Expansion joint repair and replacement
For joints that rattle, have lifted, have let the finish tent alongside them, or have started leaking into the floor below. We survey before we quote and work out what the joint should have been. We put the slab edge right before anything new goes in, so the replacement outlasts the joint it replaces.
Most joints we replace are twenty years old and in a live building
India built a great deal between the late 1990s and the mid 2000s, and the movement joints in those buildings are now at the end of a service life nobody planned for. The calls come from facility managers of malls and hospitals, estate engineers of IT parks and station managers, and what they describe is usually one of these three.
A rattle or a lifted cover
A cover that clicks under a trolley, or one end standing proud of the finish. Usually a fixing that has lost its grip. This is the cheapest moment the building will ever offer to fix the joint.
Tiles tenting beside the joint
Usually a flooring failure that looks like a joint failure: the finish had no movement joint of its own over the structural one. We will tell you which it is before anyone re-lays a tile.
A stain or drip below
Water past the joint’s waterproofing, often surfacing metres away. Water at a slab edge corrodes reinforcement and softens the concrete the joint’s own fixings depend on.
The five signs, in the order they usually appear and with what to do about each this week, are in Is your expansion joint failing?
Survey, movement, substrate, system: in that order
The usual order is to pull the old joint out, measure the hole and order something that fits. That lets the damaged hole write the specification, and it is why so many replacements fail faster than the joints they replaced. Ours runs the other way.
- Survey, before anything is removedThe gap at three or more points along each run, with the temperature recorded at the time, and photographs end to end. Once the old frames are out, the evidence of the original condition is gone.
- Movement: what it should have beenThe movement worked out as if the building were new, from bay length, exposure, temperature range and the seismic case. That is then compared with what was installed. It tells us whether the old joint wore out, was under-specified, or was never the problem.
- Substrate: where remedial jobs failThe slab edge is cut back to sound concrete and the rebate rebuilt before new frames go in. While the joint is open we check for a membrane and for a fire-compartment line, because there will not be another chance.
- System: only nowChosen against the calculated movement and sized to the surveyed gap, not the drawn one. Then installed by our own crew.
The full reasoning, step by step, is in Replacing a failed expansion joint, in the right order.
What a remedial method statement for an expansion joint should cover
If you are writing one, or checking one a contractor has sent you, these are the items that decide whether the replacement lasts.
- Survey records: gap at three or more points per run, ambient temperature, photographs, and what lies below the joint.
- Movement check: the calculated movement against the rating of the system proposed, not just the gap it fits.
- Substrate reinstatement: how far the slab edge is cut back, the repair mortar, and the cure it needs before anchors go in.
- Waterproofing: whether a membrane is added or reinstated in the gap, and who owns the lap to the structural waterproofing either side.
- Fixing: anchor type and spacing into the reinstated concrete, and how they are tested.
- Sequencing: possession lengths, never opening more than can be reinstated in the same shift, and the safe temporary condition at each end of a run.
- Handover: each length returned clean and trafficable at the end of the possession.
Working while the building stays open
Almost every replacement is in a live building, and that constrains the method as much as the specification does. Work comes in short possessions, often at night. Each length has to be handed back clean and trafficable at the end of the shift, so the run is planned in sections with a safe temporary condition at each end.
An open structural gap in an occupied building is a safety issue and a water risk, so we do not take out more than can be reinstated in the same possession. On the Chennai Egmore concourse the station never closed at all.
Not every failure is a joint failure
In this market the aluminium is almost never what failed. What we find instead is fixings worked loose in a marginal slab edge, a membrane termination that was never formed, a tiled finish with no movement joint of its own, or a later fit-out that tiled over or drilled through a working joint. If the problem is the flooring, the waterproofing or the services rather than the joint, we will say so. Replacing the joint would not fix it.
Five things that let us tell you what has failed
- Photographs along the run and close up at the worst point, plus the stain below if there is one.
- Three gap readings per run and the temperature at the time. How to measure the gap properly.
- What crosses it: people, trolleys, beds, pallet trucks, cars.
- What is below: occupied space, a car park, a basement, or ground.
- When it started, and whether anything changed nearby before it did, such as a fit-out, re-tiling or new services.
Vexcolt India manufactures in India under licence from Vexcolt Ltd, UK, and installs with its own teams, so the survey, the joint and the fixing are one responsibility. If the old joint is another manufacturer’s, that changes nothing about the method.
The remedial guides
Send photographs. Get a diagnosis.
Photographs of the joint and the three gap readings are enough to start. We will tell you what has failed and what the replacement needs, before anything is quoted.