if they are build on certain types of clay or if there is a change in the depth of the water table.

wackman

I checked windows and doors and they were all working fine but she just had it remodeled last year and she said there were cracks that were filled.

The house literally is bent right at the spot of the crack. When I sighted along the side of the house down the siding line you can see where it's flexing.

The crack looks very sharp and new on the outside of the foundation but a lot less new inside in the basement.

I"ll go over and take some pictures.

747

I say support what ever is over the bad foundation and poor a new one then set it on the new foundation and attach it. Here is the way i would do it. Now first i'm not in the buisness. I would get some good size beams. Slide it under the structure spaceing them according to weight load. Then jack them up to support load. Then remove foundation poor new then lower back down and pull beams out. Similiar to moving a whole house but smaller in nature.