Steel Beams for Extensions & Loft Conversions
RSJs and structural steel for home extensions, loft conversions and knock-throughs - calculated, supplied and fitted.
Opening up a kitchen, building an extension or converting a loft almost always means steel. We supply and fit the RSJs, beams and posts that carry the load once a wall or roof is altered, so the work is safe and signed off.
Give us your structural engineer's calculations, or we can arrange them, and we will fabricate the steel to suit - cut to length, drilled, with padstones and fixings as needed. We can deliver for your builder or install ourselves.
Where steel is needed in home projects
- Knock-throughs — taking out a load-bearing wall between rooms, often with a goalpost frame where the walls either side can't take the load.
- Rear and side extensions — a beam over the opening where the old back wall comes out, and often posts and beams to carry the new roof.
- Loft conversions — steel beams to carry the new floor, support the roof where purlins or struts are removed, and frame a dormer.
- Chimney breast removal — beams or brackets to support what's left above. See removing a chimney breast.
- Bi-fold and sliding door openings — wide openings in a back wall, sometimes with cranked beams to follow the roof.
What you'll need
- Calculations — a structural engineer sizes the steel and its supports. See what size steel beam do I need.
- Building regulations approval — building control checks the calculations and inspects the work. See do I need building regs for a steel beam.
- The steel — cut, drilled and prepared to the calculations, with bolted joints if long beams need to come into the house in pieces.
- Padstones and fixings — padstones spread the load into the walls, with bolts, packers and end plates as specified.
- Fire protection — usually fire-rated plasterboard or intumescent paint once the steel is in.
Supply only, or supply and fit
Many builders just want the steel, made right and delivered on time. Others would rather we fit it too. We do both. Our fitting team props the structure, removes the wall, installs the steel on its padstones and packs it tight, ready for building control to inspect.
Every beam is fabricated in our Peterlee workshop to UKAS-approved EN1090-1 Execution Level 3 and marked so it goes in the right place. Our steel beam marking guide explains the labels.
Reliable lead times and steel that is right first time keep your project moving.
Frequently asked questions
How much does a steel beam for an extension cost? It depends on the size and length of the steel, the work done to it and whether we fit it. Our steel beam cost guide explains the main factors.
How quickly can you make it? Once the calculations are approved, most domestic steel is made quickly. See how long does a steel beam take.
Can a long beam get into my house? Usually, yes. Long beams can be made in sections with bolted splice joints and joined in place.
Do I need a structural engineer? Almost always. See do I need a structural engineer for a steel beam, or send us your plans and we'll help.