Way to remove some concrete (gently!) ?

[Frank Watson]

I need to re-tile a hearth in my 1899 house. The hearth is on the first floor. I lifted the old tiles, and underneath, I find quite hard concrete. I need to remove about 1/4" of that concrete in order to be able to lay the new tiles flush with the surface of the floorboards. What is the easiest way to do this without shaking the house to bits? The house was built in 1899 using lime mortar. U guess the padstone under the hearth is probably on the top of a brick corbel, since there is nothing visibly sopporting it in the room below. Therefore, I dare not start attacking it with a jack-hammer. Even belting it with a lump-hammer and chisel might cause the brick corbelling underneath to fall apart!

Thanks for any suggestions.

Frank

[raclyqm]

Drill some holes close together and then join up with hammer. Slow but painless.

[Frank Watson]

John, Thanks for the suggestion, but I'm intent on ending up with a dead level floor.. otherwise your idea would have been the answer.

Frank

[Frank Watson]

Thank you for this suggestion. It sounds like it might work!

Frank

[John Rumm]

Put spacers under all the floor boards then ;-)

[Alex]

If dust is not a problem cut with a disc cutter a crisscross pattern then chop out with bolster and hammer.

[Simon Avery]

Hello Frank

Diamond saw? Large angle grinder? Both messy.

[Michael McNeil]

Are you certain it isn't just resting on a trimmer? (A framed out double width of joist.) Chopping it out with a sharp chisel should not harm anything.

If you go too deep, just refill when bedding the new tile. Drill through for an idea of what's there.