An RSJ for a wall removal does not have one fixed price, because two jobs that look identical from the kitchen can cost very different amounts once the structure is understood. The figure on your invoice is driven by the beam your structural engineer specifies and the work needed to get it safely in place. Below are the real cost drivers, so you know what you are paying for before you ask for a quote.
The single biggest driver: the beam your engineer specifies
You cannot price an RSJ until a structural engineer has calculated it. The engineer works out the load above the opening and specifies the beam section (its depth and weight per metre) and the length. A heavier, deeper section for a wide span or a load-bearing wall under more floors costs more in steel than a light beam over a small opening. This is also why a quote given before the calculation exists is a guess, not a price. For load-bearing work this calculation and Building Control sign-off are not optional.
Span and opening size
The width of the opening drives both the steel and the labour. A wider span needs a stronger (and heavier) beam, and a longer beam is harder to handle and lift into position. Knocking two rooms into one across a 4 metre opening is a bigger job than a 2 metre doorway, even before access is considered.
Single beam or multiple
A straightforward single RSJ over one opening is the simplest case. Removing a corner, supporting a structure above on two sides, or spanning where one beam cannot do the job may call for two or more beams, goalpost frames, or columns. More steel and more connections mean more cost. Your engineer decides this, not the builder.
Padstones, bearings and connections
The beam has to land on something that can carry the load. That usually means padstones (concrete or engineered bearing blocks) built into the existing walls, and sometimes new piers or columns. Cutting pockets, building sound bearings and making the connections is skilled work and a real line in the cost.
Temporary propping and support
Before the wall comes out, the structure above has to be held up with temporary props (often Acrow props on needles or strongboys). Propping a single-storey opening is quick. Propping under two floors, a chimney breast or a wider span takes more equipment and time, and that labour is part of the fit cost.
Site access
Access often surprises people. Getting a long steel beam into a mid-terrace with no rear access, or up to a first-floor opening, is far harder than carrying it into a detached house with a wide side passage. Ground floor versus upper floor, terraced versus detached, and how much can be lifted by hand all change the labour.
Making good
Once the beam is in, the opening has to be finished: closing up around the bearings, plastering, boxing or fire-protecting the steel where required, and tidying floors and skirting. How much making good you want included (bare structural finish versus ready to decorate) changes the quote.
Supply only versus supply and fit
Splitting the cost helps you compare quotes honestly. Supply only is the steel itself, cut and drilled to the engineer’s specification. Supply and fit adds everything above: propping, lifting, bearings, connections and making good. The steel is frequently the smaller part of the total, which is why a per-metre steel price tells you very little about the finished cost. At TC Rowan we can do either, with our own Banbury workshop and erection team handling the job from drawing to final bolt.
A rough guide (not a quote)
As a rough guide only, and assuming a single modest beam, easy access and standard making good, a homeowner supply-and-fit RSJ project commonly runs into the low thousands of pounds once labour, propping and finishing are included. Wider spans, multiple beams, awkward access or upper floors push it higher. Treat that as orientation, not a price: every job differs, and the only honest number comes from a calculation and a site look. Steel prices also move with the market.
The fees that sit alongside the steel
Two professional costs are separate from your supply-and-fit price and easy to forget when budgeting:
- Structural engineer’s calculation to size the beam and produce the specification.
- Building Control approval and inspection for the load-bearing work.
A builder or architect managing the wider project may add their own fee. None of these are part of the steel price, so factor them in early. For the structural design and frame side of larger projects, see our structural steelwork service.
Frequently asked questions
How much does it cost to install an RSJ in the UK?
There is no single figure. The cost depends on the beam section your structural engineer specifies, the span of the opening, propping, padstones and making good. Ask for a supply-and-fit quote rather than a per-metre guess, and budget separately for the engineer’s calculation and Building Control.
Why does the steel cost less than the installation?
The raw steel is often the smaller part of the bill. Most of the cost is labour: temporary propping, cutting the opening, lifting the beam into place, building bearings and padstones, then making good. A short beam in an awkward terraced house can cost more to fit than a longer beam with easy access.
What extra professional fees come on top of the RSJ?
Two usually apply. A structural engineer must calculate the beam size and produce a specification, and load-bearing work needs Building Control approval with an inspection. Some homeowners also pay a builder or architect to manage the job. These are separate from the supply-and-fit price.
Can I get an RSJ supplied only and fit it myself?
We can supply steel cut and drilled to an engineer’s specification, but fitting a load-bearing beam is structural work that needs propping and Building Control sign-off. Most homeowners use a builder or our own erection team. Tell us your situation and we will price supply-only or supply-and-fit. For the sections involved, see our universal beam sizes chart, or get a free quote.