If you've ever had a tender fall apart because the waterproofing numbers were off, you know how much a few missed square metres can cost. Our estimators walk through every wet area, balcony, podium and basement in the drawing set and measure it properly against AS 3740:2021 and AS 4654, so the BOQ you send out actually holds up.

Introduction to waterproofing estimation

Waterproofing doesn't get talked about much until it fails — and then it's usually the trade everyone's pointing fingers at. It's the membrane system standing between water and your floors, walls and structural slabs, whether that's a wet area, a balcony, a roof, a podium, a basement, a retaining wall or a planter box. It's also one of the most common sources of defect claims and insurance headaches in Australian construction, which is exactly why getting the spec and the installation right matters on every job, big or small.

Getting the numbers right at tender stage matters just as much as getting the install right on site. A proper waterproofing takeoff takes the architectural and hydraulic drawings and turns them into a real Bill of Quantities — membrane area, primer, reinforcement, protection board, sealants — all measured separately by location and checked against the relevant Standards. That's what we do: fast, accurate, standards-compliant takeoffs built for builders, subcontractors and project managers who need numbers they can actually tender, procure and control costs against.

Why accurate estimation matters

The waterproofing scope includes a lot of detailed requirements and needs careful review in the details. A small error in an upstand height or a junction length doesn't stay small — it compounds across the whole job. Getting the takeoff right protects your business at every stage:

• Tender accuracy — you're pricing off real measured quantities, not a gut-feel allowance
• Material procurement — order the right volumes of membrane, primer and reinforcement, and skip the on-site delays that come from running short
• Labour planning — put licensed waterproofing crews on site against actual area and linear-metre figures, not guesswork
• Reduced wastage — stop over-ordering membrane and protection board systems that aren't cheap to begin with
• Better profitability — protect your margin by pricing the whole scope, junctions and penetrations included, not just the easy bits
• Cost control — track variations against an itemised BOQ instead of arguing over a lump-sum allowance
• Fewer disputes — when the original scope was measured properly, there's a lot less to argue about later

Scope of work

Our waterproofing takeoffs generally cover the full range of internal and external wet areas and structures, including:

• Wet areas — bathrooms, showers, laundries and ensuites
• Balconies and external porches
• Roofs and roof terraces
• Podiums and podium decks
• Basements and below-ground structures
• Retaining walls
• Planter boxes and above-ground planters

What we measure

Every BOQ we put together separates quantities out by system and location, so you can price and order with confidence rather than crossing your fingers. That includes:

• Floor waterproofing area (m²), including set-down allowances
• Wall waterproofing area (m²), measured to the correct upstand height for each location
• Bond breakers and movement joints
• Fillets and cant strips at wall-to-floor junctions
• Primer coverage, matched to the substrate type
• Protection board area, for below-membrane and external applications
• Sealants, including movement-joint silicone at junctions
• Reinforcing tape and fleece at corners, penetrations and drain flanges

Our quantity takeoff process

We run the same process on every job so the BOQ is accurate and easy for you to check against the drawings:

• Review the architectural and hydraulic drawings
• Go through the specifications and manufacturer data sheets
• Map out the full waterproofing trade scope
• Measure quantities straight off the drawing set
• Split quantities out by location — wet areas, balconies, podiums, basements, planters, and so on
• Apply the relevant Australian Standards to each location and system
• Put together a detailed Bill of Quantities
• Quality-check everything against the drawings and specs
• Hand over the finished takeoff in Excel and PDF

Australian Standards we work to

Every takeoff we prepare is referenced against the current Australian Standards and the National Construction Code, including:

Standard	Scope
AS 3740:2021	Waterproofing of domestic wet areas — membranes, DFT, wall heights, floor falls and testing
AS 4654.1:2012	Design of waterproofing membranes for external, above-ground use (balconies, podiums, roofs)
AS 4654.2:2012	Installation requirements for external waterproofing membranes
AS 3600:2018	Concrete structures — crack control and cover requirements affecting waterproofing design
AS 2870:2011	Residential slabs and footings — moisture barriers and dampproofing under slabs
NCC Volume One & Two	National Construction Code — performance and deemed-to-satisfy provisions referencing AS 3740

What's included in our BOQ

Item	Included
Material Quantities	Yes
Labour Quantities	Yes
Area Measurements (m²)	Yes
Linear Measurements (lm)	Yes
Waste Allowance	Yes
BOQ in Excel Format	Yes
PDF Summary Report	Yes
Marked-Up Drawings	Yes

Industries we serve

• Residential
• Commercial
• Industrial
• Education
• Healthcare
• Retail
• High-rise
• Government
• Infrastructure

Software we use

• Bluebeam
• PlanSwift
• AutoCAD
• Excel

Why choose us

• Estimators who actually know waterproofing, not generalists
• Takeoffs prepared to current Australian Standards
• Fast turnaround when you're up against a tender deadline
• Competitive, transparent pricing
• A detailed, location-by-location BOQ, not a lump sum
• Proper quality assurance on every takeoff, every time
• Tender support for builders and subcontractors
• Real experience across Australian residential, commercial and infrastructure work

Frequently asked questions

How is waterproofing measured?

We measure floor and wall area in square metres, plus linear-metre quantities for reinforcing tape, cant strips, bond breakers and upstands — all split out by location and checked against AS 3740:2021 and AS 4654.

Do you measure walls separately?

Yes. Wall waterproofing is measured separately from the floor, at whatever upstand height applies to that location — for example 1800mm in a shower, or 25mm above a bath rim.

Is primer included?

Yes, every time. Primer coverage is built into the BOQ and matched to the substrate and membrane system specified for that location.

Are sealants included?

Yes. Movement-joint sealants and other ancillary sealants get their own line items in the BOQ so they're easy to price and order.

Can you estimate remedial waterproofing?

Yes — new-build or remedial, we handle both, including defect rectification and re-membrane scopes.

Get started

Need an accurate waterproofing quantity takeoff for your next project? Get in touch with our estimating team for a detailed BOQ prepared to Australian Standards, or call us on 0448 504 380.