Façade, Window & Expansion Joint Leak Detection

Some façade leaks depend on the weather — and those are the hard ones.

A perished joint or an open crack will let water in during ordinary light rain, with no wind at all. Others behave completely differently: they stay dry through weeks of weather and only let go when rain arrives from one particular direction, in enough volume, with enough wind pressure behind it to drive water somewhere gravity alone would never take it. The same elevation can have both, and they do not look any different from the outside.

That is what makes façade leaks difficult. One that needs a specific combination of conditions might surface two or three times a year, and an inspection on a fine day finds nothing whatsoever. Knowing which conditions a particular defect needs — and then reproducing them on demand — is where the equipment and the years on buildings actually earn their keep. It is rarely quick, and anyone who tells you otherwise has not done many.

It is also why these leaks get misdiagnosed as plumbing, as balconies, or as condensation. Those behave differently again, and none of them are fixed by re-sealing a façade.

Where a façade lets water in

• Expansion and control joints — the sealant is a consumable. Ten to fifteen years is a typical service life, less on a hot north or west elevation, and a perished joint is a continuous open path into the wall.
• Cracked render over block work — render cracks track the substrate. A crack that follows a mortar line is telling you something different from one that runs straight across blocks.
• Window and door perimeters — the interface between frame and wall, where two trades met and neither owned the junction. Head flashings, sill pans and end dams are the details most often missing.
• Window frames themselves — corner joints in the frame, failed glazing seals, and drainage slots blocked by paint or debris so the frame fills instead of draining.
• Parapets and copings — the top of a wall is exposed on three sides, and a coping joint that has opened admits water directly into the wall core.
• Penetrations — brackets, signage fixings, air conditioning penetrations, conduit entries, redundant fixings left in place when something was removed.
• Slab edges and construction joints — the horizontal line where one pour met the next, often the exact line efflorescence appears along.

Two of the ways a failed joint presents. The first has perished — the surface crazes as the material hardens and loses the elasticity the joint depends on. The second is adhesion loss: the sealant is still sound but has released from one face, leaving an open path straight in.

What sits behind them varies, and it is rarely one thing — surface preparation, no primer where the substrate needed one, the wrong product for the material, a joint never formed deep enough to take the movement it has to absorb, application onto a damp or dusty face, UV and chemical exposure, or simply age. Which of those it was decides whether a replacement lasts fifteen years or fails again in two, and it is why this is never a patching job: the old material comes out, the joint is prepared and re-formed, and new sealant goes in — the third image.

Investigating it properly means getting to it

A façade cannot be assessed from the ground. Binoculars and a drone photograph tell you a joint exists; they do not tell you whether the sealant has lost adhesion on one face, whether the backing rod is missing, or whether a crack passes through the render or only across its surface.

Our technicians are IRATA certified, so the inspection happens with hands on the actual detail — at every level, on every elevation, without scaffold, and at a fraction of the cost and disruption.

How we prove the path

Not the window. The wall and carpet look dry. The thermogram shows water tracking down from the sill and spreading into the floor, and the obvious conclusion is that the window has failed. That conclusion gets windows replaced — at considerable expense — while the leak carries on exactly as before. We see it often.

On this job it was hairline cracking in the render outside. Water was entering the wall above, running down inside it, and surfacing at the sill because that is simply where it met something that stopped it. Establishing that took rope access and a close visual inspection of the façade, controlled water testing, and thermal imaging inside while the testing ran. The thermogram showed where the water was arriving. It could not show where it got in — no single method can.

The report a body corporate can actually use

Façade remediation is expensive and contentious, and the difference between re-sealing four joints and re-sealing an elevation is tens of thousands of dollars. A survey that says "the façade needs attention" is not a scope. What a committee needs is defect locations recorded against elevation drawings, photographs at close range, moisture readings that support the conclusion, and a prioritised repair sequence.

That is what we deliver, and it is what turns an argument into a decision.

Leak detection & rectification on the same set of ropes

Because the same crew is licensed for remedial work and waterproofing, joint replacement, crack repair, render patching and re-sealing can be carried out from the same rope set-up as the inspection — no second mobilisation, no scaffold, no second contractor reinterpreting someone else's findings.

Full-height joint replacement. An expansion joint being re-sealed over its entire vertical length from a single rope set-up — old sealant cut out, joint prepared, adhesion promoter applied, backing rod set, and new high-quality polyurethane sealant run all the way down.

That third step is the one most often skipped. Adhesion promoter is an extra product, an extra pass and extra time on the ropes, and a finished joint looks identical without it. Manufacturers specify it by substrate for a reason: on most façade materials it is what the bond depends on. Skipping it is a common cause of exactly the adhesion loss in the photographs above — and it is the difference between a joint that reaches the service life it was quoted for and one that does not.

Why the stain is nowhere near the defect →