Load-Bearing Wall Removal — 1930s Semi-Detached, Stratford
Project type: Ground floor load-bearing wall removal Property: 1930s semi-detached, 3 bedrooms, Stratford E15 Client: Young couple creating an open-plan kitchen-diner Turnaround: 4 working days Structural engineer fee: £500 (fixed)
The Brief
The homeowner wanted to remove the wall between the kitchen and dining room to create a single open-plan space. It's the most popular home improvement we see — and for good reason. Opening up the ground floor transforms how a house feels and functions.
But this wall was clearly load-bearing. First floor joists ran perpendicular to it, and there was a wall directly above on the first floor. It was structural — no question.
What We Found on Site
The property was a typical 1930s semi — solid brick construction with a suspended timber ground floor and concrete strip foundations. The wall to be removed was a single-skin brick partition, 102mm thick, running the full width of the house.
Key measurements:
- Span of the opening: 4.2m (the full internal width, corner to corner)
- Load above: First floor joists spanning onto the wall, supporting one bedroom and a bathroom
- Floor above that: The loft had been partially boarded but was not converted — so loft loading was minimal
4.2m is a significant span for a domestic steel beam. Every extra 100mm of span increases the bending moment substantially. At this width, beam selection and padstone design need careful attention.
We also checked the walls at each end where the beam would bear. Both were solid brick external walls in good condition — adequate for the point loads we'd be introducing.
The Engineering
Load Takedown
We calculated the loads methodically:
- Dead load from first floor: timber joists + floorboards + plasterboard ceiling = 0.55 kN/m²
- Imposed load (bedroom): 1.5 kN/m² per BS EN 1991
- Self-weight of wall above: approx 2.1 kN/m run
- Loft loading (non-habitable): 0.25 kN/m² imposed
The total factored load on the beam was 28.4 kN/m UDL — not trivial.
Beam Design
We selected a 254×146×31 UB (Universal Beam) in S275 steel. The key checks:
- Bending: 94.6 kNm capacity vs 62.7 kNm applied — pass with comfortable margin
- Shear: 252 kN capacity vs 59.6 kN applied — pass
- Deflection: 7.2mm under service load, within span/360 limit of 11.7mm — pass
We could have used a smaller beam, but 254×146 gave us a better deflection performance. The extra cost of a slightly larger steel (maybe £30 more) is nothing compared to the peace of mind of knowing the ceiling above won't crack from excessive deflection.
Padstone Design
At each end of the beam, we specified a 300mm deep × 215mm wide concrete padstone (grade C30). The padstone spreads the beam's reaction (59.6 kN) over a sufficient area of brickwork so the bearing stress stays below the wall's capacity.
We've seen jobs where padstones were forgotten or undersized. Within months, the brickwork under the beam ends crushes and the beam drops. It's one of the most common — and most avoidable — mistakes in domestic steelwork.
Temporary Works
We included a temporary propping layout in our drawings:
- Position and spacing of Acrow props (2 rows, 1m centres)
- Spreader beams above and below the props
- Sequence: install props → remove wall → lift steel → pack and bed beam → wait 24 hours → remove props
This isn't a detail every structural engineer provides, but we include it as standard. It prevents the builder from improvising.
Building Control
We submitted the full package to Newham Building Control:
- Structural calculations (8 pages)
- General arrangement drawing showing beam position, padstones, and propping
- Connection detail sheet
Newham approved within 2 weeks — no queries. We've submitted to Newham many times and know how they like calculations presented: clear load paths, explicit reference to design codes, and labelled diagrams.
The Result
The builder completed the wall removal and beam installation in 2 days. The homeowner now has a 4.2m wide open-plan kitchen-diner — the full width of the house. The beam was boxed in with plasterboard, so it's invisible from below.
The builder's feedback: "Your propping detail was really helpful — I didn't need to phone up asking where to put the Acrows. And the padstone spec was spot on. Made the whole job easy."
Total Project Costs
| Item | Cost | |---|---| | Structural engineer (SBS) | £500 | | Builder (wall removal + beam + making good) | £2,800 | | Building Control fee | £400 | | Total | ~£3,700 |
For a project that completely transformed the ground floor of a 3-bed semi, £3,700 is excellent value.
Lessons from This Project
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4m+ spans need serious engineering. Don't let a builder "estimate" a beam size for a 4+ metre span. The loads are significant and getting it wrong risks structural failure.
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Padstones are non-negotiable. Every steel beam needs properly designed padstones. The £50 cost of a padstone prevents thousands of pounds of remedial work.
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Temporary works details save time. Including a propping layout in the structural drawings eliminates guesswork on site and makes the builder's job faster and safer.
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Local Building Control knowledge speeds approval. We know what Newham expect, so we format our submissions accordingly. Result: no queries, no delays.
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Fixed pricing beats hourly rates. Our £500 fee was quoted before we started. The homeowner knew exactly what the engineering would cost — no surprises.
Thinking about removing a wall? We offer free consultations across Stratford, Newham, East London and 70+ locations.
- Call: 07401 650600
- Email: sbs.structures@gmail.com
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