Expansion joints in the CPWD Delhi Schedule of Rates
Government and PSU tenders specify building expansion joints by DSR item number: 5.44 for floors, 5.45 for walls and 5.46 for roofs. This page sets out what each item asks for, which system we make in India against it, and the six things the item leaves unsaid that a BOQ should state.
What 5.44, 5.45 and 5.46 cover, and what we supply against each
Each item is a supply-and-fix item measured in running metres, split into sub-items by gap width: .1 for 100 mm, .2 for 150 mm and .3 for 200 mm. The numbering has held in every DSR edition we have quoted against since 2018.
| DSR item | Location | What the item asks for | We supply | Gap range (data sheet) |
|---|---|---|---|---|
| 5.44 Floor joint | Floor to floor, floor to wall | Extruded aluminium base members with a self-aligning, self-centering cover plate that moves in all directions, including vertically; a moisture barrier membrane in the joint | MegAtec 340 A01 floor to floor A02 floor to wall | 25–300 mm |
| 5.45 Wall joint | Wall to wall, wall to corner, internal or external | Extruded aluminium base members with a self-aligning arrangement, light profiles with minimal exposed aluminium, and no tendency for components to slip down the wall | MegAtec 360 A07 wall to wall A09 corner and ceiling | 25–200 mm |
| 5.46 Roof joint | Roof to roof, roof to wall | A watertight self-centering cover that resists UV, airborne contaminants and maintenance foot traffic; a moisture barrier membrane is stated as mandatory | MegAtec 610 A01 roof to roof A02 roof to wall | 25–300 mm |
All three are made at our New Delhi works in 6063 aluminium (T5 and T6), the alloy the items name, and all three are rated for ±50% of the nominal gap on their A01 and A07 joints. The data sheets are linked from each product page and from the downloads centre.
Three phrases in the items that decide the system
“Self aligning / self centering”
This is the floor item’s defining requirement: a cover plate held central over the gap by its own mechanism, so it does not drift to one side as the gap opens and closes. The MegAtec 340 does this with a centering bar under the plate. A fixed-plate floor joint is a different system, whatever the gap.
“No slipping down tendency”
A wall joint hangs on a vertical face for the life of the building. The item asks that nothing in it creeps downward under its own weight. The MegAtec 360 is a low-profile, 16 mm high wall system with no visible fixings, for internal and external walls.
“Watertight … mandatory”
The roof item is the only one that calls the membrane mandatory in so many words. The cover sheds water; the membrane under it is what keeps the roof dry. The MegAtec 610 is a raised external centre-plate roof joint, built to be walked on by maintenance staff, not trafficked.
Six things to state in the BOQ, because the DSR item does not
A DSR item is written to be priced, not to be designed from. It names the location and the gap and stops there. These six gaps are where a tender and a site part company, and each one costs less to settle in the BOQ line than on site.
- Gaps outside 100–200 mmThere is no sub-item above 200 mm, so a wider joint becomes a non-scheduled item with its own rate analysis. Below 100 mm, some tenders bill under .1 and some treat it as non-scheduled; say which. Our floor and roof systems go to 300 mm, the wall system to 200 mm.
- The movement, in millimetresThe items ask for multidirectional seismic movement but give no figure. State the movement each location must take, from the bay length, temperature range and seismic case. The movement calculator works out the thermal part.
- The traffic on floor joints5.44 mentions “load application areas” but names no load. Say what crosses the joint: people, trolleys and beds, or vehicles. The 340’s data sheet gives load ratings for gaps up to 75 mm; for wider joints carrying wheeled loads, tell us the traffic and we confirm the system before you price it.
- The finish thicknessA floor joint sits flush with the finish, so its height has to match it. The 340 is made in 25, 38 and 50 mm heights. State the finish build-up, or the joint arrives proud of the floor or sunk below it.
- Fire compartment linesNone of the three items includes a fire barrier. Where a joint crosses a compartment line, the barrier is a separate item with its own rating and must be written in separately. Otherwise it is simply not supplied.
- The membrane on wall joints5.44 and 5.46 call for a moisture barrier; 5.45 does not mention one. On an external wall the joint needs one as much as the roof does. Add it to the line.
A BOQ line that leaves nothing to interpretation
Keep the DSR item number and its description, then add one line per location that fills the six gaps above. For example:
| Item | Location and duty | Reference or equivalent |
|---|---|---|
| 5.44.2 | Floor to floor, 150 mm gap, ±75 mm movement, 38 mm finish, pedestrian and trolley traffic, with moisture barrier membrane | MegAtec 340-A01-150, 38 mm height |
| 5.45.1 | External wall to wall, 100 mm gap, ±50 mm movement, with moisture barrier membrane | MegAtec 360-A07-100 |
| 5.46.2 | Roof to wall, 150 mm gap, ±75 mm movement, watertight with moisture barrier membrane | MegAtec 610-A02-150-025 |
The references follow the product numbers in our data sheets. If you would rather not name a manufacturer, the specification clause on the specifiers page turns the same duties into testable requirements.
What to ask for at submittal
The items leave the make to the Engineer-in-Charge. These are the documents that let an engineer approve a joint on evidence rather than on a brochure.
- The data sheet for the exact joint, showing the gap range, movement capacity and the product number being offered.
- The cross-section for each location, with the blockout width and depth the slab or wall must leave.
- The method statement: levelling bed, fixings, membrane and protection. What it should state.
- A joint schedule naming every location, its gap, its movement and the joint reference against the DSR sub-item.
- Who installs it. We supply and fix with our own crews, so one company answers for the joint and its fixing.
Related guides
Send the tender items. Get them answered line by line.
Send the BOQ pages with the DSR items, or the drawings. We return the system, joint reference and movement against each sub-item, and quote to supply and install.