Using a 2-stroke saw in a cellar

[chrisbyrd]

How old is the house in question? Also how damp is the cellar area?

The house is about 150 years old I think - cellar has a couple of inches of water in it at one end for probably half the year

 

[SimonH2]

If using a petrol drivel cutter, you can use water to eliminate the dust. Combine good extraction (you can hire extractor fans and ducting) with an air fed mask (commonly used for spray painting, not just the Fire Service) to provide uncontaminated air from outside, and you should be fine.

Given the choice, I'd pick wet cutting any day. As said, the room will disappear in seconds with a dry cut, while a wet cut just leaves a stream of "milky water" to clean up afterwards.
But don't even think of using a petrol driven machine without both good extraction and an air fed mask.

 

[JohnD]

If the house is 150 years old, the floor might not be modern concrete. Give it a bang with a bolster and club hammer at the edge to see how hard and strong it is. Once you have made an opening, it is much easier to enlarge it.

Have you considered the biggest, heaviest SDS+ drill you can borrow or hire, on rotostop, with a chisel steel? and ear defenders, of course.

 

[chrisbyrd]

Happy to report that a 9" 110v grinder is doing quite a nice job of this and keeping it a bit damp is going wonders for the dust (bring careful with the electric!)