Specialist service · Melbourne-wide
Fire Rated Caulking in Melbourne
Gapless installs fire rated caulking — also called fire caulking, fire stopping sealant or FR caulking — in commercial, residential and industrial buildings across Melbourne. Over 10 years' experience. Fire rated systems from Pasco, APTC, Soudal, Bostik and Sika, installed to the manufacturer's specifications.
What is fire rated caulking and where is it used?
Fire rated caulking seals the joints, gaps and service penetrations in fire-rated walls and floors with sealants designed to resist fire — so the wall performs as a complete system, not a wall with holes in it. It's required wherever a fire-rated element is penetrated or jointed: apartment party walls, plant rooms, carpark ceilings, riser shafts, and head-of-wall junctions.
Service penetrations
Pipes, cables, conduits and ducts passing through fire-rated walls and slabs, sealed with the specified fire rated sealant.
Control & construction joints
Joints in fire-rated walls and between slab edges and facades, filled and sealed to maintain the wall's fire performance.
Head-of-wall & junctions
The gap between wall top and slab soffit — the detail that gets missed, and the one inspectors look at first.
Fire rated sealant vs normal sealant — what's the difference?
A standard silicone or acrylic sealant burns, melts or falls out of a joint in a fire, leaving an open path for flame and smoke. A fire rated sealant is formulated to stay in place and resist fire — many are intumescent, meaning they expand when heated to close the gap harder. Fire rated products from manufacturers like Pasco, APTC, Bostik, Soudal and Sika are tested by those manufacturers to Australian fire test standards, and each product's data sheet specifies exactly how it must be installed — joint depth, width, backing material — for that performance to hold. That installation detail is our job, and it's the part experience shows in.
Straight answer on certification: Gapless are experienced fire rated caulkers — we're not a certifying authority and we don't issue compliance documentation. We install the specified product to its manufacturer's specification and can tell you exactly what went where. Sign-off of passive fire systems belongs to your building surveyor or fire engineer.
Want the full picture? Read our builder's guide: What Is Fire Rated Caulking?
The technical bit
What do FRL, AS 1530.4 and AS 4072.1 mean for fire rated caulking?
FRL stands for Fire Resistance Level — the minutes a building element resists structural failure, fire spread and heat transfer, shown as three numbers such as -/60/60 or -/120/120. AS 1530.4 is the standard manufacturers use to test that rating, and AS 4072.1 covers how penetrations and joints in fire-rated elements must be sealed to hold it.
- FRL (Fire Resistance Level): the minutes a fire-rated wall or floor keeps its structural adequacy, integrity and insulation — e.g. -/60/60 or -/120/120.
- Tested system: the exact combination of sealant, joint width/depth and backing a manufacturer has tested together. Swap one part out and the tested performance no longer applies.
- Intumescent: a sealant that expands when heated, closing the gap tighter as the temperature rises. Non-intumescent fire rated sealants resist fire without expanding.
- Head-of-wall: the deflection joint where the top of a fire-rated wall meets the slab or structure above, built to allow movement without losing fire performance.
- Service penetration: a point where a pipe, cable, conduit or duct passes through a fire-rated wall or floor.
- Backing material: what's packed into a joint before the sealant goes in — for fire rated work, usually mineral wool or fire-rated backer rod, not standard PE foam.
This is the detail that gets checked at caulking inspections, when a building surveyor or fire engineer compares what's actually in the joint against the specified tested system. The NCC requires fire-resisting elements — party walls, plant rooms, shafts — to maintain their FRL wherever they're penetrated or jointed. Installers work to the tested system; sign-off sits with the certifier.
Our process
How we install fire rated caulking
- Check the specification (or ask for one) so we know the fire rated product, joint width and FRL required.
- Clean out the joint or penetration and confirm the opening matches the tested system's dimensions.
- Install the specified backing material — mineral wool or fire-rated backer rod — to the correct depth.
- Apply the fire rated sealant to the manufacturer's tested joint profile, tooled to a clean, consistent line.
- Check coverage and finish against the product's data sheet, especially at penetrations and junctions.
- We record which product went into which joint so your certifier has what they need.
We run this same process from a single riser shaft up to a full commercial fit-out caulking package, where several trades are running services through the same fire-rated wall.
What's typically specified, by situation
Every job is different, and the product we install is whatever your specification names — but these are the product families and backings most commonly called up for common fire-rated details.
| Situation | Typical product family | Typical backing | Note |
|---|---|---|---|
| Head-of-wall deflection joint | Fire rated PU/hybrid or fire rated silicone | Mineral wool | Needs to allow for slab deflection without losing the seal. |
| Pipe/conduit penetrations | Intumescent acrylic or fire rated silicone | Mineral wool, sized to the pipe | Product often varies with pipe material — metal vs PVC. |
| Cable tray penetrations | Intumescent acrylic | Mineral wool packed around the cable bundle | Re-checked whenever cables are added later. |
| Control joints in fire-rated masonry | Fire rated silicone | Fire-rated backer rod | Joint width and depth are set by the tested system, not by eye. |
| Slab-edge / curtain wall perimeter | Fire rated PU/hybrid | Mineral wool | Also has to handle weather and movement, not just fire. |
| Fire-rated precast joints | Fire rated silicone or PU/hybrid | Fire-rated backer rod or mineral wool | Panel joint width is checked against the tested range before sealing. |
These are typical product families for planning purposes only, not a specification. The exact product, joint dimensions and backing named on your documentation always take precedence, and sign-off sits with your certifier or fire engineer — not with us.
Why builders use Gapless for fire caulking
- 10+ years of caulking experience including fire rated work — this is specialist work most general caulkers don't do day to day.
- Installed to spec: correct joint depth, correct backing rod, the product your specification names.
- Engineering-trained director who runs projects hands-on and trains every installer.
- Fully insured; SWMS, SDS and site-induction ready for commercial sites.
- Clean, labelled work — neat lines, no mess left for your finishing trades.
- 1–2 weeks' booking notice, and we work to your construction program.
Where we work
Areas we service for fire rated caulking
Gapless provides fire rated 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.
Fire rated caulking — frequently asked questions
What is fire rated caulking?
Fire rated caulking is the sealing of joints, gaps and service penetrations in fire-rated walls and floors using sealants designed to resist fire. Unlike standard silicone, fire rated sealants are formulated and tested by their manufacturers to maintain the fire resistance of the wall or floor they are installed in.
Are you certified fire caulking installers?
We are experienced fire rated caulkers, not a certification body. Gapless has over 10 years of caulking experience including fire rated work, and we install fire rated sealant systems strictly to the manufacturer's specifications. Certification and sign-off of passive fire systems sits with your project's fire engineer or building surveyor, not with the installer.
Do you provide compliance certificates or documentation?
No. We install fire rated sealant systems to the manufacturer's published specifications, and we can tell you exactly which product was installed where. Formal compliance documentation and sign-off is handled by your project's building surveyor or fire consultant.
What fire rated sealant brands do you use?
Mostly Pasco and APTC fire rated systems, and we also install Soudal, Bostik and Sika fire rated sealants. If your specification names a product, we install that product to its technical data sheet.
How much does fire rated caulking cost in Melbourne?
It depends on lineal metres, joint width and depth, the specified sealant system, access, and how much backing material is needed. We don't publish rates because no two jobs are the same — send the details through our quote form and we'll price it for free.
How much notice do you need to book fire caulking?
Typically 1–2 weeks' notice. Tell us your program dates when you request a quote and we'll work to them.
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 fire rated caulking 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.