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

RSJ installation · Cornwall

RSJ installation in Cornwall

RSJ installation across Cornwall, designed by a structural engineer and signed off by building control.

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

Free survey in Cornwall

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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 Cornwall: 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.

Across Cornwall, RSJ installation usually comes up when people want more light, a better layout or a way through to a new extension. Coverage takes in St Austell, Redruth and Falmouth and everywhere in between. Whatever the reason, the beam is sized from calculations and the work is inspected before anything is covered.

Worth knowing before you start

  • 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.
  • 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.
  • Floor joists can rest on the bottom flange, hang from timber packers bolted into the web, or be notched to sit over the steel. The engineer specifies the connection, and it affects how flush the finished ceiling can be.
  • 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.
  • 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.

From survey to sign-off in Cornwall

  1. Survey in Cornwall

    We visit, look at the wall and what sits above it, measure the opening and note services, access and how the steel can be brought in.

  2. Engineer's design

    A structural engineer sizes the beam, padstones and any posts, and sets out the temporary support needed while the wall is out.

  3. Building control

    We submit a building notice or full plans application to the local council's building control team, so approval is in place before the wall is touched.

  4. Install and sign-off

    Props go in, the opening is formed, the steel is set and packed, building control inspects it, and we make good.

How much should I budget in Cornwall?

As a guide, budget £820–£2,580 per beam including VAT for rSJ supply and fit (single beam) in Cornwall, based on published UK cost guides adjusted for prices in the South West (+3%).

JobTypical guide rangeWhat it usually covers
RSJ supply and fit (single beam)£820–£2,580 per beamBeam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately)
Temporary works and propping£150–£520Props, spreaders, needles and sole plates for a typical opening, installed and struck
Steel goalpost frame£2,050–£6,200Two posts and a beam bolted as a frame, pad foundations, base plates and fitting
Structural calculations for a beam£260–£770Site measure or photos, beam and padstone design and calculations for building control

Figures include our approximate regional adjustment for prices in the South West (+3%) and are rounded. How these figures are worked out.

Approvals in Cornwall

Structural openings in English homes need building regulations approval before work starts. The local council's building control team can deal with it, or you can use a registered building control approver. Either way the steel is inspected before it is covered, and a completion certificate is issued at the end. Keep it safe for when you sell.

If the beam bears into a wall you share with a neighbour, the Party Wall etc. Act 1996 applies, and a party structure notice must be served at least two months before that work starts. We arrange this through a party wall surveyor.

Building rules in England

Local questions answered

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

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.

Which towns in Cornwall do you cover?

We cover towns including Redruth, Falmouth, St Austell and Truro, plus the villages and smaller towns around them.

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.

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.

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 I need building regulations approval to fit an RSJ?

Yes, when the RSJ carries structural load such as a wall, floor or roof. In England and Wales building control is notified or approved beforehand, Northern Ireland needs a council application before work starts, and Scotland requires a building warrant first. A completion certificate confirms sign-off at the end.

How much does RSJ installation cost in Cornwall?

As a guide, budget £820–£2,580 per beam including VAT for rSJ supply and fit (single beam) in Cornwall, based on published UK cost guides adjusted for prices in the South West (+3%). The exact figure depends on the span, what the wall carries, access and the finish, and is fixed in writing once the scope is agreed.

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.