Cutting fibre cement board

[Prof]

Hi guys,

What a great idea this forum is..

You don't always find what you're looking for in advice on the DIY section of Bunnings website..

My question is...What's the best type of power tool to use for cutting a large diameter hole in fibre cement board?

[Prof]

Brad...The sheeting is already up..This is an existing room...

[Prof]

Andy_Mann...Brilliant idea for the hole saw cut!

That would save a lot of messing around with vac. filters and the like..

Thanks for that...

[Andy_Mann]

@Prof, it's a pleasure mate, in fact I should be thanking you because if I hadn't looked up drilling in fibre cement, I wouldn't have known about the risks myself.

My upcoming project where I'm just to be making straight cuts, if it needed trimming, I have no doubt that I would've got out my trusty angle grinder fitted with a masonary wheel, & gone to town on it.

Now for the square/rectangular air con hole. Is the outside cladding a weatherboard style, or single sheets where you want to make the opening?

What size opening do you need to make?

Are there any elecrical cables in that area?

[Prof]

The outside cladding looks like brick but it's just a raised shape on what looks like fibre cement..

I've just recently bought this place and I've never seen this type of panelling before...

The cutout for the aircon. will be approx.450mm. x 320mm..

There aren't any cables in the way...

[Andy_Mann]

@Prof, I'm hoping that your home is post 2003, & the fake brick is from this Aussie manufacturer, check them out:

http://www.durabric.com.au/

If that doesn't look to be it, then I ask, do you know how old the house is?

Or, could you send a photo of the faux brick cladding?

[Prof]

No it doesn't look like that one..I'll take a photo and post it here..

[Prof]

[Prof]

The whole panel is approx.10mm thick and it has Hardie on the back...

[Andy_Mann]

@Prof, someone mentioned tungsten tipped hole saw blades for drilling, so maybe we'll go with this jigsaw blade:

Tungsten tipped & coated blade

Erring on the side of caution, grab some scrap wood or ply to make a suitably sized temporary plate for your jigsaw. Drill a hole in it, roughly where the jigsaw blade will fit through, then glue a cheap & thickish household sponge to it, with plenty of sponge overhang at the front or rear.

Then attach your sponge plate to the base of your jigsaw with double sided tape. Next up, poke a hole through the sponge, & fit the blade.

I'm thinking that again, wet cuts are the way to go, using the same technique as for the hole sawing. You may not need the moist rag to collect the moist contaminants, the leading or trailing edge of the sponge should take care of that.

As before, wash the blade if you intend to keep it, then securely bag & dispose of the temporary sponge plate that you made, & the piece that you cut out.

For an added precaution, maybe seal the edges of the cuts that you made using a cheap throwaway brush & the dregs of a used paint tin.

[Jason]

Lots of great advice being shared in this discussion. Great work @Andy_Mann and @Brad.

Jason