Why Waterproofing Quotes Fall Apart - And How to Fix It Early

The Common Scenario

You're standing on-site, ready to start a job you priced weeks ago. But now, nothing lines up. The area looks bigger, the detailing’s more complex, and you realise you missed a few critical elements in your quote — maybe a tricky internal gutter, extra prep work, or waste factors for membrane overlap.

You priced to win, but now you're working thin.

This happens more often than most tradies admit — quoting with best guesses, quick measurements, or trusting the builder’s numbers. By the time you're installing, you’re spending more time fixing the quote than waterproofing.

The QS Insight

Most waterproofers lose money before they even get to site. Why? Because the quoting stage is rushed or done without full plan analysis. As Quantity Surveyors, we constantly see quotes fall short on:

• Missed plan details (like membrane termination, split areas)

• Underestimated material volumes due to overlaps or wastage

• Labour miscalculation from not spotting site challenges early

It’s not about being “wrong.” It’s about being unprepared.

Small misreads in the takeoff stage can compound into hundreds or thousands lost on materials, labour blowouts, or price disputes.

A Simple Tip

Do a scoped takeoff before you quote.

1. Get the actual plans — not just rough measurements or verbal specs.

2. Use a digital tool like Bluebeam, CostX or 3D Takeoff (or work with someone who does) to mark out each area and layer.

3. Scope and tag tricky areas — corners, flashings, posts, step downs.

4. Create a basic summary sheet that shows sqm, wastage %, detailing notes.

Even a 30-minute focused takeoff can prevent thousands lost — and it gives you confidence when presenting or defending your quote.

Stop Guessing. Start Quoting like a Pro.

Talk to us if you need help scoping your next job before sending the price.