A joint saw is a wheeled power tool used by concrete and flooring professionals to cut neat expansion joints in concrete slabs.
Joint saws feature sturdy wheeled frames mounted on circular blades that cut concrete with electric or petrol motors. Their signature dust cowls connect to shop vacuums, allowing clean, dust-free indoor and outdoor operation.
Who Uses Joint Saws?
Joint saws like the JS203 and Diakat RK-10E are used by concrete contractors, stone/tile layers, flooring installation crews, and finish carpenters for horizontal concrete work.
The saw's wheeled precision proves superior to handheld tools for safely and efficiently executing neat control joints and removing old joint sealant. It is often the only tool that can provide cuts up to 90mm.
What Does a Joint Saw Do?
A joint saw's spinning concrete-cutting blade forms crisp expansion joints with set widths and depths in concrete floors. These control joints channel cracks to specific areas, preventing random slab cracking. Joint saws also efficiently clean out old joint sealant and prepare joints for fresh sealant installation. With the appropriate blades, joint saws can cut angles, channels, and grooves beyond straight joints.
Some models have water-fed guards with built-in sprinklers for wet-cutting applications. Wet cutting uses water to cool blades while significantly suppressing dangerous airborne dust - although dry joint saws also achieve excellent dust control with a vacuum system.
With a wet joint saw, the water-fed guard feeds a constant spray across the spinning blade and concrete for wet cuts. This water cools the high-speed blade, preventing overheating that causes premature wear. Cooler concrete cutting also requires less blade pressure.
Joint Saw Machine and Blade Specs
Joint saw blades range from 180mm to 300mm in diameter, accepting flat or angled "V" profile edges. Based on the blade size, operators can set precise cut depths up to 90mm. Electric models often utilise 180-225mm blades for 50mm cut depths, while more powerful petrol saws fit 300mm blades for 90mm cuts.
The wheeled chassis, adjustable pointer guides, and depth locks provide accuracy within 1/8 inch on straight cuts or removals.
Joint saws maintain a fixed cutting plane, quickly following floor variations that hamper handheld tools. Narrow speciality blades neatly channel cracks to specified areas.
When to Specify a Joint Saw
Professionals should specify joint saws over standard concrete saws for horizontal floor work requiring neat control joints or sealant removals. Handheld tools cannot match joint saws' safety, debris control, precision straight cuts, and expansion joint specialisation. Specify joint saws when cracking potential exists across large slab pours such as in warehouses, factories, distribution centres, and big box retail builds.
- Further reading
- https://www.hse.gov.uk/construction/healthrisks/hazardous-substances/cutting-paving-blocks-kerbs-and-flags.htm
- https://en.wikipedia.org/wiki/Expansion_joint
- https://www.pwm-sales.co.uk/the-benefits-of-joint-saws/
- https://www.pwm-sales.co.uk/petrol-or-electric-joint-saws/
- https://www.pwm-sales.co.uk/a-quick-guide-to-joint-saw-blades-and-blade-guards/
- https://www.pwm-sales.co.uk/how-joint-saws-work/