Any concrete people here?

[Tramp429]

http://www.concretenetwork.com/concr...ete_cracks.htm



I've seen concrete poured in Florida with no rebar many times. However, they used steel mesh.

[Beemer]

I think the backfill was done about a day after the walls were poured

Concrete wasn't cured in the least and yet they backfilled. This is stupidity at work.

If possible, run a string-line along the top of the foundation wall that is cracked, just below the rim joist, from corner to corner to see if the wall is wowed inwards towards the house.

If it is wowed, you found the cause of the crack. Back filling against an unsupported, uncured foundation wall. This shouldn't be attempted before 7 days and even then, the sub floor must be installed before even a bob-cat comes anywhere close to the foundation.

The developer is at fault for putting the push on most probably. Of course, backfilling creates easy access to the building and thus speeds the building process up considerably. But at what cost if damage is done?

[BBA]

Originally Posted by TOAD6147

I would not accept ANY cracks unless an inspector or building official says it's acceptable safety-wise. Even with that, I would not accept it. BTW, I can't think of any jurisdiction in Florida that would allow a slab to be poured without re-bar. It's in the Florida Building Code, for God's sake.

You want to find the code...because my inspector said it they did a fine job...even with the cracks, which were explained away as normal.

[Chuckiechan]

I think you should talk to the county building inspector and ask for a re inspection. Or see if you can get a structural engineer to take a look.

Just who is this "inspector", and who does he work for?

Do you have any photo's?

And Beemer is right on with the plane of the wall. If it's out of plane, that's slam dunk trouble.

[mad1]

Originally Posted by Chuckiechan

I think you should talk to the county building inspector and ask for a re inspection. Or see if you can get a structural engineer to take a look.

Just who is this "inspector", and who does he work for?

Do you have any photo's?

And Beemer is right on with the plane of the wall. If it's out of plane, that's slam dunk trouble.

I have pictures of the low spots but not the crack. I will get more pictures this morning and post them later.

I like the idea of running a string across the back wall to check for bowing,a basic idea but effective.

I will be contacting the inspectors office Monday afternoon to visit and go over the results.

I have even considered hiring a concrete company, not affiliated in the area, to do a inspection of the foundation. A friend of my father in law owns a large concrete company and said he would look at it if we did not get satisfactory results from the building company. This would give me two three opinions on the foundation.

Thanks for the input everyone!!!!!!

[clancy]

The string could give a false negative or a false positive since you are basing the test on the assumption that the wall was poured perfectly.

[electric]

one of the questions i would ask the builder is at what strength
the concrete was pour at , higher the strength more the cost to
the builder

what ever the out come i would have the dirt remove from the
damage area ,repair if possible and make water tight

[Beemer]

Corner forms are leveled up, braced and spreaders used to be near perfect as possible, as well as the wall is string-lined for straight and then braced before the pour commences. (The leveling strip isn’t a factor) There should be no problem with the string-line test since you are only repeating part of the process that straightened out the wall before the pour.

Observing the rim joist corners, if possible, over the concrete corners, should also tell if the concrete corners are good. The concrete is supposed to match the sub-floor dimensions +3/8”.

If the wow is let's say, 2”+ offset, you know the string is telling you something and that amount of offset would be enough to crack a foundation wall considering the wall was string lined in, in the first place from corner to corner.

The wall is probably water tight since the wall has been waterproofed with spray on or roll on tar before the backfill.

The problem lies with relying on wall anchors to support a weakened foundation wall. Further settling of the backfill will put a lot of stress on the anchors or the 2 x 6 nailing plate where the wall should be handling the lion’s share of the inward stress created by the backfill as it settles. A cured wall can handle the load easily.

Cut Lines:
If the basement is the same overall dimensions as the floor above, it make sense that the basement was dug out to the same depth as the footings. A soils engineer gives the go ahead for foundation work if the hard pan is showing or on rock or properly compacted pit-run. 4" perf perimeter pipe is installed along side the footing to catch any water that makes it to the bottom of the foundation wall, which in turn, directs the water away from the foundation to the storm pipe leading to the main storm service line under the road. This is a common situation encountered when prepping for a foundation.
The engineer will not sign off if you are attempting to put your footings on clay unless you install cardboard Boyd Forms under engineered floating footings bearing on peers, witch must make it down to the hard pan or rock. If the water table is high, there may be an extra requirement of Big-O to be installed inside the foundation wall footings with a sump pump or even 2.

The basement floor will be prepped with drain rock for argon trap and a top layer of leveling sand finished off with 6m poly, sealed. As a result, he basement has no water problems, is below the frost line, (if applicable) thus there is no possibility of anything heaving such as might happen with exterior applications of concrete. (Shouldn’t happen anyway if the exterior concrete is on properly prepped surface.)

Cut lines aren’t necessary for interior concrete applications and is a waste of time due to all the other building processes in place that will take care of any possibility of heaving.

Mesh or rebar is used in a basement slab for suspension in case any hollows form under the concrete slab due to minimal settling of the prepped surface underneath.

Have I missed something?

[RedFury]

think you pretty much covered it. I don't know a lick about concrete work, but what common sense I posses leads me to understand what you wrote Beemer. I've also seen plenty of stages of home construction, so I do have some sort of offhand experience/gathered knowledge, though I wasn't aware of some of the specifics you mentioned in regards to a clay base....don't run across that much up in my area as we are mostly sand.

I certainly would not be happy with a basement wall that wasn't looking up to snuff, and from what's been described thus far, it isn't.

[Beemer]

So far there is only a superficial crack. The rest is still to be determined. I've described a worse case scenario. Hopefully the crack isn't as bad as I've described so that Mad1 can get on with living in the home with a big smile on his face.