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

RSJ installation · Pembrokeshire

RSJ installation in Pembrokeshire

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

  • Free survey visit in Pembrokeshire
  • Engineer's calculations arranged
  • Building control handled for you

Free survey in Pembrokeshire

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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

RSJ installation in Pembrokeshire: how it works

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.

Looking for RSJ installation in Pembrokeshire? Towns we cover include Pembroke Dock, Haverfordwest and Milford Haven, among other places in the area. Our teams handle the calculations, the building control approval, the propping and the steel itself, and leave the opening ready for plastering and decoration.

What to expect

  • 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.
  • 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.
  • Steel for internal use is normally delivered with a primer coat to protect it during installation. Beams in damp positions, within external walls or exposed outside need a more robust coating or galvanising, as the engineer specifies.
  • Where a long beam cannot be carried into a property in one piece, the engineer can design a bolted splice so it arrives in two or more lengths. The splice position and bolts are part of the calculations and must be installed exactly as drawn.
  • An RSJ inside a home commonly needs 30-minute fire resistance where it supports elements of structure. Fire-rated plasterboard boxing is the usual method, with intumescent paint used when the beam is to remain visible.

Four stages, one team

  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

    We submit the application or notice to Pembrokeshire County Council under the Building Regulations as they apply in Wales, before work starts.

  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.

What does RSJ installation cost in Pembrokeshire?

As a guide, budget £730–£2,280 per beam including VAT for rSJ supply and fit (single beam) in Pembrokeshire, based on published UK cost guides adjusted for prices in Wales (-9%).

JobTypical guide rangeWhat it usually covers
RSJ supply and fit (single beam)£730–£2,280 per beamBeam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately)
Structural calculations for a beam£230–£680Site measure or photos, beam and padstone design and calculations for building control
Steel beam replacement£1,800–£5,000Propping, removing the failed beam, new steel on proper bearings, approval and making good
Steel goalpost frame£1,800–£5,450Two posts and a beam bolted as a frame, pad foundations, base plates and fitting

Figures include our approximate regional adjustment for prices in Wales (-9%) and are rounded. How these figures are worked out.

Building control and neighbours in Pembrokeshire

Welsh building regulations treat beams and new openings as controlled building work. We apply to Pembrokeshire County Council on your behalf before anything is removed, give the commencement notice the 2026 Welsh rules require, and the steel is checked before it is boxed in.

Where the steel bears into a wall shared with next door, notice must be served under the Party Wall etc. Act 1996. If your neighbour dissents, surveyors agree how the work is done before it starts.

Building rules in Wales

RSJ installation in Pembrokeshire: your questions

Who approves RSJ installation in Pembrokeshire?

Structural work in Pembrokeshire needs a building control application to Pembrokeshire County Council under the Welsh regulations, with a commencement notice before work starts. We prepare and submit it with the structural engineer's calculations and arrange the inspections, so the completion paperwork follows the job.

Can you work on older or listed homes in Pembrokeshire?

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.

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.

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.

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.

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.

How soon can RSJ installation start in Pembrokeshire?

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.

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.