Thread: cutting concrete?

Originally Posted by dullbird

thank you crump...... an explaination!! us unintelligent people have a hard time reading more than 4 paragraphs

yep, well, I learnded sumfink from bein a sfetetey orificer.(no slight on WHSO's intended, I am one.)

I use demo saws (we refer to them as quick cuts) and 9" grinders regularly at work for cutting anything from door openings in brick walls to cutting up slabs. I point blank refuse to cut horrizontally (in a raised position) with the quick cut as I don't feel confident using it horrizontally. Im not comfortable with how you hold it horrizontally and the fact your body is allways on the same line as the blade (if it bits it may get you). When i was taught to use it I was told to always keep the cutting line away from your head and body so if it bites it wont catch you. The 9" grinders im quite happy to use in most places as they are easy to hold and its really a matter of common sense to ensure you don't injure yourself. For the sake of $200 odd dollars pay the professionals to do it. From all the things I've done in building so far I'd rate the quick cut then grinder as most dangerous tasks and still try to avoid if possible (try and con the boss into getting subbies to do it). Chances are if its the first time you've used the saw they're gonna do a lot neater job too. We use Sledgehammer here (Perth).

Originally Posted by disco_thrasher

standing up (in the ground)
__________________
Cheers,

Ben.


maybe you should read again,

and read the safety intruction on a demo saw about elevated use
i am a work place health and safety officer for a concrete company i work with this everyday ,look at the legislation and code of practice in using concrete cutting equipment ,IT IS UNSAFE TO USE A DEMO SAW ON A ELEVATED CUT

OK - before this goes any further - I am cutting the pipe off AT GROUND LEVEL (or at the level that my shed floor will be) - so no elevated cutting is involved.

And I have plenty of OH&S training so no issues there.

Originally Posted by p38arover

I read the "Need to cut the top off a 1200mm x 50mm wall concrete pipe.." to mean a 1200mm diameter x 50mm wall thickness pipe.

Ron

100% correct Ron - go to the top of the class - I thought I was making myself clear enough - obviously not.

Originally Posted by LandyAndy

Hi Ben
How neat does the cut need to be???
We either smash the ends off concreate culvert pipes with a big sledge hammer when out on the job.Then cut the wires with bolt cutters.
At the depot we use an air hammer with a chisel bit,a little slower but easier on the back and quite a bit neater.Bunnings sell ozito electric hammers for $100 that may do it,have a look.
If it has to be neat the cut-off saw is possibly your only option,scary machines to use,much more dangerous than a chainsaw especially at that height and on its side.
Get a price to have it cut,may not cost much more than hiring the gear.
Andrew

Hi Andy - I thought about doing it that way, but I would have to knock it off below the level of the shed floor, then put some formwork around the top and make it flush with the floor. Sounds like more work to me.

Originally Posted by Ben_R

Hi,
Having experience using both demo saws and 9inch grinders with diamond blades, I would use the grinder with diamond blade. Demo saws are hard enough to control safely even when cutting into concrete floor slabs let alone horizontial and off the ground.

I also took it to be a 1200mm dia pipe, 50mm thick. If this is the case, I would mark the line to be cut, grind through the perimter, being careful to leave four, 100mm sections to support the offcut, spaced evenly. Then securely pack out and support the cut sections either side of the remaining sections to be cut. Then go back and cut out those remaining sections away. You may need to prop the offcut in place, if it looks like it might shift while cutting away the remaining sections. This is assuming the offcut is large etc...

Alternatively, if the piece to be cut away is relatively small, mark the perimiter, grind down to that line, vertically in many places, to allow for small, easily handled pieces. Then go around and cut away the perimiter and just let the pieces fall in the pipe or on the ground.

Thats how I read the problem and I hope this may offer a solution.

cheers Ben

Thanks Ben - I think this is the way I will go.

you can buy a cutting disc for your portable saw which will cut concrete just take our your wood saw blade and replace much safer than a grinder

there is no leglislation in NSW reguarding the use of concrete cutting equipment, thats straight from the officers at WORKCOVER.
however there seem to be some leglislation in QLD, this im still checking into.