Cutting Concrete - HF Angle Grinder?

[Mordi]

Sometime in the future, I would like to build a built in stone BBQ island in my backyard. The area I have in mind is a stamped concrete pad located under open air patio, adjacent to the house. The concrete on the patio is approx. 4 inches thick and reinforced with rebar.

1) Can I use the existing stamped concrete pad as footing or the new BBQ build or do I need to cut and remove the exisiting concrete and build a new footing?

2) If I need to build a new footing, what tool should I use to cut the concrete? I see that HF has a 4.5" heavy duty angle grinder for $20 - will that, along with a diamond blade be suitable for the task? If not, is there another tool or brand of tool I should consider?

Thanks,
Mordi

 

[4x4mike]

I'm not sure about question 1. In regards to question 2. Nothing at HF is heavy duty, let alone their angle grinders. You can cut concrete with a concrete cutting wheel and that grinder but it'll take awhile, it might kill the grinder and if it doesn't it won't last much longer than your project.

You might be better off drilling some holes in the concrete and mounting some pieces to anchor a footing or something else you can built on to/off of.

 

[jniolon]

Mordi

you didn't say how large a bbq you were building or how large the patio is now... size does matter. For a small pit I think you'd be fine but for the mongo man kitchen... I'd pour another footer.

AFA the grinder... a 4.5" grinder wont give you that much depth...probably something around 1.75"... which would give you a clean edge on top where it's seen and you could bust the rest out with a sledge hammer. Make a couple of cross cuts or diagonals to make it break up in managable pieces.

My suggestion would be to rent a concrete saw or demilition saw with a concrete blade. Think of a big chain saw body with a 145" guarded blade instead of a chain... you can get a walk behind model (you don't have the weight to deal with... or hand held type like the chain saw I mentioned above.....most are water cooled to keep down most of the dust and cool the blade... ask the rental guy for usage instructions. With one of these saws it will go much faster, you'll be further away from the dust and not nearly as tired at completion... check with local rental stores but for a hundred bucks or so you'll be done in no time.... might even get 1/2 day rate...

BTW if that concrete has been there 10 or 20 years... it's gonna be hard. Concrete never cures... it just keeps getting harder as the years go by...

I'm sure you know safety glasses, ear protection and a good respirator are a must... not just a nuisance mask... that is if you want to breath as you age,

later
John

 

[alex71]

you can't cut something that's 4 inches with a 4.5 inch cutoff wheel, unless you can get to it on all sides.

 

[-B-]

Small cuts like for a BBQ use a circular saw with a dry blade it will be the cheapest and fastest method. ( less then an hour)

 

[Jim Stabe]

Small cuts like for a BBQ use a circular saw with a dry blade it will be the cheapest and fastest method. ( less then an hour)

What he said.

Jim

 

[Kev442]

Yep, circular saw you are not heavily attached too.

Actually, my $30. B&D has done this twice, plus cut metal (another no-no), and done everything else I've thrown at it over the last 24 years (alot!)
Who needs a worm drive?

 

[Mordi]

Some good ideas mentioned here.

I got enough info to do some damage

Thanks to everbody for their help

Mordi