Shaving Concrete

[htiek126]

A little off topic, but my neighbor had a contractor extend the exterior walls of the house for three rooms. The bonehead poured the concrete as much as 1.5" higher than the existing concrete slab, and then quit the job. The addition is now under roof and they are planning to install hardwood. Does anyone have an idea of how to efficiently reduce the height of the concrete? It mostly needs to be knocked down in the middle of the rooms. The new exterior walls are sitting on the slab and the slab is the right height under those walls.

 

[Junkman]

It can be ground down, but it is a messy, noise, and dirty job. Look for someone that does terrazzo tile work. They have the equipment, but they are also expensive. It might be cheaper to cut out the areas that are too high and have them re-poured. A difficult job no matter how they attack it...

 

[beenthere]

"The new exterior walls are setting on the concrete slab"

And some people wonder why we have building inspectors controlling our lives!!! Things like this make them necessary, sorry to say.

That wouldn't be an acceptable building practice around where I am. My guess is he is up the perverbial crick without a paddle. If the walls were on conventional foundations, then the high floor could be busted out, and a new floor poured. Don't see any easier way to do it.

 

[rambler]

That does sound like an unusual building procedure. Not sure it was right in the first place, that you can fix it.

--->Paul

 

[slowzuki]

Swami Ken sees a big concrete saw cutting out the centre area, jack hammer breaking it up and wheel barrow loads of cement being poured. /forums/images/graemlins/cool.gif

 

[BXMMCC]

I guess that I didn't understand the problem completely - or - why can't you raise the low points to meet the high point?

 

[Junkman]

The only reason that I can see that they couldn't raise the low points to be level with the high points is the ceiling hight and the fact that it is wood framed and they would have to protect the wood where it meets the concrete. Personally, I would put a pressure treated 2 x 4 around the walls and pour a top coat to level it using high strength fiber glass reinforced light weigh concrete and live with a lower ceiling hight. There are other remedies, but this is one of those cases that it would be helpful to visit the site to determine all the possibilities. It will take some creative imagination to resolve this, but it can be done. It will also cost some $$$$$ to do it correctly..

 

[htiek126]

The low points can be raised, however, that is almost the entire downstairs. The high points are limited to two 6 foot wide slabs with most of the really high stuff near the interface of the old and new slab. Tearing the entire slab and rebar up is certainly a solution, however, I was tyring to determine a better solution. Perhaps there is a happy medium in tearing out the highest spots and raising the surrounding areas to taper into the slightly high spots. Perhaps a concrete saw on a level guide could be used to saw level lines every inch or so. And use a jack hammer sideways to chip out the sections...

 

[jol1269]

first id be worried about the foundation as well as the correct thickness and depth of the footings if the contractor didnt know enough of how concrete work is done he may have done these wrong as well causing a bigger problem i suggest you tell your friend to get a structual engineer out to the site to evaluate it and he will more than likely have a resolution to the issue if he sees that the foundation and or footings are correct
/forums/images/graemlins/wink.gif

 

[Egon]

Having made many mistakes in the past rectifying errors is not new to me.

On the original approach one will try to fix the error by using alternate methods that will appear to be the quickest and cheapest. This may work but usually takes a lot of time a leaves a less than desirable result.

On the second approach the first repair job is touched up.

Finally; common sense kicks in and the offending areas are removed and rebuilt from scratch. On the final analisis this will usually be the cheapest and fastest approach.

Egon