
RSJ installation · Isleworth
RSJ installation in Isleworth
Steelwork, approvals and making good for RSJ installation in Isleworth and nearby.
- Free survey visit in Isleworth
- Engineer's calculations arranged
- Building control handled for you
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
About our RSJ installation service in Isleworth
Our RSJ installation service in Isleworth covers everything from the first visit to the completion paperwork. Our coverage runs across London, so nearby villages are included too. Postcode districts we cover here include TW1, TW2, TW3, TW4 and TW5.
People still call almost any steel beam in a house an RSJ, even though the sections fitted today are usually universal beams with parallel flanges. Whatever the name, the job is the same: a length of structural steel, made to an engineer's specification, carrying floors, walls or roof over a space where support used to be.
Key points for your project
- Floor joists can rest on the bottom flange, hang from timber packers bolted into the web, or be notched to sit over the steel. The engineer specifies the connection, and it affects how flush the finished ceiling can be.
- RSJ originally meant a rolled steel joist with tapered flanges. Most beams supplied for homes today are universal beams with parallel flanges, but the term RSJ has stuck, and builders, engineers and building control all understand what it means.
- The engineer chooses the section type for the job. Universal beams suit most spans, universal columns are stockier and used as posts or where depth is limited, parallel flange channels fit against walls or timbers, and box sections suit slim or exposed members.
- Padstones spread the concentrated load from each beam end into the masonry below. They may be concrete, engineering brick or a steel plate, depending on the engineer's design and the strength of the wall beneath.
- Structural steel comes in recognised grades, and the engineer's drawing states which grade the calculations assume. The steel supplied matches that specification, and the delivery paperwork is kept so building control can see what has been fitted.
How the job runs in Isleworth
Survey in Isleworth
We visit, look at the wall and what sits above it, measure the opening and note services, access and how the steel can be brought in.
Engineer's design
A structural engineer sizes the beam, padstones and any posts, and sets out the temporary support needed while the wall is out.
Building control
We submit a building notice or full plans application to the local council's building control team, so approval is in place before the wall is touched.
Install and sign-off
Props go in, the opening is formed, the steel is set and packed, building control inspects it, and we make good.
What does RSJ installation cost in Isleworth?
As a guide, budget £1,000–£3,200 per beam including VAT for rSJ supply and fit (single beam) in Isleworth, based on published UK cost guides adjusted for London prices (+28%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| RSJ supply and fit (single beam) | £1,000–£3,200 per beam | Beam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately) |
| Temporary works and propping | £190–£640 | Props, spreaders, needles and sole plates for a typical opening, installed and struck |
| Fire protection to a steel beam | £190–£770 per beam | Fire-rated board boxing or an intumescent coating system as specified |
| Load-bearing wall removal with steel beam | £2,550–£6,400 | Typical internal wall up to about 4 m: calculations, building control, propping, steel, padstones, fitting, fire protection and making good |
Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.
Approvals in Isleworth
Structural openings in English homes need building regulations approval before work starts. The local council's building control team can deal with it, or you can use a registered building control approver. Either way the steel is inspected before it is covered, and a completion certificate is issued at the end. Keep it safe for when you sell.
Terraced and semi-detached homes often need party wall notices, because cutting into a shared wall to take a beam end is notifiable under the Party Wall etc. Act 1996. Allow at least two months for the notice period unless your neighbour agrees sooner.
Questions about RSJ installation in Isleworth
Do you cover Isleworth for RSJ installation?
Yes. We carry out RSJ installation in Isleworth and the TW1, TW2, TW3, TW4 and TW5 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.
How soon can RSJ installation start in Isleworth?
Start dates depend on the engineer's calculations, the building control approval and, where needed, party wall notice periods. We give you a realistic timetable after the survey and keep you updated as each approval comes through.
Who decides what size RSJ I need?
A structural engineer. The size depends on the span, the loads from floors, walls and roof above, how stiff the beam needs to be and how its ends are supported. We arrange calculations from a qualified engineer, or fit to calculations you already have, rather than guessing a size.
Can an RSJ be delivered in sections?
Yes, where access is tight. The engineer can design bolted splice joints so a long beam arrives in two or more pieces and is joined in place. The splice has to be part of the calculations from the start, because it changes how the beam carries load at that point.
What does RSJ stand for?
RSJ stands for rolled steel joist. It was the name for a hot-rolled I-shaped steel section with tapered flanges, and it is still used loosely for any steel beam in a house. Most steels fitted in homes today are universal beams, which do the same job with parallel flanges.
Can you work on older or listed homes in Isleworth?
Yes. Older homes often have lime mortar, timber lintels or shallow footings, which the engineer allows for. Listed buildings need listed building consent for internal structural changes as well as building regulations approval, and that must be in place first.