How do I determine if cracks in a new concrete pad are structural? What is contractor's responsibility?

Question

No other cracks on property. Cracks in the area graded & built up, not tampted of a 40'x40'x4" concrete slab floor of a metal building. Hairline cracks started in 3 months & are expanding. Have contacted the builder but they avoid me. The NE corner seems to be settling & cracking. If you place a long level on a crack you can see the concrete is dropping. How serious is this?

The sub-contractor that did the clearing & grading missed the location by 2'. The concrete sub-contractors had to move the forms by hand digging them. The footings are 2' bigger. That is alot of concrete to shift. I have lost confidence in the grading contractor.

I believe that the northeast corner was not graded correctly and that corner is settling & cracking.

How far will it drop? How do I determine the extent of the damage? How do I have the problem corrected? Does it need to be redone or is it just cosmetic & a floor sealer would repair it? How do I negotiate with the contractor?

Are there control joints in the concrete?

Yes. The joints run down the middle north to south and east to west cutting it iinto quarters.

And it was ok'ed by the city inspector on 12/28/05

Building Approvals
200 Set backs
204 Footings, forms and steel
208 Slab grade

However there is a section on the permit form concerning Grading and site work that was not checked.

Grading/sitework
100 Rough grading/building pad
104 Storm drain structures
108 Precise grade
199 FINAL GRADING

I assume that it was not needed as alot of lines were not written off.

Answer 1

If I were you, I'd start gathering evidence now so in the case that this becomes a major problem, you have some proof. Save all communications to the contractor. This may be their fault, and if it is, it may be their responsibility to fix it. take pictures. Copy all written documents. Tape record all phone conversations if possible. Save all emails. You may need to prove that you contacted them, and that you noticed the problem long ago if this ever becomes a problem.

Whether it is serious or not depends on where it is and what kind of building it is. On a sidewalk, probably not. In a parking garage, yes. Still, if their policy or warranty covers it, they will have to fix it regardless of how serious the issue is.

Hope I helped.

Answer 2

Are there control joints in the concrete? This slab is too large for there not to be. It would definitely crack without any joints.

It sounds like the subgrade wasn't compacted enough and there is settling, which in turn, is causing the concrete to settle and crack. I agree with one of the previous answers - document the heck out of this concrete. Take as many photos as you can and keep all the written/phone conversations. If it was constructed incorrectly, it is the contractors responsibility to fix it. It might be a good idea to speak with a lawyer and have them review your contract with the contractor.

Answer 3

First contact a PE and get a report explaining the damage in the structure and determine the responsible of those damages, if the contractor was negligent in his work you can fill a claim in the the state board (what state are you?) and this board can begin an investigation besides that with the report you can begin a Civil Process against the contractor, contact the general liability underwriter of the contractor and explain them your situation they had to be responsible for your damages if the contractor do not want to do it, if the contractor subcontract any other parts the contractor is the responsible with you. Anyway is better if you contact a lawyer that can handle this better

Answer 4

If you got pre-pour and post-pour inspections--as is required by most state's building permits---and the okay was given by the inspector to go ahead with the build, then the contractor is pretty much done. If this building is just to be a workshop and not a "living space", then you may be able to talk with the contractor to patch the cracks.

However, inspections from the county's building inspector were required, I'm sure. If the inspector who inspected the gradation, the footings, and pre-pour, and after the concrete was poured and dried and he signed off that everything was okay, you may not have much of a choice. You may have to contact them to do a re-inspection.

That's a huge building to be putting on a solid concrete slab.

Answer 5

Your driveway is probable cracking because of the fact the floor decrease than it settled. It merely happens. in case you seem at an old sidewalk you will see that the guy sections are actually not any greater completely point with one yet another. that's why sidewalks are poured in sections--to cut back cracking which will happen with the freeze thaw cycle. The pad you place your warm bath on interior of reason small and probable has room to strengthen and settlement slightly. A driveway interior of reason long and extensive and there is greater floor decrease than it to settle. I stay in an area the place we've an excellent kind of heat interior the summertime and it gets chilly interior the wintry climate. each concrete driveway i've got seen has had cracks from that and the shale that underlies it shifting. that's why while we lived interior the country we had a packed and rolled gravel driveway. it would supply and take with the soil shifts and can desire to be fastened each few years by ability of slightly greater gravel and rolling it back.

Answer 6

The seriousness of the situation may depend on whether the concrete floor included rebar (reinforcing steel bar) and the loads it must carry (vehicles?). I'd suggest that you consult with a Professional Engineer (PE) specializing in structures (civil engineer?) for an evaluation. Only PE's can testify in court as experts if that is required. Perhaps the PE's report would help convince the contractor (or designer?) to resolve the problem (out of court) if they are clearly liable. Good luck.

Answer 7

it sounds like poor compaction of the underlayment. 4" also sounds a little thin for that large a slab. i would get in a consulting engineer and maybe a good lawyer