RSJ installation · Gwynedd
RSJ installation in Gwynedd
RSJ installation across Gwynedd, designed by a structural engineer and signed off by building control.
- Price fixed in writing once scope is agreed
- Building control arranged
- Temporary works and making good included
- 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 Gwynedd
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 in Gwynedd follows the same careful process wherever the property is: a survey, an engineer's design, the right approval and safe temporary works. That includes Bangor, Porthmadog and Dolgellau, plus smaller towns and villages nearby. We price it all up front so there are no surprises once the wall is open.
Worth knowing before you start
- 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.
- 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.
- 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.
- 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.
What happens, step by step
Free visit
A short visit to Gwynedd to see the job, agree what you want and check the bearings, floors and services that affect the design.
Calculations
The engineer's calculations and a simple drawing are prepared for your opening and shared with you before anything is ordered.
Building control
We submit the application or notice to Cyngor Gwynedd under the Building Regulations as they apply in Wales, before work starts.
Steel in, made good
On site we prop, open up, fit and pack the steel, then fire protect, box in and plaster once the inspection is done.
What does RSJ installation cost in Gwynedd?
As a guide, budget £730–£2,280 per beam including VAT for rSJ supply and fit (single beam) in Gwynedd, based on published UK cost guides adjusted for prices in Wales (-9%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| RSJ supply and fit (single beam) | £730–£2,280 per beam | Beam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately) |
| Steel goalpost frame | £1,800–£5,450 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
| Load-bearing wall removal with steel beam | £1,800–£4,550 | Typical 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 | £140–£550 per beam | Fire-rated board boxing or an intumescent coating system as specified |
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 Gwynedd
In Wales, structural alterations come under the Building Regulations 2010 as they apply in Wales. Cyngor Gwynedd handles building control for Gwynedd. For work started or approved from 1 July 2026, the Welsh system uses an application to building control, dutyholders appointed in writing, a commencement notice before work starts and a compliance statement at the end.
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.
RSJ installation by town
Questions about RSJ installation in Gwynedd
What happens at the survey visit in Gwynedd?
We look at the wall, the floor and ceiling either side and what sits above, measure the opening you want, and note cables, pipes and access for the steel. It usually takes under an hour and there is no charge.
Who approves RSJ installation in Gwynedd?
Structural work in Gwynedd needs a building control application to Cyngor Gwynedd 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.
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.
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 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.
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.
Do I need a party wall agreement for RSJ installation in Gwynedd?
Yes, if the beam bears into a shared wall: the Party Wall etc. Act 1996 applies in England and Wales, and a party structure notice must be served at least two months before that work starts. We arrange it through a party wall surveyor.