squaring up a slab?????

[Inspector807]

A slab was poured and was a good bit out of square, at one point it went from 6"s to about 10"s the concrete ment dug down beside the monolithic slab 12" deep and as wide as they needed to resquare the slab, the new concrete was not tied to the existing slab, my question is was it supposed to be or will it hold up being done like this, the ext wall was of 2x4 construction and load bearing, what is the appropriate fix for monolithic slabs that are poured so out of square, thank you

 

[austim]

Inspector 807,

I hope that I am correct in interpreting your post (please excuse me wanting to make sure that I have the facts).

You are concerned about a slab on ground, that is required to act as a foundation for a load bearing wall. When your slab was poured, it was not constructed to the correct dimensions. In an attempt to correct the error, the contractor has added a narrow strip of concrete beside the slab. This added strip has no structural connection to the main slab, but is the portion on which the load bearing wall will be supported.

If all this is close to your problem, then I would suggest that there is only one acceptable solution.

1. Remove the added strip of concrete entirely - it is of no structural value at all. If this involves a strong argument with the contractor, so be it. Do not under any circumstances accept any other 'dodgy' (or inferior) proposal for repair. If anyone was prepared to do what you described, they should not be trusted to provide quality work anyway.

2. Remove the concrete from the edge of the main slab, sufficiently far to expose the reinforcement and have a proper lap joint (whatever your local building code requires).

3. Extend the main slab reinforcement (with lapped bars and more longitudinal bars) to provide reinforcement for the full width of slab as detailed on your drawings.

4. Re-concrete the slab edge to the proper width.

Depending on the type of reinforcement used, you may be able to reduce the remedial work by using welding to extend the reinforcement, and thus cut back less concrete. However, I would not be too ready to accept welding, given the contractor's behaviour so far.

I hope that this may help.

 

[Inspector807]

Thanks Austin you were correct in your interpretation of my post. There were several areas that were corrected in this manor a couple were only in strips of 15' long -2"s wide at one ended up 4"s and 12"s deep, 4"s in the same lenght to 6"s to the worst 6"s on one end to 10"s at the other on a wall a min of 35' and load bearing- my thought was that it would shear off from the existing slab since the addition was not tied to the origional slab but was over ruled by the Building Official who said it was fine that there wouldn't be a problem and they were allowed to start building the next day, what would be your response to him?

 

[austim]

Inspector807,

I am not quite clear what your exact responsibility for all this may be.

If the Building Official has the authority to over-rule your opinion (and I totally agree with your view about the added portions of concrete shearing away from the remainder), then I suspect that you can do no more than put your objections in writing, and keep your copy until problems do arise.

Make sure that the Building Official cannot argue at some future time that you did not inform him. Hand your written objection to him/her personally (and give a copy to the builder as well), and record the date on which you do so.

What does the building's designer say about this? Surely the Building Official cannot also over-rule the structural requirements of the original design?

 

Is a monolithic slab as strong as the conventional block and slab where the 4" slab is poured on top.