Melbourne-wide
Facade & Cladding Caulking in Melbourne
Weather sealing for ACP panels, cladding junctions and window perimeters. The facade is the building's raincoat — Gapless seals its joints with compatible, flexible sealant systems and clean lines that don't spoil the architecture. Over 10 years' experience, fully insured, EWP access where needed.
What is facade caulking and why does it fail?
Facade caulking is the sealing of movement joints in a building's exterior skin — the gaps between cladding panels, window frames, precast panels and slab edges — with flexible sealant that keeps water out while letting the building expand, contract and move without cracking. Done properly it's invisible; done badly it's the reason water is tracking down an internal wall three floors below.
Most facade leaks trace back to the same handful of causes: rigid filler or paintable acrylic used where a flexible sealant was needed, no backer rod behind the bead so it can't move without tearing, sealant gunned over dust, laitance or an old failed bead instead of a clean substrate, or the wrong sealant chemistry for the panel — acid-cure silicone will etch and stain some aluminium and precast finishes, which is why neutral-cure systems are the default on cladding. Sealants are also rated for how much movement they can absorb, typically expressed as a movement class of around ±25% or ±50% of the joint width — the wider the thermal swing a joint sees, the higher that rating needs to be.
Facade work usually means working at height — EWP, scaffold or swing stage — on a building that's occupied or trading underneath, so access planning and clean, controlled work matter as much as the sealant itself. Slab-edge and expansion joints get their own detailing separate from general panel joints; see our page on expansion and control joints for how those are sized and sealed.
What we seal on facades
ACP & panel joints
Panel-to-panel joints in aluminium composite and other cladding, sealed with substrate-compatible neutral-cure systems.
Window & door perimeters
Weather seals around frames — the most common water entry point on any facade.
Junctions & interfaces
Where cladding meets concrete, brick, flashing or a different material — movement joints that need flexible sealant, not rigid filler.
Why compatibility matters: the wrong sealant on an ACP panel can stain the finish or fail to bond. We match the sealant to the substrate using the manufacturer's data sheet — mostly Pasco and APTC systems, plus Soudal, Bostik and Sika.
Our process
How we seal a facade joint
- Inspect and measure. Joint width, depth, substrate type and the condition of any existing sealant, plus the access needed — EWP, scaffold or swing stage.
- Strip out and clean. Old or failed sealant is cut and scraped back to sound substrate; dust, laitance and residue are removed so the new sealant is bonding to clean material, not contamination.
- Set the joint geometry. Depth is checked against the 2:1 width-to-depth rule with a 6 mm minimum, and closed-cell backer rod is installed to hold that depth and stop three-sided adhesion.
- Mask and prime. Panel edges are masked for a straight line, and the substrate is primed where the sealant manufacturer's data sheet calls for it — common on porous concrete and some coated finishes.
- Apply and tool the sealant. The specified system — neutral-cure silicone for ACP and aluminium, or the matched product for the substrate — is gunned in full contact with both joint faces and tooled to a smooth, weather-shedding profile.
- Inspect and clean down. Masking is removed, the bead is checked for adhesion and finish, and surrounding panels are wiped clean.
Substrate matching
Which sealant suits which facade material?
The right sealant depends on what it has to bond to and how much that joint moves. This is the general logic we work from — the actual product on any job follows the manufacturer's specification for that substrate.
| Substrate | Typical sealant | Why |
|---|---|---|
| ACP / aluminium composite panel | Neutral-cure silicone | Won't stain the panel finish or etch the aluminium the way an acid-cure silicone can. |
| Powder-coated aluminium frames | Neutral-cure silicone, primed where specified | Coating systems vary — some need a primer for a durable bond, so we follow the frame manufacturer's data sheet. |
| Precast concrete & tilt panels | Polyurethane or neutral-cure silicone, movement-rated | These joints move with thermal cycling and settlement, so the sealant needs the ±25%–±50% movement capability to match. See precast panel caulking. |
| Glass / curtain wall glazing | Neutral-cure, structural-grade silicone | Needs UV stability and to sit compatibly against the glazing gasket and frame without attacking either. |
| Brick / render | Polyurethane or hybrid sealant | Copes with a coarser, more porous surface and generally takes paint better than silicone on painted render. |
| Flashings & metal trims | Neutral-cure silicone or compatible hybrid | Matches the metal's expansion rate and resists ponding water at horizontal junctions. |
Who this is for
Facade caulking for builders, contractors and building owners
Facade sealing gets asked for at different points in a building's life, by different people, for different reasons — new construction, an existing building drying out, or a strata committee chasing a leak.
- Builders closing out a facade package before handover — panel joints, window perimeters and slab-edge junctions sealed to program.
- Facade and cladding contractors who need a caulking subcontractor for an ACP, curtain wall or precast package rather than carrying the trade in-house.
- Strata and owners corporations dealing with an ageing or leaking facade — often worth starting with a caulking inspection to find every failed joint before re-sealing.
- Commercial landlords and facility managers maintaining the building envelope as part of ongoing upkeep, on their program and around tenants.
Where we work
Areas we service for facade and cladding caulking
Gapless provides facade and cladding caulking across Greater Melbourne and regional Victoria within about 90 minutes of the CBD. We travel to the job — commercial sites, apartment buildings, warehouses and homes alike.
Melbourne CBD & inner suburbs
Melbourne, Southbank, Docklands, Richmond, Collingwood, Fitzroy, Carlton, South Yarra, Port Melbourne, St Kilda.
West & north
Footscray, Sunshine, Werribee, Point Cook, Truganina, Laverton, Melton, Essendon, Broadmeadows, Epping, Craigieburn.
East & south-east
Box Hill, Doncaster, Ringwood, Glen Waverley, Clayton, Dandenong, Cranbourne, Frankston, Moorabbin, Cheltenham.
Bayside & Mornington Peninsula
Brighton, Sandringham, Mordialloc, Mornington, Mount Eliza, Rosebud, Dromana, Hastings.
Geelong & the west
Geelong, Lara, Corio, Torquay, Ocean Grove, Bacchus Marsh, Ballan.
Not on the list?
Ask. For commercial work we regularly travel further — send the suburb through the quote form and we'll confirm.
Facade sealing — frequently asked questions
What facade elements need caulking?
Panel-to-panel joints in ACP (aluminium composite panel) and other cladding, junctions between different cladding materials, window and door perimeters, and slab-edge interfaces. Each is a movement joint that must be weather-sealed with a compatible flexible sealant.
Which sealants do you use on facades?
Neutral-cure silicones and hybrid sealants compatible with the cladding material — mostly Pasco and APTC systems, plus Soudal, Bostik and Sika. Compatibility matters: the wrong sealant can stain panels or fail to bond, so we follow the manufacturer's data sheet for the substrate.
How much does facade caulking cost?
It depends on lineal metres, access (EWP, scaffold or abseil-free reach), and the sealant system. Send photos or drawings through the quote form and we'll price it free.
Wondering what this costs? See typical Melbourne rates per metre on our caulking cost guide — or skip straight to an exact price with a free quote.
Free quote · no obligation
Get a facade sealing quote
Tell us the suburb and roughly what needs sealing — we'll come back with a price or a call to clarify. Quotes are free; we typically book with 1–2 weeks' notice.
- 10+ years' specialist experience
- Fully insured · SWMS & induction ready
- Pasco · APTC · Soudal · Bostik · Sika systems
Got photos or drawings? Send them on WhatsApp or call 0414 824 987.