Thread: cutting concrete?

not a sales man! im a fitter!
and i still cant seem to find any thing that says

IT IS UNSAFE TO USE A DEMO SAW ON A ELEVATED CUT

i do however find alot of dont use saw above sholder height (1.7m) or below knee height without employing SWM.

so if the pipe is 1200mm (im assuming thats the height out of the ground)
that would have to make you a very small man to be above shoulder height?
im 174cm and 120cm is smack bang in the middle of my chest?

Preparation:
• hand-hold for the operator’s non-trigger hand
should be present;
• suitable grips for both right and left handed
operators;
• saw should be as light as practicable for the
type of work, to reduce risk of strain injury;
• blade should be appropriately guarded;
• well balanced equipment should have antivibration
hand-grips that are comfortable to
use and provide sufficient support. (A poorly
balanced machine might require the
operator’s hands to be placed in dangerous
positions near the blade or vibrate
unnecessarily when in use, risking damage to
the operator’s circulation, nerves and joints);
• correct diamond cutting or abrasive
compound should be used for the material
being cut, as recommended by the
manufacturer, so the operator does not have
to force the cut;
• for horizontal cutting, the saw should be
capable of cutting right-to-left as well as leftto-
right without having to reposition the
blade or guard;
• automatic cut-off switch should be fitted;
• no modifications should have occurred from
its original manufactured form;
• establish that a pre-cut procedure is
developed for the site, which has been signed
off by the safety officer, electrician, plumber
and saw operator;
• check the original drawings and
“as-constructed” drawings (if they exist) as
well as the site for enclosed cables, wiring,
plumbing, steel reinforcing, structural stress
components;
• ensure if pipes are to be cut that they are
properly supported and chocked;
• inform others at the workplace that cutting or
drilling is about to begin;
• bunt off the area with “Noise Warning” and
“Danger Diamond Drilling” signs in
appropriate places;
• locate any persons assisting the operator
away from any danger of sudden saw
movements or ejection of material;
• fuelling should be done with the saw
switched off and well away from the work
area;
• fuelling to be done using a funnel, not direct
from a jerry can;
• check the cutting area has a clear working
surface;
• check the cutting area for ventilation. In
confined areas use a compressed air or
hydraulically-driven saw;
• if a petrol motor must be used in an enclosed
area, ensure a proper exhaust ventilation
system is provided;
• collect all slurry with a wet and dry vacuum
cleaner and dispose of it safely;
• no cutting above shoulder height. Anything
higher should be done from a platform or
scaffold;
• ensure hoses on hydraulic machines are
secure and oil levels in power packs are at
the correct levels;
• check ground conditions to ensure safe

footing for operator

now in 7 years at my ''sales'' job i have done numerous power tool training coarses and have never been told NOT to cut with a demo saw elevated.
if its too high i'll sell you an EWP or some scaffold, or a lanyard and a harness.

tomorrow i'll even ring DIMAS/partner/husquvana and stihl just to clear this up. because if i have been misinforming my customers i should at least get my facts straight.

Originally Posted by boxhead

I think that anything above 10 mm Det cord would be a quick way to do it and fairly cleanly




Adam

why not, this thread seems ready to explode.

thats because one of us has misinterpreted the wording of inverted with reguards to cutting concrete.

Inverted cutting – A major hazard

Never use a hand-held saw for inverted
cutting.
This is probably the most dangerous way of
all to use a hand-held concrete saw.
Inverted cutting entails using the top part
of the circular saw blade to cut under an
overhanging floor, ceiling or horizontal slab
of concrete or masonry.
Danger occurs because the top section of
the saw blade used for inverted cutting
moves away from the operator, greatly
increasing the risk of kick-back or pushback.
Inverted cutting also involves using the
front upper quadrant of the blade – the
blade’s highest-risk kick-back zone.
Kick-back becomes even more probable if
the concrete contains hidden obstructions
or resistance,e.g. from steel reinforcing rods
or mesh.
An additional hazard occurs when an
electric saw is used for inverted cutting.
Coolant water flowing into the motor can
cause electrocution.
The safest procedure is to always cut from

the top of a horizontal slab of concrete.

what about an abrasive grit water jet cutter? now they leave a reallly really nice cut and arent all that noisy.

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

Originally Posted by discowhite

thats because one of us has misinterpreted the wording of inverted with reguards to cutting concrete.

Inverted cutting – A major hazard

Never use a hand-held saw for inverted
cutting.
This is probably the most dangerous way of
all to use a hand-held concrete saw.
Inverted cutting entails using the top part
of the circular saw blade to cut under an
overhanging floor, ceiling or horizontal slab
of concrete or masonry.
Danger occurs because the top section of
the saw blade used for inverted cutting
moves away from the operator, greatly
increasing the risk of kick-back or pushback.
Inverted cutting also involves using the
front upper quadrant of the blade – the
blade’s highest-risk kick-back zone.
Kick-back becomes even more probable if
the concrete contains hidden obstructions
or resistance,e.g. from steel reinforcing rods
or mesh.
An additional hazard occurs when an
electric saw is used for inverted cutting.
Coolant water flowing into the motor can
cause electrocution.
The safest procedure is to always cut from

the top of a horizontal slab of concrete.

and no i do know what inverted means
i see you have done some research laws must be differnent down in NSW ,this is out of my book by QLD work place health and safety
Concrete wall cutters
This process is used for the cutting of openings in vertical surfaces and surfaces with slopes so great that flat saws [demo]can not be used. These surfaces are usually cut to provide for doors, windows, vaults, silos, chests, foundations, ducts or large diameter pipes, or to remove part or all of existing walls.
During cutting, ensure that:
when cutting horizontally across a wall, the operator’s hand are at waist height

http://www.deir.qld.gov.au/pdf/whs/c..._guide2001.pdf

second page.

Originally Posted by discowhite

so if the pipe is 1200mm (im assuming thats the height out of the ground).

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