Estimating guides
Plain-English guides to measuring, estimating and pricing work, written for South African builders and tradespeople with the right units, terms and rules.
Estimating concrete in South Africa: bags, cubes and MPa
Work out the volume, add sensible waste, then turn it into 50 kg bags of cement and cubes of sand and stone, or a ready-mix order in the strength on your plans.
4 min readConcrete & MasonryConcrete mixes by the wheelbarrow
How South African builders batch concrete, mortar, plaster and screed by the bag and the barrow, with the Concrete Society’s figures for each mix.
3 min readConcrete & MasonryBagged cement or ready-mix: where the break-even sits
How to compare mixing on site with ordering ready-mix for your job, using your own supplier prices, and what else besides price should decide it.
4 min readConcrete & MasonryStrip foundations under SANS 10400-H
The widths, thickness and concrete SANS 10400-H asks for under house walls, how to take off the trenches, concrete and foundation brickwork, and when you need an engineer.
3 min readConcrete & MasonryFloor slabs, DPM and mesh
What SANS 10400-J asks of a concrete floor slab on the ground: thickness, membrane, panel sizes and fill, and when the slab needs mesh or an engineer.
4 min readConcrete & MasonryDamp-proofing: DPC, DPM and rising damp
Where the damp-proof course and membrane go under SANS 10400-K and -J, the details that keep them working, and why plaster over the DPC is the most common cause of rising damp.
3 min readConcrete & MasonryHow many bricks do I need?
Bricks and blocks per square metre for South African sizes, how to measure walls and openings, and how much cement and sand the mortar takes.
3 min readConcrete & MasonryNFP, NFX, FBS, FBX: choosing the right brick
What the South African clay brick classes in SANS 227 mean, where each one belongs, and what the E-number on an engineering brick tells you.
3 min readWalls & FinishesMortar and plaster mixes
Class I and Class II mortar, internal and external plaster, common or masonry cement: the Concrete Society’s quantities and how to batch them on site.
3 min readConcrete & MasonryBuilding a boundary wall
How high a free-standing brick wall may be under SANS 10400-K, when it needs piers and how far apart, and how to take off the bricks, foundation and mortar.
3 min readConcrete & MasonryPaving a driveway
Ordering pavers, kerbs, bedding and jointing sand, preparing the base and laying the pavers, following the Concrete Manufacturers Association’s step-by-step guide.
3 min readConcrete & MasonryRetaining walls with Terraforce and Löffelstein
How concrete retaining blocks work, the height limits in Terraforce’s and Infraset’s published data, how to count blocks, and when you need plans and an engineer.
3 min readLandscaping & EarthworksSand, stone, topsoil and excavation: cubes, skips and loads
How South African suppliers sell sand, stone and topsoil, which sand goes where, how to work out cubes, and how many skips a dig fills.
3 min readCarpentry & FramingRoof trusses and SA pine grades
What SANS 10400-L allows for a simple timber truss roof: spacing by roof covering, pitch limits, member sizes and grades, treatment, and when trusses must be designed.
3 min readRoofingEstimating concrete tiles, IBR and corrugated roofs
How to count concrete roof tiles and battens, IBR sheets, purlins and screws, with the makers’ published figures and the SANS 10400-L slope limits.
4 min readRoofingRoof pitch rules and when you need a membrane
The minimum pitches SANS 10400-L sets for tiles, slates and sheeting, and the three situations where an undertile membrane is required.
3 min readRoofingGutters and downpipes
How to take off a PVC gutter system: lengths, outlets, brackets, joints and downpipes, with the installation rules in Marley’s South African guide.
3 min readWalls & FinishesCeilings: brandering, gypsum boards and finishes
How a brandered RhinoBoard ceiling is built and counted: brander size by truss spacing, brander centres by board and finish, board sizes and screw spacing, from Gyproc’s guide.
3 min readWalls & FinishesCeiling insulation under SANS 10400-XA
The roof R-values SANS 10400-XA asks for in each energy zone, how to choose an insulation product to meet them, and how to work out the quantity.
3 min readWalls & FinishesHow much paint do I need?
Work out the area, the coats and the litres, then the South African tin sizes to buy, with spread rates from Plascon’s published data.
3 min readFlooring & TileTile estimating: tiles, adhesive and grout
How many tiles, bags of adhesive and grout a floor or wall needs, with waste by layout and TAL’s published adhesive and grout figures.
3 min readStairs, Ramps & RailsStair and balustrade rules under SANS 10400-M
The rise, going, 2R + G, headroom, width, landing, balustrade and handrail rules for stairs in SANS 10400-M, with a worked staircase.
3 min readElectrical & LightingElectrical CoCs and voltage drop
Why every electrical installation needs a Certificate of Compliance, what SANS 10142-1 says about voltage drop, cable sizes and plug circuits, and how to check a long cable run.
3 min readPlumbing & WaterGeysers, PIRB CoCs and the 50% solar rule
Sizing a geyser for a household, what heating the water costs in kWh, the XA2 rule that half a new building’s hot water must come from solar or a heat pump, and the PIRB CoC.
3 min readElectrical & LightingSolar, inverters and batteries for load shedding
How to size an inverter and a lithium battery bank for load shedding: list the load, check the surge, work out the energy and the usable battery capacity.
3 min readPlumbing & WaterWater backup: JoJo tanks, rainwater and boreholes
How much water a roof collects, which JoJo tank holds it, and how to turn a borehole yield test into the flow and head a pump supplier needs.
3 min readPlumbing & WaterDrain falls and septic tanks under SANS 10400-P
Minimum drain size, the falls SANS 10400-P allows by drain load, and how to size a septic tank and french drain from the standard’s tables.
3 min readPricing & BusinessWaste factors by trade
How much extra to allow for cutting, breakage and spillage in each trade, the allowances BouWise uses by default, and where makers publish their own.
3 min readPricing & BusinessPlans, minor building work and council approval
When the National Building Regulations need approved plans, what counts as minor building work, what the plans must include, and the notices and inspections during building.
3 min readPricing & BusinessNHBRC registration and home enrolment
Why home builders register with the NHBRC, the rule that every new home is enrolled at least 15 days before building starts, and the warranty cover enrolment gives the owner.
3 min readPricing & BusinessVAT for contractors: 15%, the R2.3 million threshold and tax invoices
When a contractor must register for VAT, how to add and remove 15% VAT, and what a full or abridged tax invoice must show under SARS’s checklist.
3 min readPricing & BusinessWriting a quote and setting your day rate
How to build a day rate that covers wages, overheads and profit, cost a job from material lists and labour, add travel at the SARS rate, and write a quote clients understand.
3 min read