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

RSJ installation · Lisburn and Castlereagh

RSJ installation in Lisburn and Castlereagh

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

  • Price fixed in writing once scope is agreed
  • Building control arranged
  • Temporary works and making good included

Free survey in Lisburn and Castlereagh

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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 Lisburn and Castlereagh

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.

Across Lisburn and Castlereagh, RSJ installation usually comes up when people want more light, a better layout or a way through to a new extension. We can survey in places such as Lisburn and the villages around them. Whatever the reason, the beam is sized from calculations and the work is inspected before anything is covered.

Key points for your project

  • Packing is what makes the beam work. Steel shims and dry-pack mortar fill the gap between the top flange and the structure above, so the load transfers onto the steel without the floor or wall settling down onto it.
  • Delivery can make or break an RSJ job. A long beam has to turn through a front door, along a hallway and past the stairs, so routes are measured at the survey and alternatives such as a window opening are planned early.
  • 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.
  • Sometimes two beams are bolted side by side with spacers, either to carry a thick wall or to fit through a tight space. Bolt spacing and spacer type come from the engineer's design rather than being decided on site.
  • 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.

What happens, step by step

  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 Lisburn and Castlereagh 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.

Guide prices for RSJ installation in Lisburn and Castlereagh

As a guide, budget £690–£2,150 per beam including VAT for rSJ supply and fit (single beam) in Lisburn and Castlereagh, 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)
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
Structural calculations for a beam£220–£640Site measure or photos, beam and padstone design and calculations for building control
Temporary works and propping£130–£430Props, spreaders, needles and sole plates for a typical opening, installed and struck

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

Building control and neighbours in Lisburn and Castlereagh

Building control in Lisburn and Castlereagh is run by Lisburn and Castlereagh City Council. Beams and new openings are controlled work under the Northern Ireland regulations, so we apply before anything is removed and the steel is inspected before it is covered.

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 Lisburn and Castlereagh

Can you work on older or listed homes in Lisburn and Castlereagh?

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.

Do I need a party wall agreement for RSJ installation in Lisburn and Castlereagh?

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.

What is included in an RSJ supply and fit price?

Our itemised written quote sets out the calculations, building control, steel and fabrication, delivery, lifting, padstones, propping, labour, fire protection and making good as separate lines. Once the specification and scope are agreed, the price is fixed in writing, so you know the full cost before work starts.

Can you fit an RSJ to my own engineer's calculations?

Yes. We install to calculations and drawings from your engineer or architect, as long as they cover the beam, bearings and any columns or connections. If site conditions differ from what the design assumed, we check with the engineer before carrying on.

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.

Is an RSJ the same as a steel beam?

In everyday use, yes. Builders and homeowners call most steel beams RSJs, whether they are universal beams, channels or columns. Technically an RSJ is one particular older section shape, but the engineer's drawing names the exact section type, so there is no confusion on site.

Do you cover Lisburn and Castlereagh for RSJ installation?

Yes. We carry out RSJ installation in Lisburn and Castlereagh. 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.