Façade Re-Caulking & Sealant Replacement Melbourne
Panel joints, window perimeters and expansion joints — failed sealant cut out and replaced properly via rope access. No scaffold, no overbridging, no leak coming back next winter.
Sealant is what actually keeps the water out.
Every junction on a façade — panel to panel, frame to structure, slab edge to cladding — relies on a bead of sealant a couple of centimetres wide to keep the weather out while the building moves underneath it. That bead has a service life, and on Melbourne buildings it's usually the first envelope component to fail: UV breaks the polymer down, thermal cycling works the joint daily, and one season the bead that looked fine cracks, chalks or peels off the substrate. Nothing dramatic happens — until wind-driven rain finds the gap.
360 Access replaces façade sealants via rope access across Melbourne: our technicians descend the joint lines directly, so a re-caulking programme that would otherwise justify scaffold or a swing stage becomes a crew on ropes working elevation by elevation. Spot repairs to a single leaking window perimeter, full-elevation joint replacement, or a staged whole-building programme — same method, scaled to the failure.
Every joint type on the envelope.
Joints we reseal
- Precast and panel joints
- Window and curtain-wall perimeters
- Expansion and control joints
How we do it
- Full cut-out of failed sealant
- Surface prep, primer and backer rod
- Tooled bead, matched to substrate and movement
Why rope access
- No scaffold or swing stage
- Spot repair to whole-building programmes
- Photo documentation of every drop
How sealant tells you it's finished.
Sealant failure is progressive and visible — if someone is close enough to see it. The usual sequence:
- Chalking. UV degradation leaves a powdery film on the surface. The bead still looks intact from the street, but the polymer is breaking down and elasticity is going with it.
- Cracking and crazing. Surface cracks open across the bead as it hardens. Each crack is a capillary path for water.
- Adhesive failure (delamination). The sealant peels cleanly off one side of the joint — often visible as a dark shadow line along the bead. The joint is now open, whatever the sealant's condition.
- Cohesive failure. The bead splits through its middle as joint movement exceeds what the aged material can absorb.
- Leaks and staining. Water inside during wind-driven rain, or staining runs below joints outside. By this stage the sealant has usually been failing for years.
Because these signs show up close-up long before they show up as leaks, sealant condition is one of the things we log on every façade maintenance programme — the difference between a planned re-caulking scope and an emergency one is usually just who noticed first.
Cut it out and replace it. Never bridge over it.
The shortcut that ruins re-caulking jobs is overbridging — running a new bead over the old one, or painting over failed joints to tidy the look. It fails because sealant is only as good as what it's bonded to: new material over a chalky, delaminating substrate inherits that substrate's failure, and the joint opens again at the same interface within a couple of seasons. You pay twice and the water never stopped.
Our method is the manufacturer's method, every joint: cut out the failed sealant completely; grind or clean the joint faces back to sound substrate; prime where the substrate requires it; install a new backer rod to set the joint's width-to-depth geometry so the bead can actually stretch; then gun and tool the new sealant — polyurethane or silicone, selected for the substrate, exposure and movement class of that joint. Batch numbers, coverage and elevations are recorded, and adhesion is checked as the work proceeds. It's slower than bridging over the top. It's also the version that lasts its rated life.
What lifespan to plan around.
Sealants are consumables with predictable lives, which makes them one of the easiest façade components to budget properly. Generic façade sealants degrade under UV in around 8–12 years. Quality polyurethane joint sealants run 10–15 years. Structural silicone — the material doing the quiet heavy lifting on glazed curtain walls — commonly exceeds 20. Exposure skews all of it: north- and west-facing elevations cop the UV and the weather, and high-movement joints age faster than sheltered ones, so a staged programme that replaces the worst elevations first usually beats a single whole-building hit.
If a building has passed the ten-year mark on original sealants and nobody has looked closely since practical completion, assume the joints are due for assessment. Our work on the Astorial (668 Swanston Street, Carlton) is the standard example — façade refurbishment where systematic sealant replacement, delivered on ropes, brought a tired envelope back to weather-tightness without scaffolding the building. For the full failure mechanics, see our guide on how façade sealants and gaskets fail.
Chasing a leak? Diagnose before you reseal.
Failed sealant is the most common single cause of water ingress on Melbourne high-rise — but water is a liar. It enters at one joint, tracks along slab edges and framing, and presents metres away from the breach. Resealing the joint above the stain is how buildings end up paying for the same leak three times.
So where leaks are the driver, we start with water ingress investigation: locate the actual entry point, prove it, then cut out and replace the sealant that's letting water in. It's the discipline behind our Docklands programme — over 400 individual leaks traced and resolved across eight years on the same waterfront buildings, the majority terminating at failed joints and perimeter seals. Where the investigation finds more than sealant — cracked render, spalling concrete, failed flashings — the scope hands across to our façade repairs crews rather than stopping at the bead.
Re-caulking FAQs
How long does façade sealant last?
Generic façade sealants degrade under Melbourne UV in around 8–12 years. Quality polyurethane joint sealants typically last 10–15 years, and structural silicone can exceed 20. Exposed, high-movement joints on north- and west-facing elevations age fastest — sealants rarely all fail at once, which is why staged replacement programmes work well.
What are the signs façade sealant has failed?
Cracking or crazing across the surface, chalking (a powdery film that rubs off), delamination where the sealant peels away from one side of the joint, hardening and loss of elasticity, staining runs below joints, and — the sign nobody misses — water inside during wind-driven rain. Any one of these means the joint is no longer sealing.
Can you just paint or smear over the old caulking?
No — and be wary of anyone who offers to. Overbridging traps the failure underneath: new sealant bonded to a chalky, delaminating substrate fails at the same interface, usually within a couple of seasons. The correct method is full cut-out, surface preparation and priming, a new backer rod, then a tooled bead of the right sealant for the substrate and movement class.
Will re-caulking stop our leaks?
Failed sealant is the most common single cause of façade leaks, so often yes — but not always, and guessing is expensive. Water tracks, and the joint that's leaking isn't always the joint above the stain. We diagnose first through water ingress investigation, confirm the entry point, then replace the sealant that's actually letting water in.
Joints past their service life?
Tell us the building, what you're seeing and where — we'll respond within one business day.
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