RSJ and Steel Beam Installation Eltham

GS Renovation installs RSJs and steel beams across Eltham, from the 1930s semi-detached houses off the main SE9 roads to the wider interwar homes near Eltham Park and Avery Hill. We open up load-bearing walls safely, sizing every beam through a structural engineer and clearing the work with building control.

In Eltham, a steel beam for one opening typically costs £1,500 to £4,000 fitted and signed off, or £2,500 to £6,500 or more for a full knock-through with the engineer's fee and making good (indicative London ranges, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Eltham.

How the job runs

1. Free site survey at your Eltham address and an itemised quote.
2. The engineer we appoint sizes the beam, and the work is registered with the Royal Borough of Greenwich building control or an approved inspector. On a shared wall you serve the party wall notice as building owner; we supply the drawings.
3. Props go in, the opening is cut and the beam is set on padstones, packed tight above.
4. Building control inspects the steel before it is covered. We make good, and the completion certificate follows.

Steel beams for Eltham interwar semis

The typical Eltham job removes the wall between the front and back reception rooms of a 1930s semi, creating one long, bright living space. That dividing wall almost always carries load from the floor and roof above, so we install a steel beam sized by a structural engineer rather than guessing. The beam bears onto concrete padstones at each end, spreading the weight down through the existing brickwork of the house.

Before any brick comes down, we set up temporary propping to hold the structure, then carry out staged demolition so nothing shifts unexpectedly. Working in an interwar suburban home on a generous SE9 plot gives us room to handle steel and materials without churning up the whole street. Every stage is inspected, and the finished opening is signed off by building control for your records.

Housing in Eltham

Eltham's housing, as the Council Tax list records it, is about 14,360 homes: 73% houses, 27% flats, with 17% pre-1919, 52% interwar and 30% built since 1945. Semi-detached houses make up 35% of homes here, and a beam bearing on the shared wall of a semi in Eltham means one party wall notice.

Timing the steel and the bearing inspection in Eltham

Royal Greenwich building control needs two days notice before any work under a building notice starts, and each site inspection has to be booked at least 2 working days before it happens. On an Eltham RSJ job those two rules set the order of the week. The notice goes in before the first prop is stood up, and the bearing inspection is booked on the day the steel delivery is confirmed, not on the day the beam is already up. Book it late and the opening sits propped and half finished, ends exposed, while the household steps round the props for longer than it needs to.

The bearings are what the inspector has come to see, and in a 1930s semi one of them can land in the wall shared with next door. We leave both ends open, with the packing visible and photographed, until that visit is over, and only then does the casing go on. If the inspector asks for a change, such as a longer bearing or different packing under the steel, it is a morning's work while the beam is bare. Once the steel is boarded and skimmed in an Eltham front room, the same request means cutting the finish back out and redecorating.

Party wall steelwork in shared Eltham houses

Many Eltham semis share a party wall with the neighbouring property, and chimney breasts and dividing walls often sit within it. When a steel beam bears onto or cuts into that shared wall, the Party Wall Act applies, and you must serve notice on the adjoining owner before work starts (or your surveyor does). We flag this at the survey stage so there are no surprises and the paperwork is in place well ahead of the build.

Removing a chimney breast on the ground floor to widen a room is common in these houses, but the stack above still needs supporting, usually on a steel beam, or gallows brackets where the engineer and building control accept them. We work with the structural engineer to specify the right solution for your SE9 property, prop safely during the works, and leave the opening ready for plastering and finishing throughout.

Checking the loft before touching the wall

The loft answers questions you cannot answer from downstairs. In an Eltham 1930s semi the roof is usually a cut timber structure with purlins carrying the rafters, and those purlins are often propped by struts that come down onto an internal wall. If that wall is the one you want out, the new beam is not simply carrying a floor, it is carrying part of the roof as well, and the load is significantly higher.

We also check whether the water tank sits over the wall line, whether the ceiling joists run the way we expect, and whether anything was altered when a previous owner boarded the loft out. All of it goes to the structural engineer with the survey, because a beam sized for a floor load and then asked to carry roof struts is the sort of error that shows up as a sagging ridge years afterwards. Ten minutes with a torch in the roof space at survey stage prevents that entirely.

• Lintel and catnic support to smaller openings
• Temporary propping and staged, controlled demolition
• Structural engineer's calculations arranged and followed

VOA Council Tax stock of properties, March 2025, for all 5 statistical areas in Eltham. Counts rounded by the VOA.

Plenty of Eltham projects start with one job and grow, so it helps to see home renovation in Eltham, RSJ and steel beam installation across Greenwich, building control sign-off for a steel beam, the Party Wall Act when a beam bears on a shared wall, RSJ and steel beam installation anywhere in London and Wall Tie Failure.

Why Eltham Homeowners Choose GS Renovation

Eltham homeowners choose GS Renovation because we treat steelwork as structural engineering, not guesswork. We coordinate the engineer's calculations, padstones, propping and building control sign-off, and give you the drawings for the party wall notice where the beam meets a shared wall. With our founder's 30+ years on the tools, we open up your home safely and leave it ready to finish.

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.