Expansion Joint Treatment in Buildings
Leaking podium, terrace or wall joints re-sealed with polysulphide/PU systems, protected with joint tapes and finished with Dseal covers — by the group that manufactures the covers and has treated joints since 1987.
How a Failed Expansion Joint Announces Itself.
Expansion joints exist so the structure can move — with temperature, ground shifts and loading. The joint filler and sealant wear out long before the building does, and when they do, you see:
- Water staining or active leakage on the soffit below podium and terrace joints
- Sealant that has debonded, cracked or hardened and pulled away from the joint faces
- Damaged, loose or rattling joint covers on floors and walls
- Spalled concrete edges (broken arris) along the joint line
- Repairs done with rigid mortar across the gap — which the next movement cycle cracks open again
A joint is a designed movement gap. Any treatment that cannot move with it is not a treatment; it is the next leak.
What a Proper Joint Treatment Includes.
| Stage | What our crew does |
|---|---|
| 1 · Cut out | Remove old sealant and failed filler completely; rake the joint clean |
| 2 · Joint preparation | Grind and dry the joint faces; rebuild spalled edges so the sealant has sound concrete to grip |
| 3 · Backer rod | Insert closed-cell backer rod sized about 25% larger than the joint width, set to control sealant depth and prevent three-sided adhesion |
| 4 · Primer | Apply the primer matched to the sealant system and substrate |
| 5 · Re-sealing | Gun-apply two-part polysulphide (Fosroc Thioflex 600) or PU sealant; tool to a smooth concave finish; cure 24–48 hours |
| 6 · Tape bandage | Where waterproofing is critical, bond an expansion joint tape (EPDM/TPE) over the sealed joint as a second line of defence |
| 7 · Cover system | Replace or retrofit Dseal expansion joint covers — surface-mounted profiles suit retrofits with no blockout; recess-mounted covers need a blockout at least 5 mm deeper than the cover |
Material comes from our own counters — sealants, expansion joint tapes and Dseal cover systems — so specification and supply never argue with each other.
One-Part or Two-Part Polysulphide?
Polysulphide remains the reference sealant for building expansion joints — excellent flexibility, chemical resistance and adhesion, with a service life that often exceeds 20 years when applied on a properly prepared joint.
| One-component | Two-component | |
|---|---|---|
| Mixing | None — ready to gun | Base + curing agent, mixed on site |
| Cure | Slower; cures with atmospheric moisture | Faster, more predictable |
| Shelf life | ~12 months unopened at 4–27°C | 6–24 months by product |
| Best for | Small repairs, touch-ups | Larger projects and long joint runs |
Application needs dry conditions — which is why joint re-sealing is best planned before, not during, the monsoon. PU sealants are the alternative where paintability or tear resistance matters; we specify per joint, not per habit.
Sealant, Tape or Cover — Which Does Your Joint Need?
| Choose | When | Typical locations |
|---|---|---|
| Sealant re-fill | Joint edges are sound, gap is modest, a flush finish is wanted | Floor joints in lobbies, wall joints, parapet joints |
| Tape bandage | High movement, damaged edges, or waterproofing-critical decks where sealant alone will debond again | Podium and terrace joints, basement raft junctions |
| Cover system | Trafficked or visible joints, wide gaps — Dseal covers span 25 to 500 mm with EPDM/TPR inserts | Mall and hospital floors, facades, parking decks, seismic joints |
Most leaking podium joints get all three: seal, bandage, cover. For selection depth — movement classes, EPDM vs TPR — read the expansion joint selection guide or see the Dseal range we manufacture.
Expansion Joint Treatment FAQs.
How long does a polysulphide joint re-seal last?
Applied on a properly prepared joint — old sealant cut out, faces ground and primed, backer rod set — polysulphide sealants routinely serve for over 20 years. Preparation, not the cartridge, decides the life.
How long does the sealant take to cure?
Generally 24 to 48 hours. Two-component polysulphide cures faster and more predictably than one-component; trafficked joints are protected until cure is complete.
Why is water dripping below my podium joint when the terrace looks fine?
Because the joint is the lowest-resistance path through the slab. Once the joint sealant debonds, water travels along the gap and shows up metres away. Treating the ceiling stain achieves nothing — the joint itself must be cut out, re-sealed and usually tape-bandaged.
Do I need a cover plate, or is sealant enough?
Sealant handles the waterproofing; a cover protects the joint from traffic and gives a clean finish. Wide gaps, wheeled traffic and visible locations call for a Dseal cover system — surface-mounted retrofit profiles install without breaking the floor.
What does expansion joint treatment cost?
The NCR market range is roughly ₹1,400–3,000 per running metre, moving with joint width, sealant system, tape/cover additions and access (height work costs more). Send joint photos and lengths on WhatsApp for a quick estimate; the firm quote follows a site visit.