Best Way to cut out a section of concrete slab ?

[colin H]

Hi Folks ,

I need to cut out a section of my concrete garage floor , to house a filter for my pond .

The hole will need to be around 2ft square x 2ft deep . I think the concrete base is around a foot thick .

Whats the best method , and what tools do I need . I do have a 9" angle grinder and a decent sized masonary drill , which could put a 1" hole through the slab and also has a jackhammer type attachment , which Ive used for breaking up small areas of concrete .

Would I be able to manage with these tools , or would I be better off hiring something ?

 

[Norcon]

Doubtful if its a foot thick. Unless you hit the foundation.

A hilti TE 3000-AVR will make mince meat of it, even if reinforced.

 

[catlad]

Mark your square out and then cut it with the grinder, then I would cut it into quarters and use the drill to break it up.

 

[colin H]

Mark your square out and then cut it with the grinder, then I would cut it into quarters and use the drill to break it up.

Thanks - I`ll give it a try !

 

[foxhole]

Drill down in all corners first and will indicate the depth of the concrete.

 

[r896neo]

i would be more concerned about sending cracks throught the rest of the slab if you just blatter away. A 9'' grinder is only going to give you a 70mm deep cut at best and the slab is probably between 100-150mm

You should either borrow or hire a stihl saw which will allow a 100mm-140mm cut depeding on model.

Or the slower but probably cheaper option would be to stich drill the exterior every 3'' to encourage it to crack there then tidy up the edges afterwards with the grinder