Cutting fibre cement board

@Prof, if you're to be cutting circular holes, then a carbide/diamond tipped jigsaw or reciprocating saw would seem ideal, but there's a problem. The dust is nasty stuff, check out post #8 by Peter Kelly:

http://www.sawmillcreek.org/showthread.php?199310-Blades-for-cutting-Hardie-(fiber-cement)

You could try to vacuum the dust while cutting, but you'd need a vacuum with a HEPA filter (expensive), & that's able to contain the dust completely for disposal, or you're back to square one. Even then, you'd still have to remove the contamination from the nozzle, hose, & filter compartment.

Wet cutting would be ideal to contain the dust, but instead of using a Wet/Dry Vac (more problems than it's worth), let the residue run into a disposable bag/container that can be sealed & disposed of safely.

Sorry if I sound like a drama queen, but it's you, & your family's health that could be at risk.

My suggestion would be to wet, then scribe & snap your eave panels to length, leaving a gap between them, that you can fit with a panel that's safer, & easily cut to install your fittings.

Brad

https://www.workshop.bunnings.com.au/discussion/comment/113401#Comment_113401

Tile holesaw would have a diamond edge.

https://www.bunnings.com.au/p-n-6-piece-ceramic-tile-holesaw-set_p6370115

57mm is the largest size in that kit. You can get larger sizes in tungston teeth at bunnies.

I might end up in the naughty corner but you can look here too.

http://www.gasweld.com.au/catalogsearch/result/index/?cat=0&dir=asc&order=relevance&q=Diamond+Coated+Hole+Saw+

Prof

https://www.workshop.bunnings.com.au/discussion/comment/124283#Comment_124283

Thanks guys for all your help and suggestions..

I must say I'm very surprised at how dangerous this stuff is!! I always thought that fibre cement was a safe alternative to asbestos! It sounds like it's just as bad!!

Getting back to the job at hand...I'm planning on cutting out a circular hole approx. 30mm. in diam. to run speaker wires and HDMI cable into the next room.. and a large rectangular cut out out for an aircon..both in existing interior walls..

fredgregg &Brad..A diamond tipped hole saw sounds like the best way to cut the 30mm. hole..
I looked at Bunnings and Gasweld sites and they have wet cut saws, which would work fine if the sheet was lying down..but what about a vertical wall panel..Wouldn't any moisture applied get down into the panel and possibly cause some swelling?

Andy_Mann.. I think your idea of using a reciprocating saw with a diamond blade might be the way to go for the aircon cut out..This cut out will be on an exterior wall which also has fibre cement brick wall cladding on the outside..

Brad

https://www.workshop.bunnings.com.au/discussion/comment/131566#Comment_131566

I would wet cut any holes before you do your final fixing while the sheet is down.

For the aircon I would be tempted to use fill pieces rather than cut a hole, few extra joins but you can avoid dust by snap cutting the sheet.

Fibre cement is safer in that you can snap cut it where any damage to asbestos releases fibres.

Andy_Mann

https://www.workshop.bunnings.com.au/discussion/comment/131566#Comment_131566

@Prof for drilling the 30mm hole on an installed vertical panel, either a carbide tipped, or diamond coated hole saw would be fine, but I wouldn't recommend doing it dry.

For a cheap hack, set up your hole saw as normal, but before you fit it to your drill, scrounge a cheap stubby holder, make a small cross cut in the centre of its base & slide it onto hole saw shaft. Grab a spray bottle of water & dampen the inside of the stubby holder, & also where you're about to drill (it doesn't have to be saturated, just moist).

Partially drill, & hold a damp cloth under the stubby holder to collect any dribbles, as you'll need to repeatedly remove the hole saw to remoisten the hole site.

Repeat the process until you're done.

Then rinse the hole saw thoroughly under a tap, & thoroughly rinse the basin/trough. The hole saw's safely ready for another day. 🙂

Rather than rinse the rag, put it in a pastic bag, tie the bag securely, & drop it into your rubbish bin.

I'll get back to you on the cut out for your air-con later. 😉

Prof

https://www.workshop.bunnings.com.au/discussion/comment/136004#Comment_136004

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

Prof

https://www.workshop.bunnings.com.au/discussion/comment/136005#Comment_136005

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

https://www.workshop.bunnings.com.au/discussion/comment/139049#Comment_139049

@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

https://www.workshop.bunnings.com.au/discussion/comment/141092#Comment_141092

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

https://www.workshop.bunnings.com.au/discussion/comment/142628#Comment_142628

@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

https://www.workshop.bunnings.com.au/discussion/comment/143715#Comment_143715

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

Prof

https://www.workshop.bunnings.com.au/discussion/comment/144534#Comment_144534

Prof

https://www.workshop.bunnings.com.au/discussion/comment/145138#Comment_145138

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

Andy_Mann

https://www.workshop.bunnings.com.au/discussion/comment/145607#Comment_145607

@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

https://www.workshop.bunnings.com.au/discussion/comment/145971#Comment_145971

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

Jason

Prof

https://www.workshop.bunnings.com.au/discussion/comment/145971#Comment_145971

That's some clever thinking Andy_Mann..I think that could work quite well..

I think that jigsaw blade should do the job very nicely ..

Thanks again for your help..

Rhys

if the hole you have to cut is between 40mm and 300mm, then your best bet is an Xtorque XTO300 https://sydneytools.com.au/xtorque-xto300-40-300mm-adjustable-hole-cutter-kit

Prof

https://www.workshop.bunnings.com.au/discussion/comment/4003#Comment_4003

That's a neat idea with the cowling over the cutter blades..

In the end a builder did the cut outs for me..
He just used a tungsten tipped hole saw for the small hole and a reciprocating saw for the air-con cut out..

Rhys

https://www.workshop.bunnings.com.au/discussion/comment/64181#Comment_64181

i just realised it would have been too big, as the smallest it can do is 40mm

https://www.workshop.bunnings.com.au/discussion/comment/94673#Comment_94673

Hello guys,
I got a question here similar to the original topic.

What's the best tool to make a partially through hole on cement board? I'm aware by using a hole saw you will only achieve a completely through hole.

Basically I want to get the industrial concrete look by having those holes on the cement board.

Your reply is much appreciated

Brad

https://www.workshop.bunnings.com.au/discussion/comment/113848#Comment_113848

Gyprock Perforated plasterboard pattern.jpg

That the look you are going for?

Upcut spiral router bit for 12.7mm and under will leave a clean bottom.

Forstner bit for larger holes, not the saw tooth ones as they are more like a holesaw, will leave a vee point in the bottom of the hole.

Problem will be dust, I would stick to minimum holes and cutting.

Jason

https://www.workshop.bunnings.com.au/discussion/comment/113848#Comment_113848

Hi @MO,

Welcome to Workshop and thanks for joining in the discussion. It's great to see you've already received a helpful reply from @Brad. I trust our knowledgeable and creative community members will be able to provide plenty of assistance and inspiration for all your projects. Feel free to post whenever you need a hand or have something new to share.

Jason

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