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.
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.
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.
On Sat, 09 Nov 2019 10:57:39 +0000, Bert Coules wrote:
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
Similar to cutting tiles, allegedly it should then break off cleanly.
I stress the "allegedly".
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64
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
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.
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.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.