By Daniel Green
Since 6500BCE bedouin traders in what is now modern day Jordan first employed an early type of cement for their long term construction projects. Planning and execution of the pour was extremely important because back then they couldn’t exactly fire up the Tyrolit if the formworkers boxed up in the wrong place.
Luckily for us those days are long gone, because when there’s concrete to Ctrl Z there’s almost as many options than there are YouTube videos on construction fails. Concrete cutting is a highly technical exercise that can be fraught with danger. Blindsided by buried services, surprised by excess reo, starved by poor water supply and smoked out by exhaust fumes are just some of the hurdles to getting the job done. There’s also external factors: the depth of the cut, is the slab suspended or not, how to get the concrete out afterwards, the final finish, the timeline, other trades, weather changes and so on. So let’s start at the.. err.. start.
Army or Navy?
Dry Sawing. Reserved almost exclusively for outdoors, this aurally and spatially belligerent is process is far from delicate. Kinda like a platoon of soldiers: loud, dirty, messy and blundering their way through the job. The absence of water necessitates the need for expensive diamond blades. It’s also hard on the saw – meaning more frequent maintenance and therefore more cost. The sheer volume of dust is also tough on the operator and can require more frequent use of PPE. But in the absence of any water – this could be a good option.
Wet Sawing. This is where running water is introduced into the cut whether via a hose held by an offsider or plumbed through the saw itself. A quality branded saw has a water line that squirts the wet stuff onto the blade, complete with garden hose fitting. This means the water source can be a backpack sized mobile tank, a larger reservoir like a trailer-mounted tank or a household tap. The water acts as coolant and dust control, meaning both the operator and machine have to work less to achieve the same result. The only downside is that there must be a constant supply of H₂0 and that the runoff [known as slurry] needs to be collected. Wet sawing makes one helluva mess, so make sure you’re not afraid of the water before you sign up.
Demo Saws. Named for their frequent use in demolition, the demo saw is the AK47 of the concrete cutting arsenal. It’s very common, is extremely easy to use, is hard to kill and relatively cheap. It can cut to 125mm [or 5” in the old speak] using two-stroke power, meaning aural PPE is definitely required – even if you’re within 50m. It can also be kinda smoky and must be used in a well ventilated area or there’s the risk of carbon monoxide poisoning.
Ring Saws. When you need to cut greater than 125mm you can rely on the trusty ring saw. Titled because the blade is more akin to a frisbee ring than a traditional circular shaped saw, but the lack of a locating hub means you can cut down to 275mm or 11” – nearly a foot deep! Its kind of like the M16 – it’s got a bit more finesse than the Kalashnikov but needs a bit more care. With the average slab being 250mm thick the ring saw can combat almost any resi/commercial situation you throw at it. However, the initial ring saw investment is higher than the demo saw and this is reflected in the price per cut.
Electric Saws. When that smoky two stroke exhaust and motorcross-esque noise is a bit much then an electric saw is where its at. With an operating dB of only 90 [compared to the 104dB of a demo saw, which is actually fifty times louder!] and wet and dry cutting options, the electric saw is for when you need those behind-enemy-lines deals – tactical operations cuts where you’re in and out before they even realise. The only trick is that you may need your own 240v power source.
Hydraulic Saws. But what if you have to make a cut in a flammable area or in the middle of a flooded paddock or similarly tricky situation? Enter the hydraulic saw. Powered by a relatively low pressure hydraulic pump and genny, this rig is like the minigun of concrete saws. It will go and go and go until there’s nothing left to cut. The only disadvantage is that it could be tough if your cut is a long way from the genny and pump.
Flush Cut Saws. Every saw we’ve listed so far has had the blade in the centre of the saw – if you look at it from above. Even the narrowest of machines means that you cannot cut flush with any perpendicular surface. But what if the design calls for a doorway to be cut flush with the adjacent wall? World, meet the Barrett M50 Sniper Rifle flush cut saw. With the blade as the most extremity on one side of the machine, it can cut columns, beams and doorways flush with any adjacent surface.
Road Saws. Everyone has someone they call in an emergency. So when all the hand saws run and hide you can know the road saw is just around the corner. More akin to an M1 Abrams Main Battle Tank, this diesel-driven beast needs to be transported to site in a truck. But with a cutting depth of more than 600mm, when you need to cut deep – you cut with a road saw. The only trick to this guy is its size, manoeuvrability, weight and setup time.
Wall Saws. When the spec calls for a 600mm deep vertical cut spanning three metres with a polished concrete finish you’ve got a problem. Unless you know a concrete care specialist with a wall saw [hint: we know that exact someone!]. Like the famed Schwarer Gustav in WWII, this track mounted machine takes far more setup than any saw we’ve mentioned so far. But with a cut length only limited by the amount of track, a 650mm cutting depth and the ability to cut UPSIDE DOWN, when you need to cut dead straight – you call in the wall saw.
Wire Saws. Traditional saws are like traditional weapons – you know what you’re in for. What’s out of this world is the wire saw. Like the F-117 Stealth bomber, this bladeless, almost limitless concrete cutting machine utilises some alien tech to make cuts. Using a steel wire and a diamond-encrusted composite sleeve means this bad boy can cut almost any sized column, slab or wall and it can do it dead flush. Driven by a 20kW portable power unit, the only down side to the wire saw is it takes a bit of prep. So when the result is all that matters – the wire saw is where its at.
With a myriad of weaponry cutting implements in the Perfect Concrete Care arsenal, we feel confident we can help with virtually any situation you have. For more information, call Jaro Murgas on 0414 902 112.