Cutting a paving slab

[Jimk]

For one? Just angle grind it.

I doubt you'll get a "perfect" edge whether you score it or go all the way. There'll either be a rough centre break &/or circular blade marks all along the cut.

Give it a season or two & you won't notice either unless the cut edge is really prominent.

[Bert Coules]

I have to make a single cut in a two inch thick basic concrete paving slab. I believe that dry power cutting is frowned on these days for the usual health and safety reasons, and it doesn't seem worthwhile to hire a wet cutter for a single slab, but I'd like to finish with as neat and clean an edge as possible and previous experience suggests that chiselling and hammering (even if the preliminary channels are made on both surfaces and both edges) won't necessarily provide that. Are there any handy tips for a neater result? Does the sharpness of the bolster chisel make any appreciable difference? Many thanks.

[alan_m]

Just use an angle grinder - it will take a few minutes and give you a clean cut.

[Bert Coules]

Thanks. Do you recommend trying to cut through the whole thickness, or using the angle grinder to groove right round and then applying pressure to snap the slab?

[David]

Will the cut edge be exposed to view?

If not, the roughness of the broken bit will be concealed anyway.

Cheers

Dave R

[Bert Coules]

I think it's unavoidable, yes. But even if not and I can arrange for the cut to butt up against another slab, I'd still like the cut edge to be neater than I've usually managed in the past. Probably just my incompetence but I'm unlikely to have improved, I suspect.

[spuorgelgoog]

Can you use a separate water sprayer (or garden hose)?

Owain

[David]

Are you breaking it over something? That is, cut the notch then place something (broom handle, bit os scrap wood) under the larger part so the waste is off the ground, then lean on the waste.

Similar to cutting tiles, allegedly it should then break off cleanly.

I stress the "allegedly".

Cheers

Dave R

[Chris Hogg]

My angle grinder didn't have the cutting depth to get more than about one third through the slabs I cut. Mark the line you want to cut with felt pen or whatever, on both sides of the slab. Angle grinder along the line, again on both sides. If it's a straight line, edge to edge say, then place slab over a broom handle, scaffolding pole or whatever, under the cut line and jump on it, one foot on either side of the line. If it's not a straight line, or involves two intersecting lines, gently tap along the cut with a bolster and club hammer until it cracks.

[tabbypurr]

The only way you'll get a neat cut is with an angle grinder. Wear a mask if worried about dust. Smacking it with a chisel will not succeed.

NT

[Roger Mills]

If you use a 9" angle grinder with a diamond-tipped cutting wheel you can go right through a 2" slab from one side. Use a mask and use the grinder the the right way up (moving the guard round if necessary) to ensure that the dust is directed *away* from you. Unless you're very skilled (which I'm not!) you may not end up with a completely straight and smooth cut - but it will be a *lot* better than using a chisel.

[Bert Coules]

Job done, angle-grindered (or perhaps angle-ground) on all four sides then gently bashed with a club hammer on a length of wood to spread the impact across the full width. Not a bad result, and as it turns out I can use the original good edge on the outside and mask the imperfections of my effort against another slab.

Thanks to everyone for the thoughts, advice, and encouragement.

NT: "Smashing it with a chisel" - nice turn of phrase.

[Bill Wright]

Cut all round using a diamond wheel. The snap. Then use the diamond wheel at a slight angle to tidy the rough edge where the break was.

Bill

[John Rumm]

Angle grinder, diamond blade, dust mask!

(if using a 4" machine you will need to cut both sides)

[John Rumm]

If you have access to a 9" grinder, then the technique I would use is to do one shallow straight pass, pulling the machine toward you to score the top surface (against a wooden batten if you want a really straight edge), then I follow up with a full depth pass pushing the machine away from me, but using the score a as a guide line to follow. That means all the dust is ejected down and under the slab (which needs to be raised on something) rather than straight at you.

[Brian Gaff (Sofa)]

Oh but the dust. You do need a mask and the usual eye protection of course, and maybe you need to be sure all your neighbours are out when you do it. Brian

[Brian Gaff (Sofa)]

Yes and ear defenders. I'm sure there a lot of partially deaf landscapers out there. Pardon, a quarter past three. Brian

[Bert Coules]

Brian, thanks for that. I did wear goggles over my glasses, but no mask: in the event, the job actually generated a lot less dust than I was expecting.