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Each calculator adds its lines to a single estimate — consolidated BOM, schedule and cash-flow included.

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Trade guides

The calculators give you a quantity. These explain the work around it — the order things happen in, the tolerances that matter, and the mistakes that only show up months later.

Each guide carries the relevant calculators inline, so you can work through the numbers where they come up rather than opening a second tab. The methodology pages cover the mathematics behind those calculators; these cover the site work.

A quantity is the easy half. Concrete is ordered by volume and fails by curing; a pavement is priced by tonnage and fails at the joint; an air conditioner is bought by capacity and fails by being too large for the house it was bought for. None of that is visible in the number, and none of it is arithmetic — which is why it lives here rather than on the calculator pages or in the methodology.

What each guide tries to be specific about: the order operations actually happen in, the tolerances that decide whether the next trade can work, the measurement that predicts whether the work lasts, and the failure that shows up a season later rather than on the day. Where a figure varies by jurisdiction, the guide says so and names what governs it instead of publishing a number that would be wrong somewhere.

These are written for people who already work in the trade, so they assume the vocabulary and skip the introductions. They are guidance rather than specification: local codes, the engineer of record and the manufacturer’s instructions govern wherever they differ.

Structure and carpentry11 guides

  • Carpentry

    Building a Timber Deck

    A carpenter's walk down the load path of a timber deck — footing, post, beam, joist, board — each member sized by what the one above hands down.

    6 sections · 6 linked calculators · last reviewed

  • Carpentry

    Building Stairs That Pass Inspection

    A one-millimetre layout error repeats once per riser, so control the whole flight from a single datum and prove the spread before the inspector arrives.

    9 sections · 5 linked calculators · last reviewed

  • Mass timber

    Building With CLT and Glulam

    Mass timber erection is finish work: every CLT panel and glulam beam you set is the ceiling below it, so damage is permanent.

    11 sections · 5 linked calculators · last reviewed

  • Carpentry

    Cutting and Setting Rafters

    A carpenter's field guide to rafter layout, treating every plumb, seat and cheek cut as one triangle solved from run and rise.

    6 sections · 5 linked calculators · last reviewed

  • Structure

    Designing a Roof for Snow

    Snow does not load a roof where it falls but where wind and slide pile it, so frame the drifts before the field.

    10 sections · 5 linked calculators · last reviewed

  • Carpentry

    Framing a Load-Bearing Wall

    A bearing wall read as a load path from the ground up: what the sole plate stands on, and how studs, headers and plates hand weight down.

    9 sections · 5 linked calculators · last reviewed

  • Structure

    Installing a Steel Beam

    A steel beam almost never fails in strength — it fails the ceiling underneath, so deflection limits and bearing movement govern the whole install.

    9 sections · 5 linked calculators · last reviewed

  • Structure

    Bolted and Welded Steel Connections

    A load-path field guide to steel joints: every bolt, weld, plate and stiffener a force must cross to leave one member and enter the next.

    11 sections · 4 linked calculators · last reviewed

  • Carpentry

    Timber Connections That Carry

    Timber members rarely break — their joints do, so this field guide sorts carpentry connections by the way each one actually gives way.

    9 sections · 5 linked calculators · last reviewed

  • Foundations

    Footings, Piers and Frost Depth

    Every footing answers to two independent depths — competent bearing and the frost line — and the deeper of the two governs the dig.

    8 sections · 6 linked calculators · last reviewed

  • Structure

    Setting Steel Columns and Baseplates

    How a steel column is set true at the top where it buckles and bedded solid at the bottom where it crushes, from anchor layout through final grout.

    7 sections · 5 linked calculators · last reviewed

Concrete and masonry8 guides

  • Concrete

    Building and Bracing Formwork

    Formwork pressure follows the rate you fill at, so the pour plan sizes the ties, walers and bracing long before a panel is cut.

    9 sections · 5 linked calculators · last reviewed

  • Concrete

    Curing Concrete in Heat and Cold

    Curing is a race between hydration and evaporation, and every measure on a concrete pour either slows one clock or speeds the other.

    7 sections · 4 linked calculators · last reviewed

  • Concrete

    Detailing Rebar: Laps, Hooks and Cover

    A concrete field guide to what actually develops a reinforcing bar on site — bond length, hooks, cover and the details that quietly shorten all three.

    7 sections · 5 linked calculators · last reviewed

  • Concrete

    Jointing Concrete Flatwork

    Flatwork concrete cracks whether you plan for it or not, so jointing is the trade of choosing the crack line before the slab does.

    7 sections · 4 linked calculators · last reviewed

  • Masonry

    Laying Brick and Block

    Every masonry wall is one course repeated: get the unit, its bed, its perpend and its bond right, and the rest is multiplication.

    8 sections · 5 linked calculators · last reviewed

  • Concrete

    Placing and Pumping Concrete

    A field guide to moving ready-mixed concrete from truck to formwork with its water-cement ratio, air content and workability still intact.

    10 sections · 5 linked calculators · last reviewed

  • Concrete

    The Master Guide to Pouring a Professional Concrete Slab

    A pour told in order, from subgrade compaction the week before to the joints, the cure, and the cracks that appear a month later.

    10 sections · 3 linked calculators · last reviewed

  • Wet trades

    Rendering and Plastering a Wall

    A coat-by-coat field guide to render and plaster: reading what the background drinks, and keeping every coat weaker and thinner than the one beneath it.

    8 sections · 6 linked calculators · last reviewed

Roof and envelope12 guides

  • Facade

    Installing a Curtain Wall

    The mullion carries and the glass rides: a facade install organised around the load path from glass to frame to bracket to slab edge.

    9 sections · 5 linked calculators · last reviewed

  • Roofing

    Installing a Standing Seam Metal Roof

    Standing seam panels expand and contract every single day, and every clip, seam and trim detail either allows that movement or fights it.

    10 sections · 5 linked calculators · last reviewed

  • Cladding

    Installing an EIFS Wall System

    An EIFS wall fails at its bond lines, not inside its materials, so build the laminate outward and protect every interface.

    9 sections · 5 linked calculators · last reviewed

  • Cladding

    Installing Fibre Cement Cladding

    Fibre cement will not forgive a flexed sheet, a blunt blade, a crushed nail head or a drifted reveal — a field guide built around those limits.

    9 sections · 5 linked calculators · last reviewed

  • Cladding

    Installing Siding and the Drainage Plane

    Siding is a screen, not a seal: build the wall outward so every drop that gets behind the cladding has a way back out.

    9 sections · 6 linked calculators · last reviewed

  • Openings

    Installing Windows and Exterior Doors

    Windows and exterior doors fail at the sill before they fail anywhere else, so build the pan first and work outward from it to the casing.

    10 sections · 4 linked calculators · last reviewed

  • Building envelope

    Insulating a Wall Without Thermal Bridges

    Framing is the hole in a wall's insulation: what interrupts the thermal layer on a job site, and what restores it.

    9 sections · 5 linked calculators · last reviewed

  • Building envelope

    Insulating an Attic

    Attic heat loss ranked biggest hole first: air leakage, bare gaps, depth, the hatch, ducts, then the eave perimeter.

    10 sections · 5 linked calculators · last reviewed

  • Roofing

    Low-Slope and Flat Roofing

    On a flat roof every failure has an address: find where the water stops, then price what it costs in build-up to move it.

    9 sections · 6 linked calculators · last reviewed

  • Roofing

    Shingling a Roof

    Shingling judged the way water judges it: every lap, nail and flashing traced from the ridge slot down to the gutter line.

    10 sections · 5 linked calculators · last reviewed

  • Rainwater

    Sizing Gutters and Downspouts

    A rainwater run carries only what its tightest point allows, so size the trough, the outlet drop and the leader against one storm.

    10 sections · 4 linked calculators · last reviewed

  • Building envelope

    Balancing Roof Ventilation

    Roof intake and exhaust form a single pressure loop — the failures all trace back to one side outrunning the other.

    11 sections · 4 linked calculators · last reviewed

Interiors and finishes10 guides

  • Interiors

    Taping and Finishing to a Level

    Levels 0 through 5 are a ladder of coats and scrutiny: what each rung costs, what light exposes, and where a specification should stop.

    9 sections · 4 linked calculators · last reviewed

  • Interiors

    Hanging a Suspended Ceiling

    A suspended ceiling is a grid borrowed from structure that never expected it — work upward from tile face to hanger wire to deck.

    7 sections · 5 linked calculators · last reviewed

  • Interiors

    Hanging Drywall

    Hanging drywall as a chain of decisions — board direction, joint placement, fastener depth — and what each one costs the finisher later.

    9 sections · 5 linked calculators · last reviewed

  • Interiors

    Installing a Raised Access Floor

    A raised access floor is governed by the single loaded caster that crosses it, not by the kilonewtons per square metre on the schedule.

    10 sections · 4 linked calculators · last reviewed

  • Flooring

    Floating Floor Installation

    A floating floor is one raft that changes size all year; every gap, break and transition you cut exists to let it move.

    10 sections · 4 linked calculators · last reviewed

  • Finishes

    Laying a Resinous Floor

    Resin floors fail at the slab, not the topcoat — read moisture, profile and contamination before any resin is opened.

    8 sections · 4 linked calculators · last reviewed

  • Flooring

    Laying Carpet and Carpet Tile

    Broadloom arrives at a fixed width, so seam placement — not room area — drives every carpet and carpet-tile decision on site.

    10 sections · 4 linked calculators · last reviewed

  • Tiling

    Setting Floor Tile

    Floor tile is set out before it is set: the first two lines you strike decide every cut, joint and threshold in the room.

    8 sections · 5 linked calculators · last reviewed

  • Finishes

    Marking Out Lines and Sports Courts

    A court is a geometry problem that ends in a spray gun: how to set out, prove and record the lines before any paint is mixed.

    9 sections · 5 linked calculators · last reviewed

  • Finishes

    Painting Interior Walls

    On interior work the substrate sets the numbers: porosity, adhesion and the old colour decide coverage, primer class and coat count.

    9 sections · 5 linked calculators · last reviewed

Site and groundwork14 guides

  • Hardscape

    Building a Retaining Wall

    A hardscape field guide organised around the two ways retaining walls fail: rotating about the toe, and sliding forward on the base.

    15 sections · 6 linked calculators · last reviewed

  • Stormwater

    Permeable Paving and Storage Below It

    A permeable pavement is a tank built out of gaps, and every layer from joint aperture to subgrade earns its keep by void ratio.

    9 sections · 5 linked calculators · last reviewed

  • Sitework

    Erosion and Sediment Control

    Every erosion and sediment control on a jobsite does one of two things: it slows water down, or it catches the soil that water is already carrying.

    10 sections · 5 linked calculators · last reviewed

  • Below grade

    Draining a Wet Basement

    Wet basements are a pressure problem: read the head, relieve it at the slab and footing, and pump only what the relief path actually delivers.

    8 sections · 6 linked calculators · last reviewed

  • Sitework

    Grading a Site for Drainage

    Trace every drop from the divide above the pad to the permitted outlet, and size the grade at each transition it crosses.

    8 sections · 5 linked calculators · last reviewed

  • Sitework

    Laying a Gravel Driveway

    Angular stone locks and rounded stone rolls — how to build a gravel drive layer by layer so it stays where you put it.

    8 sections · 5 linked calculators · last reviewed

  • Sitework

    Laying Out a Car Park

    The vehicle you cannot turn away sets aisle width, stall angle and stall count on a site lot - lay it out from the swept path outward.

    10 sections · 5 linked calculators · last reviewed

  • Hardscape

    Laying a Paver Patio or Drive

    A hardscape field guide organised around the load path: the compacted base is the real pavement, and the pavers are only its wearing course.

    8 sections · 6 linked calculators · last reviewed

  • Demolition

    Planning Demolition and Debris Removal

    Demolition estimates are drawn in solid volume but paid in loose volume, and the swell factor between them decides how many lorries you book.

    10 sections · 5 linked calculators · last reviewed

  • Landscaping

    Planning Irrigation and New Turf

    Matched precipitation rate governs every irrigation zone: group heads by output before layout, then set turf and run times to the rate you measured.

    9 sections · 5 linked calculators · last reviewed

  • Sitework

    Industrial Asphalt Pavement & Sitework Prep

    A layer-by-layer read of an industrial asphalt section, from subgrade bearing up to joint density, with traffic loading setting every depth.

    10 sections · 7 linked calculators · last reviewed

  • Below grade

    Sealing and Conditioning a Crawlspace

    Encapsulating a crawlspace is dew-point work: every liner, foam board and dehumidifier decision either moves a condensing surface out of trouble or leaves it there.

    10 sections · 4 linked calculators · last reviewed

  • Landscaping

    Setting a Fence That Stays Up

    A fence is a sail before it is a boundary — here is how wind load decides post depth, bay spacing and infill on a landscaping job.

    6 sections · 5 linked calculators · last reviewed

  • Excavation

    Trench Safety and Support

    Soil classification is the design input for every trench — it sets the batter, the bench and the shield, and it changes mid-dig more often than crews expect.

    11 sections · 5 linked calculators · last reviewed

Building services16 guides

  • HVAC

    Balanced Ventilation and Heat Recovery

    Air in equals air out: how to set, size, duct, prove and defend the ventilation balance on real HVAC jobs.

    9 sections · 5 linked calculators · last reviewed

  • HVAC

    Residential Thermal Load Calculation & Design Manual

    A component-by-component anatomy of the residential heating and cooling load, and what happens when it meets the equipment catalogue.

    12 sections · 4 linked calculators · last reviewed

  • HVAC

    Heat Pumps and the Line Set

    A heat pump performs at the capacity its refrigerant path allows, not the capacity stamped on the outdoor unit's nameplate.

    8 sections · 5 linked calculators · last reviewed

  • Electrical

    Installing Cable Tray and Containment

    Cable tray comes down to two numbers — how full the section is and how far apart it is held — and every field decision trades one against the other.

    9 sections · 4 linked calculators · last reviewed

  • Heating

    Installing Radiant Floor Heating

    A radiant floor gives up only what its surface temperature limit allows, and spacing, water temperature and finishes all follow from that cap.

    10 sections · 5 linked calculators · last reviewed

  • HVAC

    Laying Out Ductwork

    The blower table sets a fixed static pressure allowance, and every fitting, filter and flex bend draws on it until the run stops balancing.

    9 sections · 5 linked calculators · last reviewed

  • Renewables

    Planning a Rooftop Solar Array

    A rooftop array is sized by the calendar, not the roof: match monthly production against monthly load and design for the months that fall short.

    7 sections · 6 linked calculators · last reviewed

  • Plumbing

    Running Drain, Waste and Vent

    Every DWV rule on a plumbing job exists to protect one of two things: continuous fall to the sewer, or free air behind the flow.

    7 sections · 4 linked calculators · last reviewed

  • Water supply

    Private Well Supply and Pressure Tanks

    How drawdown volume and pump cycle rate govern every sizing, setting and commissioning decision on a private well water supply.

    7 sections · 4 linked calculators · last reviewed

  • Pools

    Pool Circulation and Water Balance

    Turnover time sets pump duty, filter area, pipe size, chemical demand and running cost — size it once, honestly, and the rest of the plantroom follows.

    11 sections · 6 linked calculators · last reviewed

  • Electrical

    Sizing a Branch Circuit

    Size a branch circuit the way it actually gets sized: from the appliance nameplate back to the panel, one constraint at a time.

    9 sections · 6 linked calculators · last reviewed

  • Site services

    Sizing a Septic Drain Field

    Every dimension of a septic drain field descends from one measured percolation rate — how to take it, defend it, and protect it on site.

    8 sections · 4 linked calculators · last reviewed

  • Electrical

    Sizing a Standby Generator

    A standby set is sized by the worst starting instant on the panel, not by the tidy sum of running watts.

    9 sections · 4 linked calculators · last reviewed

  • Plumbing

    Sizing Domestic Hot Water

    Domestic hot water systems are sized by the worst sixty minutes a building sees, not by the gallons it burns over a whole day.

    7 sections · 4 linked calculators · last reviewed

  • Gas

    Sizing Gas Piping

    Sizing a gas system means walking the one route to the most distant appliance and spending its pressure allowance leg by leg.

    9 sections · 4 linked calculators · last reviewed

  • HVAC

    Venting a Commercial Kitchen Hood

    A commercial hood captures only what the replacement air allows, so size the make-up air, then the exhaust, duct and fan around it.

    9 sections · 5 linked calculators · last reviewed

Safety and compliance5 guides

  • Passive fire protection

    Building a Rated Shaftwall

    Shaftwall is the one rated assembly built entirely blind — every panel, stud and screw has to land from the corridor side alone.

    9 sections · 5 linked calculators · last reviewed

  • Accessibility

    Building an Accessible Ramp

    A ramp is one fixed vertical rise divided among runs, landings and handrails - spend that slope allowance before the first form board goes down.

    8 sections · 4 linked calculators · last reviewed

  • Passive fire protection

    Firestopping Penetrations

    Every penetration is a defeat of an assembly that was tested whole — how to name what was breached and install the listed system that puts it back.

    9 sections · 4 linked calculators · last reviewed

  • Lifting

    Planning a Crane Lift

    Capacity comes off a load chart written for a level test pad, and the ground under the outriggers has to be built to match it.

    8 sections · 5 linked calculators · last reviewed

  • Site safety

    Edge Protection and Fall Distance

    Fall clearance is a budget — free fall, absorber deployment, harness stretch, anchor movement and margin all spend it before the worker stops.

    10 sections · 5 linked calculators · last reviewed

Specialist trades2 guides

  • Fixings

    Anchoring Into Concrete and Masonry

    Every concrete anchor drags a cone of substrate with it — edge distance, spacing and embedment are all arguments about that cone.

    9 sections · 4 linked calculators · last reviewed

  • Acoustics

    Isolating Sound Through a Partition

    A path-by-path hunt for flanking on a separating wall, from the perimeter bead to the plenum, before anyone argues about board.

    9 sections · 5 linked calculators · last reviewed