How to cut limestone?

[NJ]

Hi, my backyard is mostly poured limestone. I would like to cut 1sqm square hole into the limestone near my fence to grow a climber along the fence. What is the best way to cut into the limestone without causing cracks in the remaining area please. 

[JacobZ]

Hi @NJ,

Welcome to the Bunnings Workshop community, it's great to see you're getting stuck into some home improvement.

The most effective way to cut large amounts of stone is to use a concrete saw, such as this Demolition Saw that can be rented through most Bunnings stores (ensure you check availability with your local store).

If using a concrete saw, please make sure to wear all the necessary personal protective equipment such as gloves, eye protection, long pants and work boots and most importantly a respirator to protect against any airborne silica dust.

Please note that these tools are heavy duty bits of kit, that if used incorrectly, can cause harm. If you haven't used a similar tool before, it is worth contacting a professional to carry out this job.

Don't hesitate to get in touch if you have any questions,

Jacob

[NJ]

Hi Jacob,thanks for your response. it is not a large area that I wish to cut. Only about a square metre to plant a climber. Are there hand tools I could use? Can I use a hammer and chisel?

[JacobZ]

Hi @NJ,

You could in theory use a hammer and chisel, but it would take a long time, a lot of effort and each strike with the chisel could potentially create cracks where you don't want them. 

I just want to confirm that you meant 1 square metre, not 1 square foot. From experience, 1 square metre of concrete or limestone may not seem like much, but it is a lot more tedious to get through than you may think.    

Are you also able to measure how thick the limestone is? This is definitely something to consider when working out the best method of going about your project.

Jacob

[NJ]

Hi Jacob, thank you so much for responding. 
the thickness is about 55mm or 2and 1/4 inches. 
a square foot would be sufficient.

[JacobZ]

Hi @NJ,

If you have access to a drill, the best way outside of renting the before mentioned concrete saw would be to mark out the area, then using sufficiently long masonry bits, drill a number of holes around the internal perimeter, then "connect the dots" using a hammer and cold chisel.

This method will give the limestone guidance on where to break. If you were to just start chipping away with the hammer and chisel, like mentioned earlier, I'd be concerned that it would crack in ways that aren't intended.
 

What do you think?

Jacob

[NJ]

Sounds like a great idea Jacob. I will give it a shot in a small inconspicuous area. Thanks so much for your help.

[Noyade]

Late thought @NJ

Making multiple passes with a 9" angle-grinder (they're very affordable these days) armed with a stone cutting disc to the depth you require - would limestone break nicely at the bottom if a cold chisel was wedged between the cuts?

Just a pre Dan Murphy thought. Cheers.

[JacobZ]

This is also good advice from @Noyade. 

If you choose to use this method, please remember to wear all relevant personal protective equipment, ie safety goggles, gloves, hearing protection, long sleeves and pants and most importantly a respirator as grinding cement products will create airborne silica that is extremely detrimental to your health.

Keep us in the loop,

Jacob 

[NJ]

That’s great Jacob. Enjoy your Dan Murphy expedition!