Masonry skills are essential for plumbing professionals, particularly when installing pipework that requires solid structural support or when constructing water tanks, soak pits, or drainage channels. In Kenya, where many plumbing projects involve integration with building structures, understanding masonry enhances a plumber’s ability to collaborate effectively with masons and ensures installations are durable and compliant with construction standards. This chapter focuses on the safety hazards commonly encountered in masonry workshops and details the specific tools, equipment, and consumable materials used in masonry relevant to plumbing work.

2.1 Workshop safety hazards

In plumbing-related masonry work, safety in the workshop environment is paramount due to the use of heavy materials, sharp tools, and potentially hazardous substances such as cement and sand. Kenyan plumbing professionals must be aware of common hazards to prevent injuries and ensure compliance with occupational health and safety regulations, such as those outlined by the Directorate of Occupational Safety and Health Services (DOSHS). Identifying and mitigating these hazards fosters a safer working environment and reduces downtime caused by accidents.

2.1.1 Fire

Fire is a serious workshop hazard that can injure or kill workers and destroy tools, materials and buildings. A fire needs three things, together called the fire triangle: fuel, heat and oxygen, and removing any one puts it out. In masonry and plumbing workshops, fuels include timber formwork, packaging, fuel for generators and mixers, oily rags, solvents and gas cylinders, while heat comes from cutting, grinding, blowtorches, faulty wiring and smoking. Example: sparks from an angle grinder cutting steel reinforcement ignite cement bag paper and oily rags in a training workshop, but a trainee quickly puts out the small fire with a nearby extinguisher.

Causes of workshop fires

• Hot work: Sparks and flames from grinding, cutting, welding and blowtorches ignite nearby materials.
• Flammable liquids: Petrol, diesel and solvents spilled or stored carelessly catch fire easily.
• Electrical faults: Overloaded sockets, damaged cables and faulty equipment overheat.
• Combustible waste: Paper bags, timber offcuts and oily rags left lying around provide fuel.
• Smoking and naked flames: Cigarettes and matches near flammable materials start fires.

Fire prevention measures

• Fire Safety Measures: Knowledge of fire extinguisher locations and use, especially where flammable materials might be present.
• Control hot work: Clear combustible materials and keep an extinguisher nearby during cutting and heating.
• Store flammables safely: Keep fuels and solvents in labelled containers in a ventilated store away from heat.
• Maintain electrical equipment: Inspect cables and plugs and avoid overloading sockets.
• Remove waste regularly: Clear paper, timber and rags into metal bins.
• Ban smoking: Prohibit smoking and naked flames in the workshop.

Steps on discovering a fire

1. Raise the alarm: Shout "Fire!" and activate the alarm to warn everyone.
2. Assess the fire: Decide whether it is small enough to tackle safely.
3. Choose the correct extinguisher: Use the right type for the burning material.
4. Tackle small fires only: Attack from a safe position with an escape route behind you.
5. Evacuate if the fire grows: Leave immediately by the nearest safe exit.
6. Call emergency services: Report the fire and its location.
7. Assemble and account: Gather at the assembly point and check that everyone is present.

2.1.2 Explosion

An explosion is a sudden, violent release of energy that produces a blast, flying fragments and often fire. In workshops, explosions can result from leaking gas cylinders, overheated pressure vessels, compressed air equipment, flammable vapours and fine dust clouds. They cause severe burns, injuries from flying debris and building damage. Example: a leaking LPG cylinder used for heating bitumen in a poorly ventilated store allows gas to build up, which ignites when a light switch is turned on.

Causes of explosions

• Leaking gas cylinders: LPG and acetylene build up in enclosed spaces and ignite.
• Overpressurised vessels: Compressors, boilers and pressure tanks fail if valves are faulty.
• Flammable vapours: Vapours from petrol, solvents and paints ignite in confined spaces.
• Dust explosions: Fine combustible dust in the air ignites suddenly.
• Damaged cylinders and hoses: Dented cylinders, worn hoses and loose regulators leak or burst.

Prevention of explosions

• Store cylinders upright and secured: Chain cylinders in a ventilated, shaded area away from heat.
• Check for leaks: Test connections with soapy water, never with a flame.
• Maintain pressure equipment: Service compressors and fit working safety valves.
• Ventilate workshops: Prevent build-up of gases and vapours.
• Control ignition sources: Keep sparks, flames and smoking away from flammable materials.
• Train workers: Teach safe handling of cylinders and pressure equipment.

2.1.3 Fumes and gases

Fumes and gases are airborne substances that can be breathed in, causing irritation, poisoning, lung disease or death. In masonry and plumbing workshops they come from engine exhausts, welding and cutting, solvents and adhesives, and fine dust from cement, sand and cutting blocks. Their effects may be immediate, such as dizziness from carbon monoxide, or develop slowly, such as lung disease from years of dust exposure. Example: a petrol-driven mixer run inside a closed workshop fills the room with carbon monoxide, causing two workers to feel dizzy before the doors are opened.

Sources of fumes, gases and dust

• Dust inhalation: Cement and sand dust can irritate the respiratory system, leading to conditions such as silicosis or chronic bronchitis, especially without proper respiratory protection.
• Cement dust exposure: Prolonged inhalation of cement dust can cause lung diseases and skin irritation; wet cement may cause chemical burns.
• Silica dust: Sand used in mortar contains silica, which is hazardous when inhaled in fine particles, necessitating dust control measures.
• Engine exhaust: Generators, mixers and compressors give off carbon monoxide.
• Welding and cutting fumes: Metal fumes and gases from hot work.
• Solvents and adhesives: Vapours from solvent cements, paints and cleaning agents.
• Sewer gases: Hydrogen sulphide and methane from drains and manholes.

Control measures

• Dust masks or respirators: Reduce inhalation of hazardous dust, especially in poorly ventilated areas.
• Ventilation: Open doors and windows and use extract fans.
• Run engines outdoors: Never operate fuel-driven equipment inside closed spaces.
• Wet cutting: Use water when cutting blocks and stone to reduce dust.
• Use low-emission products: Choose water-based or low-solvent materials.
• Monitor confined spaces: Test the air before entering manholes and tanks.

Worked example: ventilation airflow needed

Airflow = room volume × air changes per hour

A workshop is 12 m long, 8 m wide and 4 m high and needs 6 air changes per hour during cutting work.

Room volume = 12 × 8 × 4 = 384 m³

Airflow = 384 × 6 = 2,304 m³ per hour

2.1.4 Electric shock

Electric shock occurs when electric current passes through the body, which can cause burns, muscle spasms, falls, heart failure and death. Workshops use many electric tools, such as drills, mixers, grinders and extension leads, often near water and wet cement, which greatly increases the risk. Example: a trainee using a drill with a damaged cable while standing on a wet floor receives a shock, but a residual current device switches off the power before serious injury.

Causes of electric shock

• Damaged cables and plugs: Exposed wires touched by hands or tools.
• Wet conditions: Water and wet concrete conduct electricity.
• Faulty tools: Damaged insulation or internal faults in equipment.
• Overloaded sockets: Overheating damages insulation.
• Drilling into hidden cables: Striking live wiring in walls or floors.

Prevention of electric shock

• Inspect tools before use: Check cables, plugs and casings for damage.
• Use residual current devices: Fit RCDs that cut power quickly if current leaks.
• Keep electrics dry: Keep cables and tools away from water and wet mortar.
• Use low-voltage tools: Use battery or reduced-voltage tools in wet areas.
• Locate cables before drilling: Use a cable detector before drilling walls.
• Leave repairs to electricians: Only qualified persons should repair electrical equipment.

Steps for helping a person receiving an electric shock

1. Do not touch the person: Touching them could pass the current to you.
2. Switch off the power: Turn off at the switch, plug or main isolator.
3. Separate with an insulator: If power cannot be switched off, use dry wood or plastic to move the source away.
4. Call for help: Summon a first aider and emergency services.
5. Check breathing: Check whether the person is breathing and responsive.
6. Give first aid: Start CPR if trained and needed, and treat burns.
7. Report the incident: Record and report the accident and have the equipment checked.

2.1.5 Spilt oil/water

Spilt oil and water make workshop floors slippery and are a major cause of slips and falls. Oil leaks from machines, diesel spills at refuelling, water from mixing, washing and curing, and wet cement or slurry all create hazards. Spills can also damage equipment, reach electrical points and pollute drains and soil. Example: diesel spilt while refuelling a mixer spreads across a training yard, and a trainee carrying blocks slips, until the area is covered with sand and cleaned.

Hazards from spills

• Slips, trips, and falls: Wet cement, sand spillage, and uneven floors increase the risk of slipping or tripping, potentially resulting in sprains or fractures.
• Fire risk: Oil and fuel spills can ignite.
• Electrical danger: Water spreading to sockets and cables can cause shocks.
• Damage to materials: Water spoils cement bags and other materials.
• Environmental pollution: Oil entering drains contaminates water and soil.

Prevention of spills

• Maintaining clean work areas: Reduces slip and trip hazards by promptly cleaning spills and organizing tools and materials.
• Maintain machines: Repair oil leaks on mixers, compressors and generators.
• Refuel carefully: Use funnels and drip trays when refuelling.
• Control water use: Mix and wash in designated areas with drainage.
• Use non-slip flooring: Provide rough or anti-slip surfaces in wet areas.

Steps for cleaning up an oil or water spill

1. Warn others: Place warning signs or cones around the spill.
2. Stop the source: Switch off or close leaking machines, taps or containers.
3. Contain the spill: Use absorbent material, sand or booms to stop it spreading.
4. Absorb or mop: Absorb oil with sawdust, sand or absorbent pads and mop water.
5. Dispose of waste properly: Place oily absorbents in labelled containers for safe disposal.
6. Clean the surface: Wash with detergent to remove remaining residue.
7. Dry the area: Ensure the floor is dry before removing signs.
8. Report the spill: Record the incident and fix the cause.

2.1.6 Other physical hazards in masonry workshops

Physical hazards in masonry workshops pose significant risks to plumbing professionals, especially during the mixing and handling of masonry materials or when working near heavy equipment. Recognizing these hazards is the first step in accident prevention.

• Falling objects: Bricks, blocks, or tools can fall from stacks or scaffolding, causing injuries such as fractures or head trauma.
• Manual handling injuries: Lifting heavy bricks or bags of cement improperly can cause musculoskeletal injuries, particularly back strain.
• Sharp tools: Trowels, chisels, and other sharp masonry tools can cause cuts or puncture wounds if not handled carefully.

2.1.7 Other chemical and environmental hazards

Masonry work involves exposure to chemicals and environmental factors that may affect health if precautions are not taken. Plumbing professionals must understand these risks to use protective measures effectively.

• Noise pollution: Use of power tools such as mixers or cutting machines can expose workers to harmful noise levels, risking hearing loss.
• Heat stress: Working in direct sunlight or poorly ventilated workshops can cause dehydration and heat-related illnesses.
• Chemical additives: Some mortar mixes contain additives or bonding agents that may cause allergic reactions or skin sensitization.

2.1.8 Safety practices and personal protective equipment (PPE)

Implementing safety practices and using appropriate PPE are critical to minimizing risks in masonry workshops. Plumbing professionals must adopt these measures to protect themselves and those around them.

• Wearing helmets and safety boots: Protects against falling objects and foot injuries from heavy materials.
• Using gloves and eye protection: Prevents skin irritation from cement and protects eyes from dust or flying debris.
• Proper lifting techniques: Training on ergonomics to avoid back injuries during manual handling.

2.1.9 Emergency preparedness and hazard reporting

Effective emergency preparedness and prompt reporting of hazards are crucial in managing risks in masonry workshops. Plumbing professionals must be familiar with emergency procedures to respond appropriately.

• First aid availability: Ensuring first aid kits are stocked and accessible in the workshop.
• Clear evacuation routes: Keeping exits unobstructed and well marked for quick evacuation.
• Hazard reporting systems: Encouraging workers to report unsafe conditions or incidents promptly to supervisors.
• Regular safety drills: Conducting drills to prepare workers for emergencies such as fires or accidents involving hazardous substances.

Chapter Summary

This chapter covered essential aspects of demonstrating masonry skills, beginning with the identification and understanding of common workshop safety hazards such as fire, explosion, fumes and gases, electric shock, and spilt oil or water. It then detailed the various masonry tools, equipment, and consumable materials necessary for effective work, including wire brushes, saws, hammers, trowels, mason squares, builder's lines, tape measures, spirit levels, floats, shovels, plumb bobs, drilling machines, and wheelbarrows. The chapter also explained the importance of working drawings, highlighting structural, architectural, mechanical, and electrical plans as critical guides in construction projects. Setting out procedures were discussed to ensure accurate layout and measurement before masonry work begins. The core masonry procedures were outlined, emphasizing the correct methods and sequences for building strong and durable structures. Different masonry work finishes were described to achieve both functional and aesthetic objectives. Finally, the chapter examined functionality tests used to verify the quality and reliability of masonry work before project completion.