How Much Does It Cost to Install an RSJ?
£800 – £3,000
per beam
Installing an RSJ steel beam costs between £800 and £3,000, depending on the size of the beam, the span of the opening, and the amount of structural propping and making-good required. RSJs are typically needed when removing a load-bearing wall to create an open-plan space, and a structural engineer must specify the correct beam size.
Average cost
£800 – £3,000
per beam
Prices vary by region, property type and tradesperson. Always get at least two quotes.
What affects the price?
Beam size and weight - a small 3m RSJ for a doorway opening costs £150-£400 for the steel; a large 5m+ beam for an open-plan knock-through costs £400-£1,200
Structural engineer fees - a structural engineer must calculate the beam size and issue calculations for building control, adding £300-£600
Temporary propping - while the beam is installed, the floor above must be supported with acrow props, adding labour time
Making good - plastering over the beam padding, reinstating the ceiling, and finishing the new opening adds to the total project cost
Labour vs materials
RSJ installation typically takes one to two days for a team of two. Labour makes up 50-60% of the total cost; the beam, padstones, and props account for the materials element.
Questions to ask your tradesperson
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