Red Seal CCW cheat sheet

Hierarchy of controls, most to least effective: elimination, substitution, engineering controls, administrative controls, personal protective equipment.

Four classes of fall protection: guardrails, personal fall-arrest systems, safety nets, and travel-restraint systems; fall arrest requires a rescue plan before work starts.

Fall-arrest anchor strength: 22 kN (5,000 lbf) per worker for engineered anchors; free-fall distance kept under 1.8 m (6 ft) where practicable.

Respirable crystalline silica: workplace exposure limit commonly 0.025 mg/m3 (8-hour TWA) in Ontario; wet cutting and local exhaust ventilation are primary controls.

Confined-space entry requires a hazard assessment, entry permit, atmospheric testing (oxygen 19.5-23%), attendant, and rescue provisions before entry.

Hazardous energy control (lockout/tagout): isolate, lock, tag, verify zero energy by test, and confirm stored energy is released before work.

Noise: hearing protection required at 85 dBA Lex 8-hour; exposure limit 85 dBA in most Canadian jurisdictions; double protection above 105 dBA.

WHMIS 2016: pictograms, supplier labels, and safety data sheets with 16 sections; worker training required before handling a controlled product.

Incident reporting: report serious injuries and critical injuries to the regulator immediately; preserve the scene unless rescue or safety requires changes.

Erosion and sediment controls: silt fence, straw bale barriers, sediment traps, and check dams installed before grading; inspect after every rain event.

Silt fence placement: on the contour, keyed into the ground, with the fabric on the uphill side; not used in concentrated flow channels.

Spill response sequence: stop the source, contain with absorbent or berm, protect drains and watercourses, notify, and dispose of waste per regulation.

Designated substances and asbestos: suspect materials tested before disturbance; asbestos work follows jurisdiction-specific licensing and notification rules.

Waste segregation: separate clean fill, recyclable metals, wood, gypsum, and hazardous waste (paints, solvents, fuels) to meet diversion requirements.

Fuel storage: secondary containment sized to at least 110% of the largest container; drip trays under refuelling points.

Dust suppression: water carts or applied water on unpaved haul roads; visible dust from a site boundary is a common compliance trigger.

Protected trees: establish a tree protection zone at the drip line or per arborist plan; no storage, parking, or excavation inside it.

Benchmark (BM) is a fixed elevation reference; a temporary benchmark (TBM) is established on site and tied to the BM.

Differential levelling: HI = backsight reading + known elevation; unknown elevation = HI minus foresight reading. Arithmetic check: sum BS - sum FS = last RL - first RL.

3-4-5 method: a triangle with sides 3, 4, and 5 units has a 90-degree angle between the 3 and 4 sides; scale to 6-8-10 or 9-12-15 for larger layouts.

Building layout: set batter boards beyond excavation limits, stretch string lines, and transfer corners with a plumb bob or laser; confirm diagonals are equal for squareness.

Slope expressed as percent grade = (rise / run) x 100; a 2% slope drops 0.02 m per 1 m of horizontal run.

Station and offset notation: station is distance along a baseline, offset is perpendicular distance left or right; used to set utilities and structures.

Total station setup: occupy a known point, backsight a second known point, then check a third known point to verify angular closure before staking.

Site stripping: topsoil removed to a defined depth and stockpiled separately for later reuse in landscaping and restoration.

Trench definition: depth greater than width, and width at the bottom 2 m (6 ft) or less; deeper than 1.2 m (4 ft) requires a protective system in most Canadian jurisdictions.

Soil types: Type 1 (hard, stable), Type 2 (stiff, cohesive), Type 3 (soft, disturbed), Type 4 (running, submerged); each type sets maximum slope angles and shoring requirements.

Sloping for protection: Type 1 about 3/4:1, Type 2 about 1:1, Type 3 about 1.5:1, Type 4 requires engineering; verify against the local regulation table.

Spoil and equipment kept back at least 1 m (3 ft) from the trench edge; ladders within 7.5 m (25 ft) of travel for worker access and egress.

Locate buried utilities before digging by calling the provincial one-call service and hand exposing within the tolerance zone; never machine dig near marked lines.

Daily and post-rain inspection by a competent person: check for tension cracks, sloughing, water accumulation, and spoil loading at the crest.

Trench boxes: installed so the top is above grade and the bottom is within 0.6 m (2 ft) of the trench bottom; workers stay inside the box during hoisting.

Atmospheric testing before entry: oxygen 19.5-23%, combustible gas below 10% LEL, and toxic gases below exposure limits; continue monitoring while occupied.

Concrete mix ratio by volume for general work: 1 part cement, 2 parts sand, 3 parts coarse aggregate; water-cement ratio controls strength and durability.

Formwork design loads: concrete weight about 24 kN/m3 (150 lb/ft3), plus live load, impact, and lateral pressure from fresh concrete.

Formwork removal: sides of non-load-bearing forms after concrete is hard enough not to be damaged; soffits and props only after the specified strength is reached (commonly 70% of design strength for slabs).

Slump test measures workability; typical structural range 75-125 mm; test per CSA A23.2 on a sample from the middle of the load.

Curing: keep concrete moist and above 5 degrees C for at least 7 days (Type 1 cement) or per specification; cold weather requires insulation and temperature records.

Formwork ties and bracing: snap ties rated for the lateral pressure; vertical and diagonal bracing to resist wind and placement forces.

Control joints are sawn or formed to a depth of about 1/4 slab thickness to control random cracking; spacing typically 24-36 times slab thickness.

Concrete placement: free fall limited to about 1.5 m (5 ft) to prevent segregation; vibrate systematically without over-vibration.

Mortar types: M (high strength, 2500 psi), S (medium-high, 1800 psi), N (general purpose, 750 psi), O (low strength, 350 psi); S or N common for exterior load-bearing walls.

Standard modular brick: 90 mm x 57 mm x 190 mm face dimensions with 10 mm mortar joints; nominal module 200 mm x 67 mm x 200 mm.

Running bond: each course offset half a brick; common bond has header courses every fifth or sixth course; English bond alternates stretcher and header courses.

Wall ties: corrosion-resistant ties spaced at 600 mm horizontally and 400 mm vertically for cavity walls, with one tie per 0.25 m2 of wall area.

Flashing and weepholes: weepholes spaced at 800 mm (32 in) maximum and at 600 mm (24 in) near lintels; flashing lapped and terminated with a drip edge.

Lintel bearing: typically 100 mm (4 in) minimum bearing each side for masonry lintels; verify with the structural design.

Masonry grout: slump 200-275 mm for reinforced hollow block; consolidation by puddling or mechanical vibration to fill voids.

Scaffold for masonry: working platform width at least 500 mm (20 in), fully planked, with guardrails at 1 m and 2 m and toe boards.

Nominal to actual lumber: 2x4 is 38 x 89 mm, 2x6 is 38 x 140 mm, 2x10 is 38 x 235 mm; dressed dimensions govern spans and loads.

Floor joist spans are tabulated by species, grade, size, spacing, and live load; never overspan without checking the span table or engineer.

Bearing and notching: a notch in the top of a joist limited to 1/4 depth at the ends and 1/6 depth in the middle third; holes kept to the middle third of depth.

Stud spacing: 400 mm (16 in) or 600 mm (24 in) on centre; load-bearing walls require a double top plate and full bearing under headers.

Header sizing: opening width plus 75 mm (3 in) bearing each side; header depth increases with span and load; jack and king studs flank the opening.

Roof pitch = rise / run; a 4/12 pitch rises 4 units per 12 units of run, giving an angle of about 18.4 degrees.

Rafter length = run / cos(pitch angle); multiply the run by the pitch factor for the common rafter length.

Truss installation: follow the truss layout drawing, brace per the truss designer, and never cut or notch truss members without engineering approval.

Sheathing fastening: panel edges supported and nailed at 150 mm (6 in) on centre, field nails at 300 mm (12 in) on centre for subfloor, per the schedule.

Sling angle effect: tension = load / (number of legs x sin of the angle to horizontal); at 30 degrees, each leg carries the full load, at 60 degrees about 0.58 of the load.

Load centre of gravity must be below the hook for a stable lift; tag lines control rotation and are never wrapped around hands or body.

Rigging inspection: remove slings with broken wires, kinks, cuts, or missing tags; wire rope removal criteria include 10 randomly distributed broken wires in one lay.

Rated capacity of a sling is reduced by the splice, hardware, and configuration; never exceed the manufacturer's tag rating.

Crane hand signals: standardized signals used by a designated signaller; stop signal is one arm extended palm down, moving arm side to side.

Outrigger setup: fully extended on stable bearing pads; verify ground bearing capacity and keep clear of excavations and underground services.

Rigging hardware: shackles, hooks, and swivels rated with a proof load and marked; hooks with cracks or more than 10% throat opening deformation are removed.

Load weight estimate: steel 7850 kg/m3, concrete 2400 kg/m3, wood (softwood) about 500 kg/m3; volume times density gives mass.

Guards on circular saws return to cover the blade automatically; the riving knife is set within 5 mm of the blade and no higher than the blade top.

Abrasive wheels: ring test before mounting; match wheel speed rating to the tool; guard covers at least half the wheel and the tool has a dead-man switch.

Powder-actuated tools: operator certified, eye and hearing protection, and the tool never loaded until immediately before use; misfire held down for 30 seconds.

Compressors and air tools: hose whip checks at every connection; never exceed the tool's rated pressure; drain receiver tanks regularly.

Ladder setup: 4:1 rule, one unit of horizontal distance for every four units of vertical height; extend 1 m (3 ft) above the landing for access.

Scaffold inspection: check sills, base plates, plumb, bracing, planks, guardrails, and ties before each shift and after alteration or high wind.

Fuel-powered equipment: never refuel a hot engine or in an enclosed space; store fuel in approved containers away from ignition sources.

Lockout applies to maintenance: de-energize, isolate, lock, tag, and verify the equipment cannot start before removing guards or clearing jams.

Pre-demolition survey: identify hazardous materials (asbestos, lead paint, PCBs), structural load paths, and utilities; disconnect and cap services before demolition.

Demolition sequence generally works top-down and from the least to most stable elements; never undercut a wall or leave unsupported masonry above a work area.

Designated substance survey before renovation: test suspect materials for asbestos and lead; abatement by qualified workers with air monitoring before general demolition.

Lead paint removal from a building constructed before 1980 requires controls: containment, HEPA vacuum, wet methods, and personal exposure monitoring.

Chimney demolition: remove from the top down in sections; do not topple a chimney onto a structure, and brace it during removal.

Debris removal: chutes or covered openings for material above one storey; drop zones barricaded and controlled by a spotter.

Site cleanup: remove debris daily, keep walkways clear, and separate waste streams for recycling and disposal records.

Burning is prohibited on construction sites in most jurisdictions; debris is hauled to an approved disposal or recycling facility.

Contract documents hierarchy: agreement, general conditions, supplementary conditions, specifications, drawings, and addenda; the order of precedence is stated in the contract.

A request for information (RFI) documents a clarification; a change order is a written, signed modification to scope, price, or schedule; never proceed on verbal direction alone.

Shop drawings are contractor-prepared detail drawings submitted for design review; approval does not relieve the contractor of contract compliance.

Site diary entries: date, weather, crew and equipment on site, work performed, visitors, delays, deliveries, and instructions received, recorded the same day.

Field instruction and site instruction records: written confirmation of verbal directions issued within 24-48 hours to preserve claims.

As-built drawings record actual installed conditions and must be updated throughout construction, not reconstructed at the end of the project.

Progress reporting: percent complete by cost or by quantity installed; compare against the baseline schedule and flag variance early.

Professional practice: only perform work within trade certification and scope; report unsafe conditions; keep client and employer information confidential.

Hierarchy of controls, most to least effective: elimination, substitution, engineering controls, administrative controls, personal protective equipment.

Four classes of fall protection: guardrails, personal fall-arrest systems, safety nets, and travel-restraint systems; fall arrest requires a rescue plan before work starts.

Fall-arrest anchor strength: 22 kN (5,000 lbf) per worker for engineered anchors; free-fall distance kept under 1.8 m (6 ft) where practicable.

Respirable crystalline silica: workplace exposure limit commonly 0.025 mg/m3 (8-hour TWA) in Ontario; wet cutting and local exhaust ventilation are primary controls.

Confined-space entry requires a hazard assessment, entry permit, atmospheric testing (oxygen 19.5-23%), attendant, and rescue provisions before entry.

Hazardous energy control (lockout/tagout): isolate, lock, tag, verify zero energy by test, and confirm stored energy is released before work.

Noise: hearing protection required at 85 dBA Lex 8-hour; exposure limit 85 dBA in most Canadian jurisdictions; double protection above 105 dBA.

WHMIS 2016: pictograms, supplier labels, and safety data sheets with 16 sections; worker training required before handling a controlled product.

Incident reporting: report serious injuries and critical injuries to the regulator immediately; preserve the scene unless rescue or safety requires changes.

Erosion and sediment controls: silt fence, straw bale barriers, sediment traps, and check dams installed before grading; inspect after every rain event.

Silt fence placement: on the contour, keyed into the ground, with the fabric on the uphill side; not used in concentrated flow channels.

Spill response sequence: stop the source, contain with absorbent or berm, protect drains and watercourses, notify, and dispose of waste per regulation.

Designated substances and asbestos: suspect materials tested before disturbance; asbestos work follows jurisdiction-specific licensing and notification rules.

Waste segregation: separate clean fill, recyclable metals, wood, gypsum, and hazardous waste (paints, solvents, fuels) to meet diversion requirements.

Fuel storage: secondary containment sized to at least 110% of the largest container; drip trays under refuelling points.

Dust suppression: water carts or applied water on unpaved haul roads; visible dust from a site boundary is a common compliance trigger.

Protected trees: establish a tree protection zone at the drip line or per arborist plan; no storage, parking, or excavation inside it.

Benchmark (BM) is a fixed elevation reference; a temporary benchmark (TBM) is established on site and tied to the BM.

Differential levelling: HI = backsight reading + known elevation; unknown elevation = HI minus foresight reading. Arithmetic check: sum BS - sum FS = last RL - first RL.

3-4-5 method: a triangle with sides 3, 4, and 5 units has a 90-degree angle between the 3 and 4 sides; scale to 6-8-10 or 9-12-15 for larger layouts.

Building layout: set batter boards beyond excavation limits, stretch string lines, and transfer corners with a plumb bob or laser; confirm diagonals are equal for squareness.

Slope expressed as percent grade = (rise / run) x 100; a 2% slope drops 0.02 m per 1 m of horizontal run.

Station and offset notation: station is distance along a baseline, offset is perpendicular distance left or right; used to set utilities and structures.

Total station setup: occupy a known point, backsight a second known point, then check a third known point to verify angular closure before staking.

Site stripping: topsoil removed to a defined depth and stockpiled separately for later reuse in landscaping and restoration.

Trench definition: depth greater than width, and width at the bottom 2 m (6 ft) or less; deeper than 1.2 m (4 ft) requires a protective system in most Canadian jurisdictions.

Soil types: Type 1 (hard, stable), Type 2 (stiff, cohesive), Type 3 (soft, disturbed), Type 4 (running, submerged); each type sets maximum slope angles and shoring requirements.

Sloping for protection: Type 1 about 3/4:1, Type 2 about 1:1, Type 3 about 1.5:1, Type 4 requires engineering; verify against the local regulation table.

Spoil and equipment kept back at least 1 m (3 ft) from the trench edge; ladders within 7.5 m (25 ft) of travel for worker access and egress.

Locate buried utilities before digging by calling the provincial one-call service and hand exposing within the tolerance zone; never machine dig near marked lines.

Daily and post-rain inspection by a competent person: check for tension cracks, sloughing, water accumulation, and spoil loading at the crest.

Trench boxes: installed so the top is above grade and the bottom is within 0.6 m (2 ft) of the trench bottom; workers stay inside the box during hoisting.

Atmospheric testing before entry: oxygen 19.5-23%, combustible gas below 10% LEL, and toxic gases below exposure limits; continue monitoring while occupied.

Concrete mix ratio by volume for general work: 1 part cement, 2 parts sand, 3 parts coarse aggregate; water-cement ratio controls strength and durability.

Formwork design loads: concrete weight about 24 kN/m3 (150 lb/ft3), plus live load, impact, and lateral pressure from fresh concrete.

Formwork removal: sides of non-load-bearing forms after concrete is hard enough not to be damaged; soffits and props only after the specified strength is reached (commonly 70% of design strength for slabs).

Slump test measures workability; typical structural range 75-125 mm; test per CSA A23.2 on a sample from the middle of the load.

Curing: keep concrete moist and above 5 degrees C for at least 7 days (Type 1 cement) or per specification; cold weather requires insulation and temperature records.

Formwork ties and bracing: snap ties rated for the lateral pressure; vertical and diagonal bracing to resist wind and placement forces.

Control joints are sawn or formed to a depth of about 1/4 slab thickness to control random cracking; spacing typically 24-36 times slab thickness.

Concrete placement: free fall limited to about 1.5 m (5 ft) to prevent segregation; vibrate systematically without over-vibration.

Mortar types: M (high strength, 2500 psi), S (medium-high, 1800 psi), N (general purpose, 750 psi), O (low strength, 350 psi); S or N common for exterior load-bearing walls.

Standard modular brick: 90 mm x 57 mm x 190 mm face dimensions with 10 mm mortar joints; nominal module 200 mm x 67 mm x 200 mm.

Running bond: each course offset half a brick; common bond has header courses every fifth or sixth course; English bond alternates stretcher and header courses.

Wall ties: corrosion-resistant ties spaced at 600 mm horizontally and 400 mm vertically for cavity walls, with one tie per 0.25 m2 of wall area.

Flashing and weepholes: weepholes spaced at 800 mm (32 in) maximum and at 600 mm (24 in) near lintels; flashing lapped and terminated with a drip edge.

Lintel bearing: typically 100 mm (4 in) minimum bearing each side for masonry lintels; verify with the structural design.

Masonry grout: slump 200-275 mm for reinforced hollow block; consolidation by puddling or mechanical vibration to fill voids.

Scaffold for masonry: working platform width at least 500 mm (20 in), fully planked, with guardrails at 1 m and 2 m and toe boards.

Nominal to actual lumber: 2x4 is 38 x 89 mm, 2x6 is 38 x 140 mm, 2x10 is 38 x 235 mm; dressed dimensions govern spans and loads.

Floor joist spans are tabulated by species, grade, size, spacing, and live load; never overspan without checking the span table or engineer.

Bearing and notching: a notch in the top of a joist limited to 1/4 depth at the ends and 1/6 depth in the middle third; holes kept to the middle third of depth.

Stud spacing: 400 mm (16 in) or 600 mm (24 in) on centre; load-bearing walls require a double top plate and full bearing under headers.

Header sizing: opening width plus 75 mm (3 in) bearing each side; header depth increases with span and load; jack and king studs flank the opening.

Roof pitch = rise / run; a 4/12 pitch rises 4 units per 12 units of run, giving an angle of about 18.4 degrees.

Rafter length = run / cos(pitch angle); multiply the run by the pitch factor for the common rafter length.

Truss installation: follow the truss layout drawing, brace per the truss designer, and never cut or notch truss members without engineering approval.

Sheathing fastening: panel edges supported and nailed at 150 mm (6 in) on centre, field nails at 300 mm (12 in) on centre for subfloor, per the schedule.

Sling angle effect: tension = load / (number of legs x sin of the angle to horizontal); at 30 degrees, each leg carries the full load, at 60 degrees about 0.58 of the load.

Load centre of gravity must be below the hook for a stable lift; tag lines control rotation and are never wrapped around hands or body.

Rigging inspection: remove slings with broken wires, kinks, cuts, or missing tags; wire rope removal criteria include 10 randomly distributed broken wires in one lay.

Rated capacity of a sling is reduced by the splice, hardware, and configuration; never exceed the manufacturer's tag rating.

Crane hand signals: standardized signals used by a designated signaller; stop signal is one arm extended palm down, moving arm side to side.

Outrigger setup: fully extended on stable bearing pads; verify ground bearing capacity and keep clear of excavations and underground services.

Rigging hardware: shackles, hooks, and swivels rated with a proof load and marked; hooks with cracks or more than 10% throat opening deformation are removed.

Load weight estimate: steel 7850 kg/m3, concrete 2400 kg/m3, wood (softwood) about 500 kg/m3; volume times density gives mass.

Guards on circular saws return to cover the blade automatically; the riving knife is set within 5 mm of the blade and no higher than the blade top.

Abrasive wheels: ring test before mounting; match wheel speed rating to the tool; guard covers at least half the wheel and the tool has a dead-man switch.

Powder-actuated tools: operator certified, eye and hearing protection, and the tool never loaded until immediately before use; misfire held down for 30 seconds.

Compressors and air tools: hose whip checks at every connection; never exceed the tool's rated pressure; drain receiver tanks regularly.

Ladder setup: 4:1 rule, one unit of horizontal distance for every four units of vertical height; extend 1 m (3 ft) above the landing for access.

Scaffold inspection: check sills, base plates, plumb, bracing, planks, guardrails, and ties before each shift and after alteration or high wind.

Fuel-powered equipment: never refuel a hot engine or in an enclosed space; store fuel in approved containers away from ignition sources.

Lockout applies to maintenance: de-energize, isolate, lock, tag, and verify the equipment cannot start before removing guards or clearing jams.

Pre-demolition survey: identify hazardous materials (asbestos, lead paint, PCBs), structural load paths, and utilities; disconnect and cap services before demolition.

Demolition sequence generally works top-down and from the least to most stable elements; never undercut a wall or leave unsupported masonry above a work area.

Designated substance survey before renovation: test suspect materials for asbestos and lead; abatement by qualified workers with air monitoring before general demolition.

Lead paint removal from a building constructed before 1980 requires controls: containment, HEPA vacuum, wet methods, and personal exposure monitoring.

Chimney demolition: remove from the top down in sections; do not topple a chimney onto a structure, and brace it during removal.

Debris removal: chutes or covered openings for material above one storey; drop zones barricaded and controlled by a spotter.

Site cleanup: remove debris daily, keep walkways clear, and separate waste streams for recycling and disposal records.

Burning is prohibited on construction sites in most jurisdictions; debris is hauled to an approved disposal or recycling facility.

Contract documents hierarchy: agreement, general conditions, supplementary conditions, specifications, drawings, and addenda; the order of precedence is stated in the contract.

A request for information (RFI) documents a clarification; a change order is a written, signed modification to scope, price, or schedule; never proceed on verbal direction alone.

Shop drawings are contractor-prepared detail drawings submitted for design review; approval does not relieve the contractor of contract compliance.

Site diary entries: date, weather, crew and equipment on site, work performed, visitors, delays, deliveries, and instructions received, recorded the same day.

Field instruction and site instruction records: written confirmation of verbal directions issued within 24-48 hours to preserve claims.

As-built drawings record actual installed conditions and must be updated throughout construction, not reconstructed at the end of the project.

Progress reporting: percent complete by cost or by quantity installed; compare against the baseline schedule and flag variance early.

Professional practice: only perform work within trade certification and scope; report unsafe conditions; keep client and employer information confidential.

Hierarchy of controls, most to least effective: elimination, substitution, engineering controls, administrative controls, personal protective equipment.

Four classes of fall protection: guardrails, personal fall-arrest systems, safety nets, and travel-restraint systems; fall arrest requires a rescue plan before work starts.

Fall-arrest anchor strength: 22 kN (5,000 lbf) per worker for engineered anchors; free-fall distance kept under 1.8 m (6 ft) where practicable.

Respirable crystalline silica: workplace exposure limit commonly 0.025 mg/m3 (8-hour TWA) in Ontario; wet cutting and local exhaust ventilation are primary controls.

Confined-space entry requires a hazard assessment, entry permit, atmospheric testing (oxygen 19.5-23%), attendant, and rescue provisions before entry.

Hazardous energy control (lockout/tagout): isolate, lock, tag, verify zero energy by test, and confirm stored energy is released before work.

Noise: hearing protection required at 85 dBA Lex 8-hour; exposure limit 85 dBA in most Canadian jurisdictions; double protection above 105 dBA.

WHMIS 2016: pictograms, supplier labels, and safety data sheets with 16 sections; worker training required before handling a controlled product.

Incident reporting: report serious injuries and critical injuries to the regulator immediately; preserve the scene unless rescue or safety requires changes.

Erosion and sediment controls: silt fence, straw bale barriers, sediment traps, and check dams installed before grading; inspect after every rain event.

Silt fence placement: on the contour, keyed into the ground, with the fabric on the uphill side; not used in concentrated flow channels.

Spill response sequence: stop the source, contain with absorbent or berm, protect drains and watercourses, notify, and dispose of waste per regulation.

Designated substances and asbestos: suspect materials tested before disturbance; asbestos work follows jurisdiction-specific licensing and notification rules.

Waste segregation: separate clean fill, recyclable metals, wood, gypsum, and hazardous waste (paints, solvents, fuels) to meet diversion requirements.

Fuel storage: secondary containment sized to at least 110% of the largest container; drip trays under refuelling points.

Dust suppression: water carts or applied water on unpaved haul roads; visible dust from a site boundary is a common compliance trigger.

Protected trees: establish a tree protection zone at the drip line or per arborist plan; no storage, parking, or excavation inside it.

Benchmark (BM) is a fixed elevation reference; a temporary benchmark (TBM) is established on site and tied to the BM.

Differential levelling: HI = backsight reading + known elevation; unknown elevation = HI minus foresight reading. Arithmetic check: sum BS - sum FS = last RL - first RL.

3-4-5 method: a triangle with sides 3, 4, and 5 units has a 90-degree angle between the 3 and 4 sides; scale to 6-8-10 or 9-12-15 for larger layouts.

Building layout: set batter boards beyond excavation limits, stretch string lines, and transfer corners with a plumb bob or laser; confirm diagonals are equal for squareness.

Slope expressed as percent grade = (rise / run) x 100; a 2% slope drops 0.02 m per 1 m of horizontal run.

Station and offset notation: station is distance along a baseline, offset is perpendicular distance left or right; used to set utilities and structures.

Total station setup: occupy a known point, backsight a second known point, then check a third known point to verify angular closure before staking.

Site stripping: topsoil removed to a defined depth and stockpiled separately for later reuse in landscaping and restoration.

Trench definition: depth greater than width, and width at the bottom 2 m (6 ft) or less; deeper than 1.2 m (4 ft) requires a protective system in most Canadian jurisdictions.

Soil types: Type 1 (hard, stable), Type 2 (stiff, cohesive), Type 3 (soft, disturbed), Type 4 (running, submerged); each type sets maximum slope angles and shoring requirements.

Sloping for protection: Type 1 about 3/4:1, Type 2 about 1:1, Type 3 about 1.5:1, Type 4 requires engineering; verify against the local regulation table.

Spoil and equipment kept back at least 1 m (3 ft) from the trench edge; ladders within 7.5 m (25 ft) of travel for worker access and egress.

Locate buried utilities before digging by calling the provincial one-call service and hand exposing within the tolerance zone; never machine dig near marked lines.

Daily and post-rain inspection by a competent person: check for tension cracks, sloughing, water accumulation, and spoil loading at the crest.

Trench boxes: installed so the top is above grade and the bottom is within 0.6 m (2 ft) of the trench bottom; workers stay inside the box during hoisting.

Atmospheric testing before entry: oxygen 19.5-23%, combustible gas below 10% LEL, and toxic gases below exposure limits; continue monitoring while occupied.

Concrete mix ratio by volume for general work: 1 part cement, 2 parts sand, 3 parts coarse aggregate; water-cement ratio controls strength and durability.

Formwork design loads: concrete weight about 24 kN/m3 (150 lb/ft3), plus live load, impact, and lateral pressure from fresh concrete.

Formwork removal: sides of non-load-bearing forms after concrete is hard enough not to be damaged; soffits and props only after the specified strength is reached (commonly 70% of design strength for slabs).

Slump test measures workability; typical structural range 75-125 mm; test per CSA A23.2 on a sample from the middle of the load.

Curing: keep concrete moist and above 5 degrees C for at least 7 days (Type 1 cement) or per specification; cold weather requires insulation and temperature records.

Formwork ties and bracing: snap ties rated for the lateral pressure; vertical and diagonal bracing to resist wind and placement forces.

Control joints are sawn or formed to a depth of about 1/4 slab thickness to control random cracking; spacing typically 24-36 times slab thickness.

Concrete placement: free fall limited to about 1.5 m (5 ft) to prevent segregation; vibrate systematically without over-vibration.

Mortar types: M (high strength, 2500 psi), S (medium-high, 1800 psi), N (general purpose, 750 psi), O (low strength, 350 psi); S or N common for exterior load-bearing walls.

Standard modular brick: 90 mm x 57 mm x 190 mm face dimensions with 10 mm mortar joints; nominal module 200 mm x 67 mm x 200 mm.

Running bond: each course offset half a brick; common bond has header courses every fifth or sixth course; English bond alternates stretcher and header courses.

Wall ties: corrosion-resistant ties spaced at 600 mm horizontally and 400 mm vertically for cavity walls, with one tie per 0.25 m2 of wall area.

Flashing and weepholes: weepholes spaced at 800 mm (32 in) maximum and at 600 mm (24 in) near lintels; flashing lapped and terminated with a drip edge.

Lintel bearing: typically 100 mm (4 in) minimum bearing each side for masonry lintels; verify with the structural design.

Masonry grout: slump 200-275 mm for reinforced hollow block; consolidation by puddling or mechanical vibration to fill voids.

Scaffold for masonry: working platform width at least 500 mm (20 in), fully planked, with guardrails at 1 m and 2 m and toe boards.

Nominal to actual lumber: 2x4 is 38 x 89 mm, 2x6 is 38 x 140 mm, 2x10 is 38 x 235 mm; dressed dimensions govern spans and loads.

Floor joist spans are tabulated by species, grade, size, spacing, and live load; never overspan without checking the span table or engineer.

Bearing and notching: a notch in the top of a joist limited to 1/4 depth at the ends and 1/6 depth in the middle third; holes kept to the middle third of depth.

Stud spacing: 400 mm (16 in) or 600 mm (24 in) on centre; load-bearing walls require a double top plate and full bearing under headers.

Header sizing: opening width plus 75 mm (3 in) bearing each side; header depth increases with span and load; jack and king studs flank the opening.

Roof pitch = rise / run; a 4/12 pitch rises 4 units per 12 units of run, giving an angle of about 18.4 degrees.

Rafter length = run / cos(pitch angle); multiply the run by the pitch factor for the common rafter length.

Truss installation: follow the truss layout drawing, brace per the truss designer, and never cut or notch truss members without engineering approval.

Sheathing fastening: panel edges supported and nailed at 150 mm (6 in) on centre, field nails at 300 mm (12 in) on centre for subfloor, per the schedule.

Sling angle effect: tension = load / (number of legs x sin of the angle to horizontal); at 30 degrees, each leg carries the full load, at 60 degrees about 0.58 of the load.

Load centre of gravity must be below the hook for a stable lift; tag lines control rotation and are never wrapped around hands or body.

Rigging inspection: remove slings with broken wires, kinks, cuts, or missing tags; wire rope removal criteria include 10 randomly distributed broken wires in one lay.

Rated capacity of a sling is reduced by the splice, hardware, and configuration; never exceed the manufacturer's tag rating.

Crane hand signals: standardized signals used by a designated signaller; stop signal is one arm extended palm down, moving arm side to side.

Outrigger setup: fully extended on stable bearing pads; verify ground bearing capacity and keep clear of excavations and underground services.

Rigging hardware: shackles, hooks, and swivels rated with a proof load and marked; hooks with cracks or more than 10% throat opening deformation are removed.

Load weight estimate: steel 7850 kg/m3, concrete 2400 kg/m3, wood (softwood) about 500 kg/m3; volume times density gives mass.

Guards on circular saws return to cover the blade automatically; the riving knife is set within 5 mm of the blade and no higher than the blade top.

Abrasive wheels: ring test before mounting; match wheel speed rating to the tool; guard covers at least half the wheel and the tool has a dead-man switch.

Powder-actuated tools: operator certified, eye and hearing protection, and the tool never loaded until immediately before use; misfire held down for 30 seconds.

Compressors and air tools: hose whip checks at every connection; never exceed the tool's rated pressure; drain receiver tanks regularly.

Ladder setup: 4:1 rule, one unit of horizontal distance for every four units of vertical height; extend 1 m (3 ft) above the landing for access.

Scaffold inspection: check sills, base plates, plumb, bracing, planks, guardrails, and ties before each shift and after alteration or high wind.

Fuel-powered equipment: never refuel a hot engine or in an enclosed space; store fuel in approved containers away from ignition sources.

Lockout applies to maintenance: de-energize, isolate, lock, tag, and verify the equipment cannot start before removing guards or clearing jams.

Pre-demolition survey: identify hazardous materials (asbestos, lead paint, PCBs), structural load paths, and utilities; disconnect and cap services before demolition.

Demolition sequence generally works top-down and from the least to most stable elements; never undercut a wall or leave unsupported masonry above a work area.

Designated substance survey before renovation: test suspect materials for asbestos and lead; abatement by qualified workers with air monitoring before general demolition.

Lead paint removal from a building constructed before 1980 requires controls: containment, HEPA vacuum, wet methods, and personal exposure monitoring.

Chimney demolition: remove from the top down in sections; do not topple a chimney onto a structure, and brace it during removal.

Debris removal: chutes or covered openings for material above one storey; drop zones barricaded and controlled by a spotter.

Site cleanup: remove debris daily, keep walkways clear, and separate waste streams for recycling and disposal records.

Burning is prohibited on construction sites in most jurisdictions; debris is hauled to an approved disposal or recycling facility.

Contract documents hierarchy: agreement, general conditions, supplementary conditions, specifications, drawings, and addenda; the order of precedence is stated in the contract.

A request for information (RFI) documents a clarification; a change order is a written, signed modification to scope, price, or schedule; never proceed on verbal direction alone.

Shop drawings are contractor-prepared detail drawings submitted for design review; approval does not relieve the contractor of contract compliance.

Site diary entries: date, weather, crew and equipment on site, work performed, visitors, delays, deliveries, and instructions received, recorded the same day.

Field instruction and site instruction records: written confirmation of verbal directions issued within 24-48 hours to preserve claims.

As-built drawings record actual installed conditions and must be updated throughout construction, not reconstructed at the end of the project.

Progress reporting: percent complete by cost or by quantity installed; compare against the baseline schedule and flag variance early.

Professional practice: only perform work within trade certification and scope; report unsafe conditions; keep client and employer information confidential.