
RSJ installation · Colwyn Bay
RSJ installation in Colwyn Bay
RSJ installation for homes in LL28, LL29, designed by a structural engineer.
- Survey, design and installation in one
- Covering LL28, LL29
- Inspected before it is covered
- 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 Colwyn Bay
Our RSJ installation service in Colwyn Bay covers everything from the first visit to the completion paperwork. We also cover the surrounding towns and villages in Conwy. Postcode districts we cover here include LL28 and LL29.
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.
Things to plan for
- 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.
- 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.
- 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.
- 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.
- 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.
Four stages, one team
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.
Design and price
Calculations come back from the engineer and we confirm your fixed written price, line by line.
Building control
We submit the application or notice to Conwy County Borough Council under the Building Regulations as they apply in Wales, before work starts.
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 Colwyn Bay?
As a guide, budget £730–£2,280 per beam including VAT for rSJ supply and fit (single beam) in Colwyn Bay, 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) |
| Fire protection to a steel beam | £140–£550 per beam | Fire-rated board boxing or an intumescent coating system as specified |
| Structural calculations for a beam | £230–£680 | Site measure or photos, beam and padstone design and calculations for building control |
| Steel goalpost frame | £1,800–£5,450 | Two 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 Colwyn Bay
Welsh building regulations treat beams and new openings as controlled building work. We apply to Conwy County Borough 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.
The Party Wall etc. Act 1996 applies in Wales as well as England, so a beam bearing into a shared wall needs a party structure notice at least two months before work starts. We arrange notices through a party wall surveyor.
Local questions answered
How soon can RSJ installation start in Colwyn Bay?
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.
Can you work on older or listed homes in Colwyn Bay?
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.
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.
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.
Who approves RSJ installation in Colwyn Bay?
Structural work in Colwyn Bay needs a building control application to Conwy County Borough 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.