Your project guide

What to expect during waterproofing works

Your building is about to undergo waterproofing remediation. Your first thought might be months of noise, restricted access, and a building site where your home used to be. The reality is more controlled than that — but only if your contractor stages it properly.

This page explains the full process — what happens at each stage, what residents will experience, and what your committee should expect from mobilisation through to handover. Written so you can forward it to owners before works begin.

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The Process

How waterproofing works — stage by stage

A waterproofing remediation project on an occupied strata building follows a predictable sequence. Here’s what happens from the day your committee approves the work through to handover.

1

Pre-start and resident notification

Before any tools hit site, your strata manager receives a pre-start pack — project timeline, contact details for the site supervisor, and a resident notification letter. This goes to every affected unit owner and tenant at least two weeks before mobilisation. The letter explains what’s happening, when, and who to contact if there’s an issue.

2

Site setup and protection

Scaffolding or edge protection goes up. Common areas and access paths are protected with hoarding, drop sheets, and signage. If balconies are being waterproofed, furniture is either relocated by residents beforehand or moved and protected by the crew. The building stays operational — lifts, fire stairs, and main entries remain accessible throughout.

3

Strip-back and investigation

Tiles, screed, and the existing failed membrane are removed back to the structural substrate. This is the noisiest phase — typically 2–3 days per balcony. Once stripped, the substrate is inspected for cracks, falls, and drainage issues. Any structural defects found at this stage are documented and reported to the engineer before proceeding.

4

Substrate repair and preparation

Cracks are chased out and repaired. Falls are corrected so water drains to the outlet — not pools against the door threshold. Drainage components are replaced if needed. The substrate must be structurally sound and correctly graded before any membrane goes down. This step is where most failed waterproofing jobs cut corners.

5

New membrane installation

A sheet membrane system is installed to the engineer’s specification — typically a torch-on or peel-and-stick system compliant with AS 4654.2. Critical details: upturns at walls (minimum 150mm above finished floor level), sealed penetrations at every pipe and drain, and lapped joints with no gaps. The membrane is flood-tested before tiling to confirm it’s watertight.

6

Tiling, finishing, and handover

Once the membrane passes flood testing, new screed and tiles are installed. Sealant joints are completed at all wall-to-floor junctions. The balcony or wet area is handed back to the resident with a QA checklist, photos of the membrane before it was covered, and a written warranty. Your strata manager receives the full compliance documentation pack.

Living Through Works

What this means for residents

Waterproofing works on an occupied building are disruptive — there’s no way around that. But disruption can be managed, staged, and communicated so residents know exactly what’s coming and when.

1

Access to your balcony

Each balcony is out of action for 3–4 weeks during active works (strip-back, repair, membrane, tiling). We stage balconies in groups — typically 2–4 at a time — so most residents retain access until their turn. You’ll get at least two weeks’ notice before your balcony is scheduled.

2

Noise and working hours

The loudest phase is demolition (tile and screed removal) — typically 2–3 days per balcony. Standard hours are 7am–5pm Monday to Friday. No weekend work unless the project timeline requires it, and residents are notified in advance. After demolition, the remaining work (membrane, tiling) is significantly quieter.

3

Dust and debris

Demolition generates dust. We use dust barriers, extraction fans, and daily clean-up to contain it. Common areas are protected with hoarding and drop sheets. If dust is entering your unit through doors or windows near the work zone, tell the site supervisor immediately — we’ll adjust the containment.

4

Communication during the project

Your strata manager receives weekly progress reports with photos and an updated timeline. If anything changes — a delay, an additional defect found during strip-back, a schedule adjustment — it’s reported before the end of that week. Residents can contact the site supervisor directly for day-to-day questions.

Think of it this way

It’s like renovating a restaurant without closing it. The kitchen keeps running, guests keep dining, but the back section is behind hoarding getting rebuilt. Every night the doors still open. The work happens around the service — not instead of it.

That’s how waterproofing works on an occupied building. Residents stay in their apartments. The building stays operational. But one section at a time goes behind the barriers, gets fixed properly, and comes back better than it was.

Investment

Typical timelines and what drives cost

Every waterproofing project is different, but here are the ranges your committee should expect when budgeting and planning.

Typical project duration

A single balcony takes 3–4 weeks from strip-back to handover. A building with 10–20 balconies, staged in groups of 2–4, typically runs 4–6 months. Rooftop waterproofing on a mid-rise building is usually 6–8 weeks. Timeline depends on access, weather sensitivity of the membrane system, and how many areas need concurrent work.

What drives the cost

The biggest cost variables are: number of balconies or wet areas, condition of the substrate (more cracks = more repair), membrane system specified by the engineer, and tile selection. A single balcony waterproofing project typically starts from $15,000–$25,000. A full building program across 10–20 balconies ranges from $250,000–$600,000 depending on scope and building access requirements.

Put it in perspective: if a single unit in your building is worth $800K–$2M, and water ingress is actively damaging the slab, the ceiling below, and the common property — a properly specified waterproofing remediation protects millions in combined property value. The cost of not fixing it compounds every time it rains.

The real cost of getting it wrong

We’ve inherited waterproofing projects where the previous contractor applied a liquid membrane over existing tiles without stripping back. The membrane failed within 18 months. The owners corporation paid for the original work, then paid again to strip everything back (including the first contractor’s membrane), then paid a third time to do it properly. Three invoices for one balcony — because the first contractor skipped the process this page describes.

Common Questions

Questions from residents and committees

Can you waterproof without ripping out all the tiles?
Sometimes, depending on the situation. But if the membrane underneath has failed, there’s no shortcut that lasts. A liquid membrane over existing tiles might hold for 12–18 months — but it’s not a long-term fix.

We’ll tell you honestly whether a targeted repair will hold or whether you need a full strip-back. The engineer’s report determines that — not us.
How long will each balcony be out of action?
Typically 3–4 weeks from strip-back to handover. The loudest part (demolition) is 2–3 days. After that it’s quieter work — substrate repair, membrane installation, tiling.

We stage balconies in groups so most residents still have access to theirs while others are being done. You’ll get at least two weeks’ notice before your balcony is scheduled.
We had this fixed two years ago and it’s leaking again. Why?
Almost certainly because the root cause wasn’t addressed. Common reasons previous repairs fail: liquid membrane applied over existing tiles instead of strip-back, upturns not taken high enough at walls, penetrations not properly sealed, or falls not corrected so water pools instead of draining.

That’s exactly why we work from an engineer’s specification — it identifies the actual failure mechanism, not just the visible symptom.
Will there be noise on weekends?
Standard working hours are 7am–5pm Monday to Friday. No weekend work unless the project timeline requires it — and in that case, residents are notified in advance and demolition work is not scheduled on weekends.

Council noise regulations apply at all times.
Can I still use my apartment during the works?
Yes. Residents stay in their apartments throughout. The only area you lose temporary access to is the balcony or wet area being worked on. Front doors, kitchens, bathrooms (unless the bathroom is the area being waterproofed) — all remain accessible.

If a bathroom is being remediated, we coordinate alternative arrangements with your strata manager before works begin.
What warranty do we get on the new waterproofing?
You receive a written workmanship warranty from Atomic Projects, plus the membrane manufacturer’s product warranty (typically 10–25 years depending on the system specified). Both are included in your handover documentation pack.

The compliance documentation — declared designs, QA records, and the engineer’s sign-off — also forms part of your building’s permanent record under the DBP Act.
Why does Atomic Projects publish this level of detail instead of just quoting the job?
Because informed committees make better decisions. If you understand the process, you can evaluate quotes properly, ask the right questions of any builder you’re considering, and hold your contractor accountable to the methodology.

We’d rather you understood exactly what good waterproofing looks like — and then chose whoever delivers it best. We think that’ll be us, but the knowledge belongs to you either way.

Need help with your building?

Start with a conversation. We’ll visit your building, assess the situation, and give you a clear path forward — free, no obligation.

Call us on 0410 515 509 or fill in the form on our waterproofing page. We’ll tell you whether you need an engineer first or whether we can assess your building directly.

No obligation. We respond within 24 hours.