Cutting fibreglass re-inforced cement board (?)

[YorkshireMidge]

I'm trying to cut out a much larger access hatch in box section in a bathroom hiding the various pipes, water meter etc. Rather than being plasterboard, this box section is made of material which is grey and fibreglass re-inforced. It's about 10mm thick and hard as nails. It's also quite brittle - such that I would imagine score and snap would work if you were just cutting a sheet of the stuff to length, rather than having to cut in situ.

My best guess with it being a bathroom is its some sort of cement board but, I have used cement tile backer board before and don't remember it being this difficult to cut.

A hacksaw blade will cut it but it's hard work - it cuts at roughly the rate of aluminium of the same thickness. The grit edged blade in my Bosch multitool also makes an impression, but is also very heavy going. Any other blade blunts quite quickly. I have about 4ft to cut in total, so wondering if anyone has any better ideas for next time I attack it?

My only remaining ideas are to buy a load of drills of the same size and chain drill it, or perhaps see if my jigsaw is any better.

Thanks!

 

[footprints]

You could try a BAHCO 14" Multi-Purpose/ Angle Hand Saw. A search on the web shows several suppliers.
Used to be very popular at one time I have cut slate with one, OK the blade will be shot by the time you have finished but you can replace it.

 

[HERTS P&D]

Are you sure it is not asbestos?

Andy

 

[freddiemercurystwin]

Hard as nails? Age of the property could discount asbestos ...... If it is then hand tools and mask is way to go really.

 

[^woody^]

A hardpoint wood saw

 

[YorkshireMidge]

I think the flats were built mid to late 1970s. I've been wearing a mask just in case and just doing some small test cuts - but the fibres are large and very visible like the reinforced matting on the back of an acrylic bath, hence my conclusion I'm dealing with fibreglass.

 

[YorkshireMidge]

You could try a BAHCO 14" Multi-Purpose/ Angle Hand Saw. A search on the web shows several suppliers.
Used to be very popular at one time I have cut slate with one, OK the blade will be shot by the time you have finished but you can replace it.

A hardpoint wood saw

Found a 14" Bahco hardpoint at Screwfix, so will probably give that a go. The box section is only about 6" deep so anything longer than that will be a problem. Thanks for the idea.

 

[chappers]

cheap jigsaw blades and a few of them, they will blunt quite quickly

 

[YorkshireMidge]

Well, I got the wretched stuff cut on Saturday. The solution I ended up with was a combination of chain-drilling and using the Bahco hard point toolbox saw a couple of you had suggested. I remembered I had a pack of cobalt tungsten carbide tipped drills (the ones I have look like masonry bits but according to the pack, they are multi purpose and cut steel too) which I got a while ago to drill some engineering bricks - and they went straight through the stuff on a conventional drill setting, far faster and quieter than a saw could have done. With some of the chain drilling cut through with the saw, it was possible to break it easily across other chain drilled sections. Bahco saw has had it, but it was only £8.

Thanks for the advice.