Most building managers in Sydney know the pattern. A unit reports water around a window frame or a damp patch on a ceiling, but only after a southerly or an east coast low. On a calm rainy day, nothing. A plumber checks the roof, finds nothing obvious, and the problem comes back with the next storm.
When a leak only shows up in wind-driven rain, the source is usually somewhere on the façade. Wind pushes water sideways and upwards into gaps that ordinary rainfall never reaches. Finding that gap on the side of a multi-storey building is the hard part.
Where water usually gets in
On the residential and commercial buildings we work on, façade water ingress tends to come from a short list of places:
- Window and door perimeter sealant. Sealant that has hardened, cracked or pulled away from the frame lets water track behind the frame and into the wall.
- Expansion and control joints. Failed joint sealant on concrete or render façades is one of the most common entry points we find.
- Cracks in render and concrete. Fine cracks let water in by capillary action, and wind pressure drives more through.
- Flashings and sill details. Missing, short or poorly lapped flashings direct water into the building instead of away from it.
- Balcony edges and slab junctions. Where a balcony meets the external wall, a failed seal or membrane edge can let water travel inside.
- Penetrations. Pipes, vents, air-conditioning lines and fixings through the façade that were never properly sealed.
Why these leaks are hard to trace
Water rarely appears directly behind the point where it enters. It can travel along a slab, behind cladding or down a cavity before it shows up as a stain one or two floors lower. That’s why a repair done only where the stain appears often fails.
Access is the other problem. The likely entry points are on the outside of the building, often several storeys up. Inspecting them properly from a balcony or from the ground is not possible, and putting up scaffolding just to look is expensive and slow for a strata committee.
How we investigate a façade leak
Our process on a typical leak investigation:
- Gather the history. Which units are affected, when it happens, which wind direction, and any previous repairs.
- Inspect the façade on rope access. A technician descends the affected drop and inspects sealant, joints, cracks, flashings and penetrations up close, photographing each defect.
- Water test the suspect areas. Water is applied to one area at a time, starting low and working up, while someone watches inside the unit. This isolates which detail is actually leaking instead of guessing.
- Report. The building manager receives a photo report showing the defects found, the confirmed entry point and the recommended repair.
- Repair and retest. Once the scope is approved, the repair is carried out on the same access setup where practical, then retested.
Why rope access suits leak work
Leak investigation is often a few hours of inspection and testing on a specific part of a façade. Rope access lets a technician reach that exact drop without scaffolding or a large EWP, and the same team can usually do the repair, whether that’s resealing a window, repairing a crack or replacing joint sealant. Where scaffold or an EWP is the better option for a particular building, we’ll say so at inspection.
What building managers can do now
- Keep a simple log of each leak report: unit, date, weather and wind direction. It makes the investigation faster and cheaper.
- Don’t rely on internal patching. Repainting a stained ceiling without fixing the entry point just hides the problem.
- Look for the warning signs on the outside: cracked or missing sealant, rust stains, efflorescence (white salt deposits) and drummy or cracked render. Rust stains and cracking can also point to concrete cancer.
- Plan a façade inspection before a repaint. Painting over failed sealant and open cracks locks the problem in.
Need a leak traced on a high-rise building?
Ace Abseiling carries out leak detection and water testing for strata and commercial buildings across Sydney, along with sealant replacement and concrete repairs. Request an inspection and send us the unit numbers and leak history.
