Lift Shaft and Staircase Openings in Existing Slabs

Cutting a lift shaft or staircase opening into an existing RCC slab is one of the more demanding jobs we take on, because it usually means cutting through multiple floors in a building that is often still occupied. The short answer to how it is done: we mark and verify the opening against structural drawings, install temporary propping below the cut line, cut the slab in a sequence that never leaves a large unsupported panel, and remove the concrete in manageable sections using core drilling at the corners and diamond wall saws or track saws for the straight runs.

This is fundamentally different from a single-floor wall opening. A retrofit lift shaft typically runs through every floor slab in a stack, so the plan has to consider load paths, the sequence in which floors are cut, and how debris and equipment move vertically through a building that may still have residents or staff on other floors. Get the sequence wrong and you risk cracking adjacent slab sections or overloading a temporary support.

We have executed this scope for residential towers and mid-size commercial buildings around Gurugram, including retrofit lift additions in older DLF Phase blocks and staircase widening in Sector 56 commercial plots. Before any cutting starts, review our full core cutting services and see the service areas we cover.

Why lift shaft cutting is a structural job, not just a cutting job

A slab that has stood for twenty or thirty years is carrying load in a pattern the original engineer designed for. Removing a two-metre by two-metre section for a lift car changes that pattern permanently. This is why every lift shaft or major staircase opening needs a structural engineer's sign-off before cutting, addressing beam reinforcement continuity, whether an edge beam or steel trimmer is needed around the new opening, and how load is redistributed to adjacent columns. We explain the approval process in detail in structural approvals for slab openings; if you are still at the planning stage, read that first.

Once we have a signed drawing, our role is to execute exactly what is specified, not to freelance on opening size or position. Any change we notice on site, such as an embedded conduit or an unexpected beam, is flagged back to the engineer before we deviate from the drawing.

Typical sequence for a multi-floor lift shaft

1. 1Site survey and rebar scanning on every floor to confirm slab thickness, reinforcement layout and locate any post-tensioned cables (rare in Gurugram residential stock but common in some commercial towers).
2. 2Temporary propping installed below the opening on the floor being cut and often the floor below, using adjustable steel props and load-spreading plates.
3. 3Perimeter drilling: core holes at all four corners of the opening act as stress relief points and give the wall saw blade an entry and exit path.
4. 4Wall saw or track saw cuts the straight edges of the opening, working top floor down or bottom floor up depending on access and crane/hoist position.
5. 5Sections are lifted out using a chain block or mini crane rather than dropped, protecting the floor below and controlling dust.
6. 6Edge finishing, trimming steel and handover to the civil team for edge beam casting or steel channel fixing.

Staircase openings: what is different

Staircase openings are usually rectangular and repeat on every floor at the same location, which helps planning but adds a different risk: staircases are often the only fire escape in a building, so we coordinate closely with the client to keep at least one route open at all times, cutting one flight or one floor at a time rather than opening the entire stair void in one pass.

Widening an existing staircase opening, common when upgrading fire compliance in older commercial buildings, is generally simpler than a fresh opening because part of the void already exists; we are extending an edge rather than cutting a fully enclosed hole, which reduces the amount of core drilling needed at corners.

Shoring and load management

Propping is not optional and it is not a formality. We size props based on the slab's dead load plus the construction live load (workers, tools, debris staged temporarily) using standard safety factors, and we never remove props until the engineer confirms the new edge beam or steel trimmer has achieved adequate strength, which for cast-in-place concrete usually means a minimum curing period before load transfer.

Dust, noise and working in occupied buildings

Because these jobs often run in buildings with people living or working on other floors, we run wet-cutting wherever the equipment allows it, which controls silica dust at the source; see our detailed note on dust-free cutting methods. Noise cannot be eliminated with a diamond saw, but we schedule the loudest cutting windows in coordination with the building management, typically avoiding early morning and late evening hours in residential societies.

On a stacked lift shaft job the biggest risk isn't the cutting, it's sequencing. Cut two floors out of order and you can undermine a prop that's holding up the floor above it.

Cost factors specific to lift shaft and staircase openings

Pricing for this scope depends heavily on the number of floors, slab thickness, reinforcement density and access for debris removal. As a rough indicative range for a typical residential tower lift shaft opening per floor, expect costs in the range of ₹18,000 to ₹35,000 per floor including propping labour, though this varies with site conditions; always confirm on a site-specific quote. For the general pricing structure across our services see the core cutting cost guide.

• Number of floors and total vertical run of the shaft
• Slab thickness and reinforcement density (older buildings sometimes have unusually heavy rebar)
• Access for debris removal — ground floor lobby cutting is far easier than a 12th-floor cut with no functioning lift
• Whether propping design and edge beam casting are in our scope or handled by a separate civil contractor
• Working hour restrictions imposed by the RWA or building management

Choosing the right team for this scope

Not every core cutting outfit is set up for multi-floor structural openings. Ask any contractor you are evaluating whether they routinely work with a structural engineer, whether they carry rebar scanning equipment, and whether they can show completed projects of similar scope. Our related post on choosing a core cutting contractor covers the questions worth asking before you sign a work order.

Get your lift shaft or staircase opening planned properly

If you are adding a lift, retrofitting a staircase or widening an existing opening anywhere in Gurugram, Sohna Road, Manesar or the DLF belt, talk to us before finalising your engineer's drawing so the cutting sequence is realistic on site. Contact us for a survey, or call +91 9735 156 388 / WhatsApp for a quick assessment.