cutting into a concrete block wall

Cut from each side using angle grinder.

Bash it out from the middle, tidy up the rough bits

OR

Hire a massive angle grinder

Rick

How about drilling a few holes through (with an SDS drill) to define where the cutout will be - and then cut half-way through from each side with your large angle-grinder?

hire one of those diamond chain saws, like Tommy Walsh uses

mrcheerful

Hire a Stihl saw with a 14" blade.

Just had another thought, you can hire a chain saw with a diamond blade, designed to cut concrete.

Rick

Drill through in several places with an SDS drill being careful to keep the bit 'square'. Cut through from both sides. Make the opening slightly oversize then shutter up and make good with a mortar skim to the dimensions required. For best results include a rebate in the shuttering to give a neat fillet round the opening.

Thanks guys

I think I'll try to save some hiring money and grind through from both sides. Making it oversize makes sense too.

Thanks again

David

Oh what fun you are missing, a dimond chain saw, the dreams of many a "DOOM" player are there ready to be acted out with that sort of a tool.

The angle grinder is alsmot certanly less lilkey to do you serious injury, but its still far from being "safe" in the way Americaians use the word.

Rick