Job takeoff
Wet-room tanking takeoff
Liquid membrane, isolation layer and backer board for a room with no tray and no threshold.
A takeoff is the trade word for the shopping list a job produces — every material, and how much of each, worked out by its own cited calculator.
- 7Measurements in
- 3Trades out
Give the job once
Every figure on the right follows these, in the units you choose.
Been given a quote for this job?
Paste it into the wet-room tanking quote check: each line is read against these same calculators — what it leaves out, what it adds, and what to ask.
Check the quoteEvery trade, from those dimensions
then change a dimension, and each line shows what moved.
| Trade | Quantity | |
|---|---|---|
Wet Room Tanking and Waterproof Membrane CalculatorMembrane in two coats over the whole floor and the tanked walls, with tape round the floor's edge and up each internal corner plus 10% for laps, and a preformed collar at each pipe through the membrane; the drain's collar comes with the drain.
Why this quantity?
Resting on
Change any other figure on the Wet Room Tanking and Waterproof Membrane Calculator | 9 gal | |
Floor Crack Isolation Membrane Coverage CalculatorIsolation across the floor, under the tiling.
Why this quantity?
Resting on
Change any other figure on the Floor Crack Isolation Membrane Coverage Calculator | 1 roll | |
Tile Backer Board CalculatorRated backer across the whole floor and the tanked walls, less the footprint of any pre-formed former, which is laid in place of the backer.
Why this quantity?
Resting on
The cutting waste: the calculator's working figure, a trade convention. | 20 boards | |
Wet Room Tanking and Waterproof Membrane CalculatorMembrane in two coats over the whole floor and the tanked walls, with tape round the floor's edge and up each internal corner plus 10% for laps, and a preformed collar at each pipe through the membrane; the drain's collar comes with the drain.
Why this quantity? | 34 litres | |
Floor Crack Isolation Membrane Coverage CalculatorIsolation across the floor, under the tiling.
Why this quantity? | 1 roll | |
Tile Backer Board CalculatorRated backer across the whole floor and the tanked walls, less the footprint of any pre-formed former, which is laid in place of the backer.
Why this quantity? | 21 boards |
Estimates, not a quote. Each row gives its base, the allowance on top, the adjusted figure and what to order; change an allowance on the row, or open its reasoning to see every figure it rests on. A trade's own page carries what it does not cover — open the one you are about to order against.
Labour and programme
Person-hours for the rows going in, from trade rules of thumb: a range for each piece of work, never a price.
- Wet Room Tanking and Waterproof Membrane3.3 h (1.7–6.6)
- Tile Backer Board5.0 h (2.5–10.0)
About 8.3 person-hours in the rows that carry them, between 4.2 and 17.
Trade by trade
- Waterproofing operative1 waterproofing operativehalf a day
- Tiler1 tilerhalf a day
About 1 day, one trade after another at eight hours a day. Left out: drying and curing, deliveries, inspections, trades overlapping.
1 row carries no hours of its own
- Floor Crack Isolation Membrane Coverage: no rate for its work here yet
Labour and programme
Person-hours for the rows going in, from trade rules of thumb: a range for each piece of work, never a price.
- Wet Room Tanking and Waterproof Membrane3.4 h (1.7–6.8)
- Tile Backer Board5.1 h (2.5–10)
About 8.5 person-hours in the rows that carry them, between 4.3 and 17.
Trade by trade
- Waterproofing operative1 waterproofing operativehalf a day
- Tiler1 tilerhalf a day
About 1 day, one trade after another at eight hours a day. Left out: drying and curing, deliveries, inspections, trades overlapping.
1 row carries no hours of its own
- Floor Crack Isolation Membrane Coverage: no rate for its work here yet
Setups you have saved
The build-up, the dimensions and any allowance you changed — kept on this device, and reusable on any job. Your prices are not copied in: they stay in your price book, so a setup never holds a stale one.
How far does a budget go?
At your own prices, with this build-up unchanged.
About this job
A wet room is defined by what it does not have. There is no tray to contain the water and no threshold to stop it, so the floor falls to a drain and the waterproofing is the only thing between the shower and the ceiling below. That makes the tanked area the whole floor and a generous height up every wall, rather than the shower zone — and it is why this takeoff asks for the wall run separately instead of assuming a shower's three sides.
Failures in wet rooms are almost never in the middle of a surface. They are at the junctions: floor to wall, wall to wall, and around the drain and any pipe that comes through. Tape and reinforcement at those details are what the system depends on and are not a function of area at all, which is why the tanking row counts them apart from the membrane: tape by the length of the floor's edge and the corners plus 10% for laps, and a preformed collar for each pipe that comes through. The drain's own collar is part of the drain and is left out with it.
The fall is the other thing an area cannot give you. A wet-room floor needs a consistent gradient to the drain across its whole extent, and building it into the deck — rather than making it up in the screed or the adhesive — is what separates a wet room that drains from one that puddles.
How each line reads
- Base
- What the calculator gives for these dimensions, before anything is added.
- Allowance
- Cutting waste, a lap or spare stock — named, with where it comes from, and changeable on the row.
- Adjusted
- The base with its allowance on top.
- Order
- What to buy: the adjusted figure in whole boards, bags, rolls or lengths.
The order this happens in
Quantities do not tell you the sequence, and on this job the sequence is where the money goes wrong.
- Set the drain position and build the fall into the floor deck, not into the tiling.
- Board the whole floor and the wet walls in a rated backer, with sealed joints.
- Prime everything the membrane will touch, and let the primer flash off.
- Tape the floor-to-wall junction, the internal angles and the drain collar first.
- Apply the membrane in the stated number of coats, at the stated wet film thickness.
- Flood-test before tiling. This is the last moment a failure is cheap.
What this takeoff does not cover
- The drain, its collar and the connection to the waste.
- Preformed corner pieces, where the system uses them at the corners in place of tape.
- The floor's fall and whatever forms it: a former, a graded deck or a screed.
- Tiling, adhesive and grout over the membrane.
- Primer, which absorbent substrates need and cement backer board often does not; apply the maker's rate to the tanked area in the tanking row's breakdown.
- Whether the structure below tolerates a wet room at all — a timber floor with no access beneath is a different risk from a slab.
Quote check
Been given a quote for this job?
Paste it into the wet-room tanking quote check. Every line of it is read against these same calculators and your measurements. Quantities only, never prices.
What it leaves out
Every line this takeoff has that nothing on the quote reads as.
What it adds
Labour, removal, hire, fees — each named for what it is.
What to ask
One list of questions, ready to copy. Never a verdict.
More takeoffs
Other job takeoffs
Kitchen refit
16 tradesStrip out a kitchen and fit a new one: base and wall units by standard width, the worktop (countertop) in stock lengths or as a template area, plinth (toe kick) and cornice, a tiled splashback, the new floor and the decoration, with the plumbing, electrical and gas work listed and never certified.
Run this takeoffBathroom remodel
4 tradesFloor tiling, backer board, adhesive and the extract fan's airflow for a full bathroom strip-out and refit, with the bath or tray, the tanking, the wall tiling, the sanitaryware and the services listed as work and never certified.
Run this takeoffShower enclosure
4 tradesTanking, backer board, tile and adhesive for the walls and tray area of a shower.
Run this takeoff
Frequently asked questions
- What does the wet-room tanking takeoff give for a typical job?
- Opened at Floor length 2.5 m · Floor width 2 m · Tanked wall run 6 m · Tanked height 2 m · Internal corners in the tanked zone 2 · Pipe penetrations through the membrane 3 · Pre-formed former footprint 0 m², it orders: Wet Room Tanking and Waterproof Membrane, 34 litres; Floor Crack Isolation Membrane Coverage, 1 roll; Tile Backer Board, 21 boards. Opened at Floor length 8 ft · Floor width 6.5 ft · Tanked wall run 19.5 ft · Tanked height 6.5 ft · Internal corners in the tanked zone 2 · Pipe penetrations through the membrane 3 · Pre-formed former footprint 0 sq ft: Wet Room Tanking and Waterproof Membrane, 9 gal; Floor Crack Isolation Membrane Coverage, 1 roll; Tile Backer Board, 20 boards. Every figure follows the dimensions you give it.
- Which calculators does the wet-room tanking takeoff run?
- 3 calculators, one to a line: Wet Room Tanking and Waterproof Membrane Calculator, Floor Crack Isolation Membrane Coverage Calculator, Tile Backer Board Calculator. Each has a page of its own with its formula and its sources; the takeoff runs them all on one set of dimensions.
- What does the wet-room tanking takeoff leave out?
- 6 things, each named on this page: The drain, its collar and the connection to the waste; Preformed corner pieces, where the system uses them at the corners in place of tape; The floor's fall and whatever forms it; Tiling, adhesive and grout over the membrane; Primer, which absorbent substrates need and cement backer board often does not; apply the maker's rate to the tanked area in the tanking row's breakdown; Whether the structure below tolerates a wet room at all.
- Can I check a quote for this job against the takeoff?
- Yes. The wet-room tanking quote check reads a quote's lines against these same calculators and your measurements, and reports what it leaves out, what it adds and what to ask. It reads quantities, never prices.