A walk-behind saw is ideal for creating grooves and inlays into slabs of concrete. These saws are often used for trenching, patch repair, and other concrete and asphalt applications and are very effective on heavy concrete as well as stamped concrete.
If safety precautions are not taken seriously, walk-behind saws can be dangerous. Anyone operating a walk-behind saw must be trained and authorized before use.
Always wear proper PPE when operating any walk-behind saw. Wear eye protection, preferably goggles or safety glasses with side protection, and depending on the task, a face shield can provide additional protection. Wear closed-toed work shoes, with a good tread, for stability, preferably steel-toed boots. Additional PPE may be recommended, including work gloves, a dust mask, hearing protection, knee pads or shin protectors.
When operating an electric saw (as opposed to a gas-powered saw), use a GFCI-protected extension cord to protect against power surges, shocks and overloads.
Before using any walk-behind saw, first choose the correct blade necessary for the job. Always use the proper blade rated for the material you are cutting. Ensure the saw blade is clean and sharp. Dull or sticky blades are more likely to bind up in cuts. Remove cracked or damaged saw blades from service.
OSHA Standard 1926.300(b)(1) When power operated tools are designed to accommodate guards, they shall be equipped with such guards when in use.
After starting the engine, open the water valve to apply a wet cut, then adjust the blade slowly to the ground. The blade will slowly pull the saw forward. Slowly guide the saw with the cutting guide. Do not twist or change direction when making a cut. Making smooth cuts will ensure you don’t damage or break the blade. Stop the engine when leaving any walk-behind saw unattended.
Use the lifting bail and appropriate lifting equipment to ensure the safe movement or transport of the walk-behind saw. Do not use the handlebars or the front pointer as a lifting point. Never tow the saw behind a vehicle. The saw should never be transported with the blade mounted.
Gas-powered walk-behind saws give off deadly carbon monoxide gas and should never be used in any enclosed or narrow area where air flow is restricted. All fuel-powered tools emit carbon monoxide and represent a potentially fatal hazard when used in enclosed spaces. Always refuel in a well-ventilated area, away from sparks and open flames.
Only electric-powered concrete saws should be used in enclosed or narrow spaces. If a generator powers the electric saw, the generator must be placed outdoors, well away from the enclosed space.
Do not remove any instructional, operational or warning stickers or labels from the saw. If labels become worn or unreadable over time they should be replaced.
OSHA Standard 1926.302(c)(2) When fuel powered tools are used in enclosed spaces, the applicable requirements for concentrations of toxic gases and use of personal protective equipment shall apply.
Using a walk-behind saw to cut masonry, concrete, stone, or other silica-containing materials can generate respirable crystalline silica dust. When inhaled, the small particles of silica can irreversibly damage the lungs. The tool must be operated and maintained in accordance with manufacturer’s instructions to minimize dust.
Wet cutting is an effective method to reduce exposure to silica dust. Walk-behind saws should be equipped with an integrated water delivery system (commercially developed specifically for the type of tool in use) that continuously feeds water to the blade. The spray nozzles must not be clogged or damaged and must be working properly to apply water at the point of dust generation. All hoses and connections must be intact.
Full and proper implementation of water controls is required when using walk-behind saws. An adequate supply of water for dust suppression must be used.
OSHA Standard 1926.1153(c)(1) Table 1 provides specified exposure control methods when working with materials containing crystalline silica.
Where water is used to control dust, electrical safety is a particular concern. Use ground-fault circuit interrupters (GFCIs) and watertight, sealable electrical connectors for electric tools and equipment.
Walk-behind saws used to cut roads or pavement are typically used outdoors, though they can be used indoors to cut concrete floors. When walk-behind saws are used indoors, or in enclosed areas, additional exhaust must be provided to minimize visible airborne dust.
When employees are working outdoors, respiratory protection is not required for work with walk-behind saws, if proper wet-cutting procedures are being followed. When employees are working indoors, or in an enclosed location, respiratory protection with a minimum APF of 10 is required when using a walk-behind saw.
An indoor or enclosed location refers to any area where airborne dust can build up if forced ventilation isn’t used. Examples include:
- parking garages
- empty swimming pools
- open-top structures with 3 walls
- any other structure with limited air movement
Clean up any slurry produced during wet cutting to prevent the slurry from drying and releasing silica dust into the air. Wet slurry can be cleaned up using shovels or a vacuum equipped with a HEPA filter.