Concrete and structural joint sealing for car parks, walkways, decks and high-traffic commercial sites. Built to move with the building.
Every concrete structure expands and contracts with temperature, settles over time, and flexes under load. Expansion joints are the engineered gaps that absorb that movement before it shows up as a crack somewhere expensive. The sealant in that joint has one job: stretch and compress through every cycle for fifteen years without losing adhesion to either side. It sounds simple. It is not.
Most failed expansion joints fail because the depth-to-width ratio was wrong, no backing rod was installed, or the product was over-tooled and locked into a three-sided bond. A three-sided bond cannot stretch, it tears at the substrate as soon as the joint moves. We size backing rod to the joint, install bond breaker tape where required, mask the edges, and apply at the correct hourglass profile for the joint geometry. The result is a joint that moves with the building for its full design life.
Seliecone seals expansion joints across Sydney commercial, civil and high-traffic residential sites. Car parks, walkways, balcony decks, pool surrounds, plant rooms, retail fit-outs. We supply compliance documents, MSDS and SWMS ahead of mobilisation, work to site programs, and coordinate with concreters, builders and project managers.
Every job covers the following as standard. Anything outside this list is quoted separately and confirmed before work starts.
Joint depth and width assessed
Substrate cleaned and primed where required
Closed-cell backing rod sized and installed
Bond breaker tape where two-sided bond required
Edges masked for a crisp line
Polyurethane or fire-rated sealant per spec
Tooled to correct hourglass profile
Fire-rated systems certified where required
Soudal and Pasco polyurethane sealants as the default for non-fire-rated expansion joints. For fire-rated penetrations and joints, certified and tested fire-rated systems supplied with full certification documentation. Backing rod is closed-cell polyethylene at correct diameter. Primers per manufacturer specification on porous substrates.
Areas we serve: We provide this service across all Sydney regions, including Sydney CBD, Eastern Suburbs, Inner West, North Shore, Northern Beaches, Western Sydney, Sutherland Shire and the Hills District. See all service areas.
Three things. Correct depth-to-width ratio (usually 1:2, twice as wide as it is deep). Backing rod installed to control depth and force the correct hourglass shape. And a two-sided bond, the sealant must adhere only to the two parallel joint faces, never to the back of the joint, otherwise it cannot stretch.
Expansion joints are full-depth gaps that allow movement between separate structural elements. Control joints are intentional weak lines cut into concrete to control where shrinkage cracks form. Both need sealing but with different products and depths.
Yes. We use certified and tested fire-rated systems for service penetrations, electrical box surrounds and structural joints between fire compartments. Certification documentation is supplied for building certifier sign-off.
Quality polyurethane sealants like those from Soudal accommodate up to 25% movement of the joint width. So a 20mm joint can tolerate 5mm of movement in either direction over time without failing.
Yes. Car park decks are one of our most common commercial scopes. We coordinate with property managers, schedule around tenant access, and use heavy-duty trafficable sealants designed for vehicle loads and UV exposure.
Commercial expansion joint work is priced per linear metre, with rates depending on joint size, sealant grade (standard vs fire-rated), height access and site conditions. Free quote after a site walk-through.
Tell us about the job, we come back with a written quote the same day, usually within an hour.
For trade enquiries, large jobs or anything time-sensitive, call straight through. Mon to Sat, 7am to 5pm.
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Get a quote, usually back to you the same day.
