Expansion joint repairs and replacement
Cracked, split or missing expansion and control joints cut out and replaced from the rope, so the building can move without letting water in.
- Full cut-out, not overfill
- Correct joint depth
- Matched to the paint
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Expansion joint repairs in short
Tactical Height Solutions provides expansion joint repairs for buildings in Sydney using IRATA-certified rope access technicians instead of scaffolding. Cracked, split or missing expansion and control joints cut out and replaced from the rope, so the building can move without letting water in. Every job is supervised by an IRATA Level 3 technician, carried out under NSW contractor licence 478674C, and covered by $20 million public liability insurance. Site inspections in Sydney are free, enquiries get a reply the same day, and most jobs can start within 48 hours of an approved quote.
Updated October 2026 by Naldo Neto, IRATA Level 3 and licensed painter.
Expansion and control joints let a building move with heat, moisture and settlement. When the sealant in them hardens, splits or pulls away, water gets into the wall, cracks appear either side of the joint, and the joint becomes an obvious stripe down the façade.
We replace failed joints from the rope. The old sealant is cut out completely, the joint faces are cleaned and primed, a closed-cell backing rod sets the right depth, and new sealant is tooled to a profile that lets the joint move. Where render or paint along the joint is damaged, we patch and match it so the line disappears.
On a 4-storey residential building in Mascot we cut a new top joint, repaired the render and repainted the affected areas for a builder, all from ropes, without scaffold. See the Mascot project.
Licensing and regulated work
Our NSW contractor licence is in painting (478674C). On apartment buildings, concrete, render, sealant and waterproofing repairs over $5,000 may need a licence class other than painting, and remedial work on class 2 buildings falls under the Design and Building Practitioners Act, which needs an engineer's regulated design and a registered building practitioner. On those jobs we work as the specialist rope access contractor alongside your engineer and remedial builder. On commercial and industrial buildings, and for painting, cleaning and inspection work, we contract with you directly. We'll tell you at the inspection which applies to your building.
Why choose our expansion joint repairs
- Built to lastCorrect width-to-depth ratio and a bond-breaker, so the sealant stretches instead of tearing.
- Looks finishedRender patched and painted to match, so the joint line disappears.
- Every level, no scaffoldLong vertical joints are ideal rope access work.
- DocumentedPhotos of every joint before and after.
Façade defect rectification on a 4-storey residential building in Mascot
Stage 1 façade remedial works on a Mascot apartment building: joint and render repairs, balcony pipe penetrations sealed and a concrete patch repair, all from the rope, with a photo report for sign-off.
Read the case study
★★★★★We have worked with Naldo and the team on numerous projects involving abseiling works and have consistently found them to be highly professional and easy to work with.
Elias A., Google review
How the job runs
- Joint surveyWe check every joint for splitting, adhesion loss and water entry.
- Scope and priceLength of joint, sealant type and any render or paint repairs.
- Cut out and cleanOld sealant and loose edges removed.
- Prime, back and sealPrimer, backing rod and new sealant tooled to profile.
- Patch and paintAdjoining render repaired and painted to match.
Technical details
| Joint types | Vertical and horizontal expansion joints, control joints, joints between panels or materials |
|---|---|
| Materials | Polyurethane and MS polymer sealants, closed-cell backing rod, primers |
| Method | Full removal, primed faces, width-to-depth ratio to the sealant maker's guidance |
| Access | Rope access by IRATA-certified technicians from certified roof anchors |
Questions about expansion joint repairs
What is the difference between an expansion joint and a control joint?
Expansion joints let sections of a building move independently; control joints are planned lines that control where cracking happens. Both need flexible sealant that stays bonded as the building moves.
How do I know a joint has failed?
Look for splits down the middle of the sealant, gaps along the edges, hard or crumbling sealant, cracks in the render beside the joint, or damp patches inside near the joint line.
Can new sealant go over the old?
No. It will not bond properly and fails quickly. The old sealant has to be cut out completely first.
Can the new joints be painted?
Some sealants can be painted and some should not be. We choose a sealant in a matching colour or a paintable type to suit the finish.
See this work on real buildings in our projects, or read about our safety and insurance.