Waterproofing Sydney

Where water actually gets in

Most Sydney water damage enters through a handful of predictable details. Balconies leak at the wall-to-floor junction, at door thresholds and around balustrade fixings, where the original membrane was terminated short or has simply reached the end of its life. Parapet walls let water in through cracked capping and open mortar joints, then feed it down inside the wall cavity.

Planter boxes built against walls are the quiet offender: soil holds moisture against the structure permanently, and an unlined or failed planter wicks it straight into the adjoining room. Porous and cracked render is the broadest entry point of all. When an east-coast low drives rain horizontally, unsealed render absorbs it across the entire face of the wall, and hairline cracks turn into supply lines.

The membrane and coating systems we apply

For balconies, planter boxes and other horizontal details we use liquid-applied membranes. Applied by brush and roller in multiple coats, a liquid membrane cures into a seamless rubber-like layer that follows every junction, upstand and penetration, the exact places sheet products and aged membranes fail. Trafficable versions take foot traffic and a decorative finish on top.

For walls we use elastomeric coatings: high-build acrylic systems applied at several times the thickness of conventional paint. They bridge hairline cracking, flex as the building moves through the day, and stay breathable, letting trapped moisture vapour escape while blocking liquid water from getting in. Preparation follows the same discipline as any coating we apply: the substrate is cleaned, repaired and primed, because a membrane bonds no better than the surface under it.

The signs you need waterproofing, not just paint

Buildings signal water entry long before a ceiling drips. Render sounds drummy, a hollow note when tapped, where moisture has broken the bond behind it. Paint bubbles and blisters as water pushes it off the wall from behind. Efflorescence, the white powdery salt on brick and render, is left behind by water travelling through the masonry and evaporating at the surface.

Below balconies, look for tide marks, drip stains and rust tracking from balustrade fixings. Inside, a musty smell against an external wall means the moisture has already made it through. Every one of these is a waterproofing problem wearing a paint problem’s clothes, and repainting over any of them fails within a season, because the water is still moving.

Waterproofing and repainting belong together

The most common waterproofing mistake in Sydney is decorating over a live leak. Fresh paint hides the staining for a few months, the moisture keeps moving, and the new finish blisters exactly where the old one did. The sequence has to run in order: find the entry point, seal it, let the substrate dry, then decorate.

Because we are painters first, both halves happen in 1 engagement. The membrane and the repaint are quoted together, the wall coating colour is resolved through the free colour consultation valued at $275 that comes with every quote, and the finished wall looks like a repaint rather than a repair. The same contractor is responsible for the whole result, which is precisely what a leak repair needs.

Strata balconies and common-area waterproofing

Apartment buildings concentrate every waterproofing risk on this page: rows of identical balconies ageing at the same rate, planter boxes in common landscaping, and parapets and facade render reaching the end of their service life together. When 1 balcony leaks into the unit below, its neighbours are rarely far behind.

For owners corporations we scope this work the way committees need it: a building-wide inspection, a clear list of which balconies and details need membrane work now and which can wait, and pricing structured so the works stage across budgets. Membrane coatings sit naturally inside a facade repaint, and doing both together saves the cost of accessing the same elevations twice. Our strata painting service covers the painting side of those programs.