7 questions to ask a waterproofing contractor in Durbanville

In a niche full of cowboys, the questions you ask before signing a quote are worth more than the quote itself. These are the seven that, in our experience, separate a 10-year waterproofing job from a 3-year one. Ask all seven of every contractor that quotes you. Their answers — and how comfortable they are answering — will tell you everything.

1. Are you a manufacturer-approved applicator? Show me the certificate.

Manufacturer-approved status is the single biggest predictor of a real warranty. Index, Derbigum, Sika, Plascon and Earthcote each train and certify applicators on their specific systems. Without it, the manufacturer’s product warranty is usually void — which means if the membrane fails in year four, you’ll be told to chase the contractor (who’s probably moved on or shut down). With it, the manufacturer comes back to inspect and replace.

If a contractor says “yes”, ask to see the certificate. It should have their name, the brand, the system, and an expiry date. No certificate? Move on.

2. What’s your workmanship guarantee, and is it written?

The Durbanville waterproofing market’s niche-standard is 10 years. Anything shorter is below market. Anything offered as a verbal handshake instead of a written certificate isn’t worth the air it’s spoken in. The written certificate should specify:

• The exact area covered (in m²) and the membrane spec
• What’s included (repair of failed seams, blisters, leaks)
• What’s excluded (damage from third-party trades, structural movement)
• The contractor’s registered company name and contact details
• The transferability clause if you sell the home

3. Will you do a free on-site inspection before quoting?

Real specialists insist on it. The reason: a real diagnosis matters more than a guess. They’ll run a moisture meter on the affected walls, check the membrane for blisters and alligatoring, look at parapet flashings, scan with a thermal camera if there’s an active leak, and possibly do a water-tracer dye test.

If a contractor quotes blind from a phone description, the cost overruns will surface mid-job — and you’ll be the one paying.

4. What system will you use, and why does it suit my roof?

The contractor should be able to answer this in plain English. “Your roof has minor cracking but the substrate is sound, so we’d use a Sikalastic 1K polyurethane to bridge the cracks and give you 15+ years” is a real answer. “The usual stuff” isn’t.

You’re testing whether they’ve diagnosed your roof or whether they sell one product to every customer. The latter is a red flag — different roofs need different systems.

5. Who actually does the work — your team or subcontractors?

Many Durbanville “contractors” are sales fronts that subcontract to whoever’s available that week. The quality varies job-to-job. Direct-employed teams produce more consistent work because the same supervisor is on every job.

Either model can work — but you should know which you’re getting. Ask: “Will the same team that quoted come back to do the install?” The answer should be yes.

6. What’s the surface prep budget?

Surface prep is where corner-cutting hides. The contractor should describe specifically:

• Pressure-cleaning method and pressure (1500–2500 PSI for most roofs)
• Crack repair using which product (epoxy mortar, polyurethane sealant, etc)
• Removal of old failed coatings
• Primer brand and coverage rate

If a quote treats prep as a single line item with no detail, the contractor is planning to skip whatever they decide is unnecessary on the day. Real prep accounts for 20–40% of the labour cost on a typical roof job.

7. Are you registered with BIBC and fully insured?

BIBC (Building Industry Bargaining Council) registration confirms the contractor is a legitimate building-industry employer paying their workers minimum wage and contributing to industry-standard pension and medical funds. Full public liability insurance (R5–10 million minimum) covers you if their work damages other parts of your home.

Both are easy to verify. Ask for the registration number and insurance certificate. Reputable contractors hand them over without hesitation.

Where to find Durbanville waterproofers who pass all seven

Every contractor listed on Waterproofing Durbanville has been vetted against these criteria. We verify Google Business Profile, manufacturer-approved applicator status, written 10-year guarantee, free inspection commitment, BIBC registration and active insurance before adding a listing. Browse vetted Durbanville waterproofing specialists or submit a free quote request and up to three of them will contact you within 24 hours.