Red Seal CCW flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Hierarchy of controls

Ranking of hazard controls from most to least effective: elimination, substitution, engineering controls, administrative controls, then personal protective equipment as the last line of defence.

Fall-arrest anchor strength

An engineered anchor point for personal fall arrest must resist about 22 kN (5,000 lbf) per worker attached, and a rescue plan must exist before work begins.

Confined space entry conditions

Before entry: hazard assessment, entry permit, atmospheric test showing oxygen between 19.5 and 23 percent, attendant outside, and rescue provisions in place.

Silt fence placement rule

Install on the contour with fabric on the uphill side and the bottom keyed into soil; use only for sheet flow, never in concentrated channels or streams.

Fuel storage containment

Secondary containment around fuel containers must hold at least 110 percent of the largest container volume, with drip trays under refuelling connections.

Spill response sequence

Stop the source, contain the spill with absorbent or berms, protect drains and watercourses, notify the required parties, then dispose of contaminated material per regulation.

Height of instrument formula

HI equals the known elevation plus the backsight reading; an unknown elevation equals HI minus the foresight reading taken on that point.

3-4-5 square method

A triangle with sides in ratio 3:4:5 has a 90-degree angle between the short sides; scale up to 6-8-10 for larger building layouts.

Percent grade formula

Percent grade equals rise divided by run, multiplied by 100. A 2 percent slope drops 0.02 metres for every 1 metre of horizontal distance.

Trench protective system trigger

A trench deeper than 1.2 metres (4 feet) generally requires a protective system such as sloping, shoring, or a trench box under Canadian occupational health and safety rules.

Spoil pile setback

Excavated spoil, materials, and equipment must be kept at least 1 metre (3 feet) back from the trench edge to reduce surcharge loading and collapse risk.

Formwork removal strength

Non-load-bearing side forms may be removed once concrete resists damage; soffit props stay until concrete reaches the specified strength, often 70 percent of design strength.

Concrete slump test purpose

The slump test measures fresh concrete workability and consistency; structural concrete commonly falls in a 75 to 125 millimetre slump range.

Mortar type selection

Type M is highest strength, S medium-high, N general purpose, and O low strength; Type S or N is typical for exterior load-bearing masonry walls.

Weephole spacing

Weepholes in a masonry veneer are spaced no more than 800 millimetres apart, reduced to 600 millimetres near lintels, to drain the cavity.

Nominal versus actual lumber

A nominal 2x4 measures 38 by 89 millimetres dressed; a 2x6 is 38 by 140 millimetres. Span tables use dressed dimensions, not nominal names.

Joist notching limits

Notches in the top of a floor joist are limited to one quarter of depth at the ends and one sixth of depth in the middle third of the span.

Sling leg tension formula

Tension per leg equals load divided by the number of legs times the sine of the angle to horizontal; flatter angles dramatically increase leg tension.

Rigging hook rejection

Remove hooks showing cracks, excessive wear, or throat opening deformation greater than 10 percent; never exceed the rated capacity marked on the tag.

Crane stop hand signal

The stop signal is one arm extended horizontally with palm down, moved side to side; only a designated signaller should direct the crane operator.

Ladder 4-to-1 rule

Set the ladder base one unit out for every four units of working height, and extend the top at least 1 metre (3 feet) above the landing surface.

Circular saw riving knife

The riving knife sits within 5 millimetres of the blade and no higher than the blade top, and the retracting guard must cover the blade automatically.

Abrasive wheel ring test

Tap a clean wheel lightly and listen for a clear ring; a dull thud indicates a crack. Match the wheel speed rating to the tool before mounting.

Pre-demolition hazard survey

Before demolition, identify asbestos, lead paint, PCBs, structural load paths, and utilities; disconnect and cap services and complete abatement before general demolition.

Demolition sequence principle

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

Change order versus RFI

A request for information seeks clarification and does not change the contract; a change order is a signed written modification to scope, price, or schedule.

Site diary content

Record date, weather, crew and equipment on site, work performed, deliveries, visitors, delays, and instructions received, entered the same day as events occur.

As-built drawing purpose

As-built drawings record actual installed conditions and must be updated continuously during construction, not reconstructed after project completion.

WHMIS 2016 information elements

Controlled products carry pictograms, supplier labels, and a 16-section safety data sheet; workers need training before handling any controlled product.

Trench box installation limits

A trench box top sits above grade and its bottom within 0.6 metres (2 feet) of the trench bottom; workers stay inside while the box is moved.

Roof pitch calculation

Pitch is rise over run; a 4/12 roof rises 4 units for every 12 horizontal units, an angle of about 18.4 degrees, and rafter length equals run divided by cosine of that angle.

Curing temperature and duration

Concrete should stay moist and above 5 degrees Celsius for at least 7 days with Type 1 cement, or per specification, with cold-weather insulation and temperature records.