An RSJ is the steel beam that carries the load once a wall or an opening is taken out. GS Renovation is a contractor. We appoint a structural engineer, build to the calculations issued, and coordinate the building control application and the inspections in Hatfield. For a beam alone on one straightforward opening, indicative costs run from £1,500 to £4,000 (indicative London ranges, MyBuilder and Checkatrade, 2026).
What building control looks at when the beam goes in
Hertfordshire Building Control names structural beams and openings as one of the items its inspectors examine on site. The visit is arranged while the steel, its bearings and its padstones are still open to view, before anything is boarded or plastered. We book it into the programme rather than after the fact, so nothing has to be opened up again.
Where a building notice is used, Hertfordshire Building Control states the work can commence within 48 hours of the council receiving the notice. That is the notice period, not the design period. The engineer's calculations still come first, because the beam size, the bearing length and the padstone specification all follow from them.
What sits under a new pier or pad
The British Geological Survey maps the bedrock beneath central Hatfield as Lewes Nodular Chalk Formation and Seaford Chalk Formation, undifferentiated. Ground only enters an RSJ job where the load has to travel below floor level, for example where an end bearing needs a new pier or a pad foundation. The engineer specifies what that support has to reach, and we build to it.
Beams in flats and blocks
An Article 4 Direction confirmed in June 2022 removes the permitted development right to build additional storeys onto existing blocks of flats in Hatfield. A block cannot gain a floor without planning permission, so internal alteration is the route left inside a flat. Work in a leasehold flat also needs the freeholder's consent under the lease, which is separate from anything the council decides.
- Structural openings for open-plan living
- Level, plumb and deflection checks before props are struck
- Steel columns, base plates and bolted connections
- Beam boxing, fire protection and plasterboard encasement
- Structural engineer's calculations arranged and followed
Trusted RSJ and Steel Beam Installation in Hatfield
We are a contractor, not a design practice. The structural engineer we appoint issues the calculations, we build the beam to them, and we coordinate the building control application and the site inspection. The beam is the part of your home that disappears behind plaster, so the inspection has to happen at the right moment rather than the convenient one. We are fully insured, you deal with one point of contact, and the quotation is free and carries no obligation.
- Clean, tidy and reliable tradespeople
- Building control inspected at the propping and beam stages
- Restricted London access planned before the steel arrives
- Party Wall Act notices served where a beam bears into a shared wall
- Site left safe and secure at the end of every day
- Waste cleared as we go, not left piled in the garden