Removing bonded topping

[asixth]

Hi guys

I am doing a refurb of a shopping mall where the existing mall being widened. The existing mall has a tiled finish. Widening the mall requires us to remove 2" (50mm) of an existing bonded topping so we can provide new tiling at the existing level.

My Question:

Can I remove the bonded topping easily, possibly by jackhammer, or should I just demolish the existing slab on ground and pour a new slab at the required level?

All comments will be appreciated.

 

[JedClampett]

You'll have a lot less hassle with the contractor if you remove the whole slab and replace it. It's likely to cost about the same, as the demolition will be easier (although there will be more debris to haul away).

 

[BAretired]

You could specify:

At the option of the Contractor, remove the existing slab and replace with new slab as shown on the drawings OR remove the tile and topping and replace with finishes as shown.

Why not give the contractor his choice? He is in a better position to determine which is cheaper.

BA

 

[asixth]

Thanks guys

 

[jgailla]

asixth,
From a construction standpoint, you could have problems if you leave the choice to the contractor.
The act of dislodging the bonded topping, especially with jackhammers, could damage the underlying slab.
If there is nothing in the specs about this, the contractor could claim that he did it per the design and that he isn't responsible for the damage.
It may be paranoid, but I've been in a lot of stupid arguments with contractors.
Just a caution.

 

[JedClampett]

As I posted above, you'll be a lot happier if you take the decision out of the contractors hands and just remove and replace the whole thing.
If you give him an option, you have to provide details for both cases, not to mention he might choose to remove the topping in some areas and the whole slab in others.

 

[bridgebuster]

How big of an area are we talking about? Hydrodemolition might work. You need a large area for it to be economical.

There are also scarifiers that will remove tile.

 

[asixth]

We are not talking a large area, approximatley 3m x 20m (10' x 65'). Just to make things more interesting, it has just been discovered that the topping slab isn't a topping slab but the slab on grade has been stepped-up 2" (50mm).

Now my question is:

The contractor wants to remove 2" (50mm) of the slab, it is a 5" (125mm) thick slab on ground. Removing this thickness of the slab will surely remove the wire mesh reinforcement. Is this unacceptable to remove the reinforcement and have the slab on ground unreinforced with a tile floor finish?

 

[hokie66]

I think what he is proposing is unacceptable. I don't know if it would remove the wire or not, as that is often found on the bottom, but if you should have a 125 slab, 75 is not good enough. I think any effort to remove 50 mm would inevitably damage what is left. Taking it out and recasting at the correct level for the new floor finish is the way to go.

 

[BAretired]

I agree with Hokie. Remove the whole slab.

BA