Steel BeamInstallers
Two installers seen from behind lifting a steel beam onto a padstone

RSJ installation · Belfast

RSJ installation in Belfast

Calculations, approvals, propping, steel and making good for RSJ installation across Belfast.

  • Survey, design and installation in one
  • Covering BT1, BT10, BT11, BT12
  • Inspected before it is covered

Free survey in Belfast

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  • Free survey visit
  • Engineer's calculations arranged
  • Building control handled
  • Fixed written price once scope is agreed
  • England, Wales, mainland Scotland & NI

What RSJ installation involves in Belfast

RSJ installation is the supply and fitting of a structural steel beam to carry load across an opening or in place of a wall. RSJ stands for rolled steel joist, an older name for an I-shaped steel section; most domestic beams today are universal beams. Installation covers fabrication to the engineer's design, delivery, lifting, bedding on padstones and packing tight.

RSJ installation is one of the most common structural jobs in homes across Belfast. Towns we cover include Castlereagh, among other places in the area. Every job starts with a survey visit, then calculations from a structural engineer, so the steel suits the house in front of us rather than a rule of thumb.

Worth knowing before you start

  • 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.
  • 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.
  • If you already hold calculations from an architect or engineer, we install to those. Where something on site differs from the drawing, such as a weaker wall or a different joist direction, the engineer is asked to confirm before work carries on.
  • Heavy steels are raised with suitable lifting equipment rather than by hand alone. Manual handling is planned so nobody carries more than is safe, and the lift is coordinated so the beam goes up level onto both bearings together.
  • 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.

How the job runs in Belfast

  1. Look and measure

    We check the wall, the span you want and what the wall is carrying, and photograph anything the engineer needs to see.

  2. Design and price

    Calculations come back from the engineer and we confirm your fixed written price, line by line.

  3. Building control

    A full plans application or building notice goes to Belfast City Council under the Building Regulations (Northern Ireland) 2012 before work begins.

  4. Fit, inspect, finish

    The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.

How much should I budget in Belfast?

As a guide, budget £690–£2,150 per beam including VAT for rSJ supply and fit (single beam) in Belfast, based on published UK cost guides adjusted for prices in Northern Ireland (-14%).

JobTypical guide rangeWhat it usually covers
RSJ supply and fit (single beam)£690–£2,150 per beamBeam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately)
Steel beam replacement£1,700–£4,750Propping, removing the failed beam, new steel on proper bearings, approval and making good
Load-bearing wall removal with steel beam£1,700–£4,300Typical internal wall up to about 4 m: calculations, building control, propping, steel, padstones, fitting, fire protection and making good
Fire protection to a steel beam£130–£520 per beamFire-rated board boxing or an intumescent coating system as specified

Figures include our approximate regional adjustment for prices in Northern Ireland (-14%) and are rounded. How these figures are worked out.

Approvals in Belfast

In Northern Ireland, structural work comes under the Building Regulations (Northern Ireland) 2012 and is approved by the local council's building control. For Belfast that is Belfast City Council. We submit a full plans application or building notice before work starts and book the inspections.

The Party Wall etc. Act does not extend to Northern Ireland. Shared walls are dealt with under your title and the general law, so we recommend agreeing access and the work with your neighbour before it starts.

Building rules in Northern Ireland

RSJ installation by town

Questions about RSJ installation in Belfast

Can I stay at home while the work is done in Belfast?

Usually, yes. The work area is screened and floors are protected. The rooms either side of the opening are out of action for a few days, and there is some noise and dust while the masonry comes out.

Do I need a party wall agreement for RSJ installation in Belfast?

There is no Party Wall Act in Northern Ireland. Your title deeds and the general law apply instead, so agree the work with your neighbour in writing before it starts.

Does an RSJ need to be painted or boxed in?

Usually it needs fire protection, most often by boxing in with fire-rated plasterboard and skimming. If you want the steel on show, an intumescent paint system can be applied to the specified thickness and then top-coated in your chosen colour. The fabrication primer is not fire protection on its own.

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.

How is an RSJ installed?

The structure above is propped, the wall or opening is prepared, and padstones are bedded at each end. The beam is lifted onto them, bolted where needed and packed with shims and dry-pack. Props come out once it is carrying, building control inspects it, and the steel is then fire protected and finished.

Do you cover Belfast for RSJ installation?

Yes. We carry out RSJ installation in Belfast. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.

Planning to take a wall out?

Book a free survey visit. You get an itemised written quote covering calculations, building control, steel and making good.