new patio concrete too high

[Christo]

I've just returned from 3 weeks away to find that the contractor who poured our new back patio concrete has set it too high! At best it's level with the house floor and we originally had in mind to tile the patio. Water isn't a problem as we will be roofing the whole patio (11m x 6m) and he has put good fall on it anyhow.
Any suggestions for grinding 5mm off the concrete or similar? (Please, no jackhammer jokes...I'm still in a fragile state after discovering this little problem this morning!)
Thanks
Chris

[Terrian]

I've just returned from 3 weeks away to find that the contractor who poured our new back patio concrete has set it too high! At best it's level with the house floor and we originally had in mind to tile the patio. Water isn't a problem as we will be roofing the whole patio (11m x 6m) and he has put good fall on it anyhow.
Any suggestions for grinding 5mm off the concrete or similar? (Please, no jackhammer jokes...I'm still in a fragile state after discovering this little problem this morning!)
Thanks
Chris

Could hire a grinder from Kennards, about $100 mark depending on which state you are in.

http://www.kennards.com.au/

[silentC]

I'd be wary of grinding down a slab in case your steel is higher than you think. It should be deeper than 5mm but you are reducing the cover.

Anyway, if you are planning to tile, taking 5mm off still means you'll be at least 3 or 4mm higher than the slab is now by the time you finish.

What I would do is approach the contractor, pointing out that it's his stuff up, and let him know that you'll accept having him stencil it for the cost of materials. It will be as good, if not better than tiles, only a couple of mm higher than it is now, and cheaper.

[sports fan]

dont know what sort of arrangment you had with the concretor (contract?) but if you dont give them an reduced level (RL) or finished floor level (FFL) what can they be expected to work to?

i would be chipping off the concrete where ever needed to get the right height, if you expose any steel just treat it. it will be covered by the tile bed and tiles which will be under cover anyway... grinding will take ages and make mega dust for you

[dazzler]

What I would do is approach the contractor, pointing out that it's his stuff up, and let him know that you'll accept having him stencil it for the cost of materials. It will be as good, if not better than tiles, only a couple of mm higher than it is now, and cheaper.

Top idea re the stencilling, though to expect him to pay would be based on the fact that he was told the finished height initially.

[silentC]

i would be chipping off the concrete where ever needed to get the right height, if you expose any steel just treat it. it will be covered by the tile bed and tiles which will be under cover anyway...

Would you seriously consider doing that? Bashing off the top layer of a slab and exposing the steel and then, what, just whacking on some cold gal or something? And laying tiles over it? Would you really do that?

Yeah, re the payment, if it's your fault and you didn't tell them you didn't want the patio higher than your floor inside, you'd have to suck it up. You can't expect tradesmen to use common sense.

[Chumley]

We've got cycle paths and foot paths made out of concrete slabs that lift and buckle - the council workers come by now and then and grind the bits that stick up - looks like some kind of giant angle-grinder track. If your steel is low enough it might be a good way to lower the level, but it's a bit like breaking eggs to see how they work...
Cheers,
Adam

[sports fan]

Would you seriously consider doing that? Bashing off the top layer of a slab and exposing the steel and then, what, just whacking on some cold gal or something? And laying tiles over it? Would you really do that?

the steel should have 30 - 40mm cover of concrete over it so i would doubt he would even expose any steel, it sounds like not that much has to come out... as for laying the tile bed over it the rougher the concrete the better bond the bed will have to it

[silentC]

Well yeah but tile grout is not a real good seal and if any water can get to the reo it will rust and pop the slab. You're also reducing the cover over the steel, which is usually specified as minimum. 30 or 40mm might be 25mm in reality, or even less, depending on how fussy the guy was about getting the chairs level. I'd be thinking carefully before I started hacking away at it. Just seems like not that great a solution to me.

Anyway, I still think the easiest and cheapest solution is to stencil it.

[Ashwood]

Would you consider having a polished concrete finish? I recall seeing some threads on polishing n applying a finish to the concrete and have that as your final floor finish.

[Ronaldo451]

You're not seriously considering grinding down 5mm over 66 sq mtrs of concrete.....seems like a lot of time, effort, expense and dusty inconvenience. The suggestion about stencilling is a great idea, polishing the concrete presumably would not require a 5mm depth but is a job for the pro's and could get xxxx'y.

If the levels are comparable could you extend the same tiles into the room ajoining the entry to the patio area - ie make the indoor/outdoor continuing level a feature? If not, how about just to the inside edge of the entryway reveal with a bit of quad or similar to soften the rise.

I'd really be considering every alternative before hacking into the slab - good luck.

[dazzler]

You can't expect tradesmen to use common sense.

Then the complaint might be;

My concreter poured the slab 10mm too low and now I trip on it

[Terrian]

I'd be wary of grinding down a slab in case your steel is higher than you think. It should be deeper than 5mm but you are reducing the cover.

errr, if the steel is that close to the surface I would be very concerned what other stuff ups had been done !!!

[silentC]

I'm not concerned about exposing the mesh, it's just reducing the cover, that's all. If it's already a bit high in places or where mesh has been lapped, or if he's used the top slot on a 65mm bar chair you might be starting to get a bit skinny. I guess we have minimum cover - 25mm I think - for a reason, right?

[Ashwood]

How'z bout raising the rest of the house?

er... sorry, bad joke