A walk-behind saw cuts slabs and roadway straight and deep, and the machine is the cheap half of the hire. Saws commonly advertise $90 to $200 a day depending on engine size, while the diamond blade is charged separately and can add $50 to $150 by the time it comes back measured. Cutting depth is fixed by blade diameter, so choose the blade first and the saw second.
Blade diameter sets the depth
Roughly, a saw cuts a little under half its blade diameter. A 14 inch blade gives about 4.5 to 5 inches, an 18 inch around 6.5, and a 20 inch about 7.5. A four inch residential slab is comfortable on a 14. A road or a footing needs the bigger machine, and cutting from both sides is slower and rarely straight.
How the blade is actually billed
Most yards measure the blade out and back and charge for the diamond consumed, which is why the return ticket differs from the quote. Green or abrasive concrete eats a blade quickly, and cutting rebar destroys the wrong one outright. Say whether the slab is reinforced and how old it is, then take the segment specification the counter recommends.
Wet cutting is the default for a reason
Water on the blade cools the diamond, doubles blade life and suppresses the silica dust that dry cutting throws. The construction dust rule names a water-fed saw with continuous flow as the control method for this work. That means a hose, a tank or a pressurised water buggy on site, and it means planning where the slurry runs before the first cut.
The saw does not do the corners
A walk-behind cannot finish an inside corner or start a cut in the middle of a slab, because the blade runs at a fixed height and the guard prevents plunge. Those bits are finished with a handheld cut-off saw or a chain saw with a concrete bar, both hired from the same counter, and both needing their own dust control.
Questions people ask about walk behind concrete saw rental
What size saw do I need for a four inch slab?
A 14 inch walk-behind handles it in one pass with room to spare. If the slab is a driveway apron or you cannot tell the thickness, take a saw that will accept an 18 inch blade so a deeper cut does not need a second hire.
Can a walk-behind saw cut through rebar?
Yes, with a blade specified for reinforced concrete. A blade meant for green or unreinforced concrete will lose segments on steel, and you will be billed for that blade, so declare the reinforcement when booking.
Electric or gas walk-behind saw?
Gas is standard outdoors and needs no power supply. Electric and hydraulic saws exist for indoor and enclosed work, where exhaust fumes are the deciding factor rather than cutting performance, and they need a suitable supply arranged in advance.