# Cracked sagging slab foundation?



## Project_Pat (Jul 13, 2008)

I need some advise, I am considering purchasing a contractor speck home that was framed only...Well it has been sitting there in this condition for over a year but this is Arizona so the framing appears to still be sound.

My real concern is the concrete slab foundation... it is cracked in multiple areas in the living portion of the home....I had a floor grinder look at it and he seems to think that just grinding the slab level and sealing the cracks with epoxy is all it will take to repair the unleveled floor.

My concerns are further settling once the floors are ground level and cracks in the tile floor that i had planned on installing.

I trust this fellow but i just thought it couldn't hurt ask for others opinions.

Here are some photos of the cracks.


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## 6stringmason (May 20, 2005)

It appears obvious that it wasnt graded right or compacted properly with correct drainage. I would be concerned about further cracking if it were me.

THat being said, it is Arizona and I guess where you are you dont have to worry about alot of rain or freeze/thaw with upheaval.

Still, its alot of major cracking. If there is rebar in though, wheres it going to go. 

Like they say, theres 2 for sures about concrete. Its heavy, and it cracks.


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## Darwin (Apr 7, 2009)

The long horizontal crack would give me reason to pause.....


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## thom (Nov 3, 2006)

long cracks are normal for slab-on-grade houses. There are no expansion joints. Over time the concrete shrinks and cracks. 

The pictures don't show differences in elevation but minor differences are not an issue. The slab is just that, a slab floor, not a foundation. Even cracked as it is it still offers significantly more loading capacity than a standard wood framed floor. 

The issues are finished flooring. If you tile you will need a crack isolation membrane. If you carpet or install a floating floor nothing should be needed.


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## tgeb (Feb 9, 2006)

Looks like shrinkage cracks to me.


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## RickS (Jun 9, 2009)

Not to change the subject, but if you do buy it, i'd get it tented for termites. It's been sitting open for quite some time.


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## thom (Nov 3, 2006)

forget the termites, AZ is dry. Unless there is moisture present termites are unlikely. The occasional rain they get is probably not enough.


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## RickS (Jun 9, 2009)

I was referring to drywood termites, those are the kind you tent for.:thumbsup:


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## SLSTech (Sep 13, 2008)

Get the ground checked - they probably didn't & it might have required a post tensioning system

Where is it at? (speaking of that - do us a favor & put your location in your profile)

No termites in AZ? Hah, I have a bridge to sell you - granted they are worse in other places, but trust me they can be an issue


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## Project_Pat (Jul 13, 2008)

Here are a few more photos of more cracks.
The "house" is a large ranch layout with a open air courtyard in the middle of it...These cracks are all around the center areas of the living portion of the home...The garage floor does not have cracks in it because there are expansion joints.

The "house" is in Litchfield Park and the subdivision appears to have been built on farm land, there are many cookie cutter homes identical to this one that are 100% built in the area.

There are no elevation changes on each side of these cracks, however the floor has areas that are 3/4" or more that are out of level.

Yes....Termites are a concern also.....they can creep up through foundation cracks to attack wood...I have not had the "home" fully inspected for termites however..I just had the floor looked at because this many cracks is obviously a big red flag.


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## thom (Nov 3, 2006)

Pat, I built in Albuquerque for 30 years. Those are the same cracks we see in virtually every house when the carpet is pulled up. They are standard shrinkage cracks. On occasion there is even a very slight change in elevation at the cracks but I'm not aware of any problems associated with them. 

It appears as though the sill plates used are treated lumber. That is a good thing and will work to prevent termite problems. 

The straightness of the cracks is interesting. These may be locations of cold joints from the pour but they don't appear to be an issue. 

The diagonal crack coming from the inside corner by the door is quite typical. There is an inside corner in the slab that is the starting point for the crack. It is not unusual for these cracks to develop even before the house is completed. 

I assume you have copies of the plans. Check to verify that if there are any interior bearing walls that they have been properly located on the slab. The slab will be thickened in those specific locations to support the additional loads.


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## tkle (Apr 15, 2006)

SLSTech said:


> Get the ground checked - they probably didn't & it might have required a post tensioning system
> 
> Where is it at? (speaking of that - do us a favor & put your location in your profile)
> 
> No termites in AZ? Hah, I have a bridge to sell you - granted they are worse in other places, but trust me they can be an issue


Arizona already bought the bridge. It's at Lake Havasu.


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## tkle (Apr 15, 2006)

Control joints can be cut in slabs. Concrete will crack anyway.
There seems to be an excessive amount and if you're having to grind them down. If you simply epoxy without doweling you could get another crack an inch away.
What I see is a red flag. If you have to ask...I'd look at the framing and everything closely. Was the guy cutting corners? Was it a mom and pop builder with no clue?
Make an offer contingent with sawcutting out a 18" section to check for steel and compaction.
Where's Ladmo?


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## SLSTech (Sep 13, 2008)

FYI - from LP Code site




> *With the native soils we have do I need a base course below my concrete floor slab?*
> 
> Yes. Section R506.2.2, I.R.C., requires a 4-inch-thick base course of clean graded sand, gravel and crushed stone.
> 
> ...




Ask for the soil report - as I recall they are one area were PTC was basically standard practice, along with AJ & CC area's --- almost everyone started going that route after DR Horton or Del Webb got nailed on all those failing foundations


*TKLE*, I know the London bridge is in Havasua - amazingly I never saw it when I lived out there


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## Project_Pat (Jul 13, 2008)

Heres a photo of the back patio that shows more detail of the footing.

I appreciate all the advise, things are slow here at the moment and i am considering purchasing this "house" finishing it off with the crews i work with who are also hurting for work, and moving in.


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## tkle (Apr 15, 2006)

Looks like the footing was placed and then backfilled and then the slab placed on top. It may be a compaction problem with the backfill. It may have been missed in inspection.


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## user50444 (Jul 25, 2009)

the only major thing I would have a concern about is what the foundation was filled with...? foundation walls w/ a slab at grade usually is excavated by stripping of top soil + left unexcavated where footing/walls are placed. then is best filled with a 3/4" stone. it is possible it was filled with sand or other material which includes excessive compacting + time, but cheaper for the material. cracks are cracks,... as long as seperation does not occur from settling not much that i'd worry about, minus some concerns on selecting your floor covering. I'm sure you can make a few calls to the people + companies involved in the excavation + flatwork portion of that project to find fill used, + reinforcing scheduling. control joints would have been great but, it could be that when it was built it was to be covered with carpet + so on. 
Between re-entery, settling, + shrinkage cracking - mixed with the foundation sitting on virgin ground + slab resting on that + placed ground. something for surely is going to give. do some research on those questions to confirm buy or stay waway from.


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## tkle (Apr 15, 2006)

I'm thinking the slab and the walls were placed within a short time frame.The walls were backfilled while still green so they were light on the compaction. It was just a small bit of fill and the inspector felt bad making them pay for another compaction test so he let it slide. Either that or it just cracked. It's probably cracked all it's going to. None the same you're taking that gamble and it should be reflected in the price.


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## B.K (Dec 15, 2008)

If that was my home, I would cut out a small portion of the floor and get a soil sample taken, see exactly what was done before the slab was poured. 

Could be a million different reasons for the cracking of the concrete. They may have started framing before the concrete was cured enough. Maybe the slab wasn't flooded when poured, no rebar was placed in the concrete. The concrete may have been to wet when it was placed, etc.

Open her up and see what exactly what the deal is.

-Bill


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## rbsremodeling (Nov 12, 2007)

Buy the damn house.


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