How Much is an RSJ?

DIY enthusiasts may be able to install an RSJ, but the calculations required to determine the amount of support required are complex.

Building codes require that joists be affixed to a wall that will support the weight of any building affixed to the joist.

There are some important things to consider...

It must be supported by a solid concrete block for the weight to be distributed evenly.

A structural engineer's calculations should be included in any quote for installing an RSJ.

The cost of installing an RSJ depends on the size of the beam, your specific property, if utilities need to be relocated, and where you are in the United Kingdom. An RSJ installation will typically cost between £1,500 and £2,500.

This includes the expense of hiring a structural engineer, plastering, skip hire, building control approval fees, materials, and installation labour.

Why you will find this guide useful...

This article will cover the different supply costs of an RSJ, how much it costs to install, and other additional information that you will need to know when having an RSJ installation.

Therefore, if you want to have an RSJ installed in your home, this article will give you all the information you need to know.

RSJ installation

Steel Beam Prices 2024

Job RSJ Length Timescale Material Cost Labour Prices
External Single Doorway 1 Metre 1-1.5 Days £200-£300 £400-£450
External Window Opening 2 Metres 1.5-2 Days £350 £600
Bifold doors 3 Metres 2 Days £400 £650-£700
House Extension 4 Metres 2-3 Days £500 £800
Loft Conversion 5 Metres 3 Days £700 £850-£950
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What is an RSJ?

Load-bearing and non-load-bearing walls are constructed when a house is constructed. The difference is that load-bearing walls support the entire building's structural weight, whereas non-load bearing walls exist solely to separate rooms.

If you wish to make an open-plan space by removing or changing a load-bearing wall, you'll need to add a steel RSJ beam to absorb the weight, or your house will fall because it won't have the necessary supports.

Correctly installing an RSJ involves careful calculations, time, and skill. An experienced builder or structural engineer will need to assess your site and run steel beam calculations to determine the sort of wall they're dealing with, the length of beam they'll require, and the amount of weight the beam will sustain.

Correctly installing an RSJ involves careful calculations, time, and skill. An experienced builder or structural engineer will need to assess your site and run steel beam calculations to determine the sort of wall they're dealing with, the length of beam they'll require, and the amount of weight the beam will sustain.

This then affects the price you need to pay to have an RSJ installed in your home.

Rsj home installation

Breakdown of The Costs

Steel supports, such as universal beams, are commonly used in construction. They're sturdy, simple to construct, and inexpensive to install. They are available in a variety of conventional lengths to suit practically any purpose.

However, the length isn't the only factor to consider. As the length rises, RSJ calculations are also used by mechanical engineers to increase the size of the cross-sectional profile. This means that when the RSJ grows longer, it will not bend more than the safety restrictions allow.

As a result, the price of a steel 'I Beam' rises as its profile and length grow. Furthermore, the greater the amount of steel used in manufacturing the universal beam, the heavier it becomes.

If it's heavy, it'll be more difficult to lift and will necessitate the use of mechanical lifting equipment. As a result, labour costs rise, and the cost of an RSJ installation rises as well.

The cost of installing an RSJ depends on the size of the beam, your specific property, if utilities need to be relocated, and where you are in the United Kingdom. An RSJ installation will typically cost between £1,500 - £2,500.

This includes the expense of hiring a structural engineer, plastering, skip hire, building control approval fees, materials, and installation labour.

We'll break down the installation costs in the table below using typical situations to demonstrate steel beam prices as well as labour costs. You can also use the statistics as an RSJ cost calculator to compare your results to your own.

A professional builder's experience and understanding are required for the installation of a rolled steel joist. You may be given an estimate for the entire job, but a tradesperson typically charges between £150 and £200 each day.

The task will necessitate at least two persons, with a labourer adding £80-£100 per day to the overall cost.

For the services of a structural engineer, expect to spend between £90-£200 per hour, with the higher fee most likely to be relevant in London and the southeast. Therefore, depending on where you are based could affect the price of installing an RSJ.

What are the Supply Costs of an RSJ?

If you're just interested in the price of only an RSJ, you might want to find out how much a steel beam RSJ costs per metre. RSJ costs between £50 and £100 per metre; however, depending on which one you are looking for will affect the price.

You can buy an RSJ as a supply alone, but it is not suggested that you install it DIY. Only a specialist can offer the right calculations on how much weight can be spread throughout your RSJ. The calculations involved with establishing an RSJ are complex, and a professional is always recommended to install an RSJ.

Rolled steel joist

The table below shows the supply-only expenses for various items that you could need for an RSJ project.

Type of Supply Cost Per Metre
Universal Beams £50-£120
Universal Columns £50-£120
Double Beams £50-£100
Parallel Flange Channel £30-£100
T-Beam £8-£20
Lintels £16-£22
Special Lintels £40-£60

What are the Additional Costs of Installing an RSJ?

Multiple additional factors are needed when installing an RSJ as it is known to be a messy job.

Therefore, depending on how the job goes, in some cases, additional tradespeople are needed to complete the job. Below are the additional costs that you should expect when installing an RSJ.

Additional Job Cost
Wall Demolition £1,000-£2,500
Skip Hire £200-£250 per week
Re-Decorating £150-£160 Per day
Re-Plastering £390-£510

Wall Demolition

Unless you're working on a new home or an addition, you'll almost certainly be removing a wall while installing an RSJ. Barriers between the kitchen, dining room, living room, and external walls for conservatories are normally removed.

The cost of removing the wall ranges from £1,000 to £2,500, with the cost of installing suitable supports ranging from £800 to £950.

Wall demolition

Before removing a wall, get it inspected by a builder or structural engineer to see if there are any electrical or plumbing problems, as well as whether the wall is load-bearing. Engineers and builders often charge around £200 for each visit.

The cost of removing a load-bearing wall is determined by the size of the task and the quality of the contractor you hire. A single doorway sized space (about 1m), a double doorway sized room (approximately 2m), and a bigger open plan space (approximately 4m) can cost around £1,750.

Skip Hire

When installing an RSJ, waste materials are bound to collect and build up, creating a mess. Taking a few bags of trash to the dump may be simple enough for little jobs, but it is just not a practical choice while larger operations are underway. It may be required to hire a skip in certain situations.

So, how much does skip hire cost?

Prices for skip hire might fluctuate due to a variety of factors. The size of a skip hire varies due to the size of the skip. Therefore, the bigger the skip is, the more it will cost to hire. Below is a table showing the price of the skip hires.

Size of the Skip Cost
Mini 2-3 Yard Skip £60-£120
Mini 4-5 Yard Skip £100-£260
Builder 6-8 Yard Skip £150-£375

The other factor that may influence the price of skip hire is where you live or the location of the job.

If you want to hire a skip in the North, for example, the pricing will likely be substantially different from those in London as working prices are different in these area's so tradesmen and the supplies will be more if you live somewhere like London.


If you're thinking of doing some internal renovations, you will need to consider various costs. Internal remodelling projects typically cost between £100 and £150 per sqm; however, this varies depending on the kind and scale of the project.


After you've installed an RSJ, you'll need to include it at the expense of painting and decorating. This could entail having your walls painted, which can cost anywhere from £180 to £500 depending on the size of the room.

If you choose wallpaper instead, you can expect to pay roughly £180 for a small room and up to £600 for a larger room.


Sometimes, when installing an RSJ, the walls can get damaged, which means you might have to hire a plasterer to re-plaster any walls that need re-doing.

The following is a cost breakdown of common plastering jobs. We consider the cost of re-plastering existing plaster to a thickness of 3mm, as well as the time it takes to finish the job, as some plasterers charge by the day, which could affect your price.

Size Price Timescale
Re-Plaster Small Room £400-£500 1 Day
Re-Plaster Medium Room £500-£700 1-2 Days
Re-Plaster Large Room £700-£1,200 2-3 Days

Tradesmen Costs for Installing an RSJ

Before you acquire an estimate for an RSJ installation, keep in mind that a structural engineer's expert calculations are required as part of the process.

You'll also need a professional builder to do the work according to the engineer's specifications. As previously said, no matter how careful the builders are, this type of labour will always result in a tremendous mess.

This mess will necessitate not just extensive cleaning but also re-plastering and re-decorating, all of which will add to the expense.

RSJ labour cost

Most of the work can be done by a competent local builder, but depending on where the RSJ is located, you may also require a structural engineer, as well as an electrician and a plumber.

Many people do their own final decorating, but others will require the services of a painter and decorator.

The cost of labour to install an RSJ is determined by the size of the job. Labour for a single doorway 1m RSJ cost between £400 and £450, a double doorway 2m RSJ costs between £550 and £600, and a big open plan 4m RSJ costs between £700 and £800.

Size Labour Cost
1 Metre Single Doorway £400-£500
2 Metre Double Doorway £550-£600
4 Metre £700-£800

How Long Does It Take to Install an RSJ?

The timescale to install an RSJ can vary depending on the size and how heavy the RSJ is. The planning can also be a long process as everything has to be perfect before the installation, as it is such an important job.

Due to this, here we will discuss the process and the timescales of installing an RSJ.

If a wall must be removed before installing an RSJ, it must be done by an expert. It cannot be done DIY. The removal process is simple if done carefully and steadily, but protection should always come first, and preparation is crucial to avoid damage or injury.

A structural engineer should be consulted in person, with the engineer coming to the job site to inspect the structure and provide relevant calculations and advice. This step is critical, and you should set aside one day to complete it and examine the information provided.

A load-bearing wall can be removed in a day by a team of two or three persons, depending on the size of the property. The removal process should be organised safely and sensibly, with rubble being collected as it is formed from the destroyed wall.

This decreases the quantity of waste to deal with while also making the work environment safer and more visible.

If enough people are on hand to perform it securely and correctly, installing the RSJ beam should take an hour or two. Padstones are inserted in the cavities where the RSJ will be installed to support it and raise it to the proper height to sustain the ceiling joists' weight.

RSJ timescales

The steel RSJ should be guided into position by a team of two to four individuals. It's critical to get the beam as close to its final location as feasible before installing the steel prop supports beneath the ceiling, as they will obstruct access to the installation site once they're in place.

This mentioned issue could be a costly mistake not just in terms of labour costs but also in terms of time. It will assist to finish the work in a timely, practical, and safe manner if everyone engaged understands the procedure to be utilised for installing the RSJ and talks things over before lifting anything.

There will need to be an electrician or plumber at present to decommission and make safe any wires or pipes that are being removed from the wall.

If the presence of any live services was previously undetected and no arrangement was made for the required tradesperson to be on-site to deal with it, this can cause the installation to be delayed. You may then have to wait for a tradesperson to become available.

As a result, removing the wall and installing the RSJ takes one to two days, depending on the size of the wall. Allow four to eight hours for plastering, depending on the size of the area that needs plastering, and half a day for painting or decorating, depending on the size of the area that needs painting or decorating.

As a result, after waiting for engineers and other tradespeople, installing an RSJ and finishing the job can take up to a week.

Job Timescale
Preparing 1 Day
Installing RSJ 1-2 Hours
Removing a Wall 1-2 Days
Plastering 4-8 Hours
Re-Decorating Half a Day

Types of RSJ

For usage in steel construction, RSJs come in a variety of shapes and sizes. Different steel members are made in factories based on the shapes, sizes, and qualities of these rolled steel sections. RSJs are made without joints in continuous casting moulds. The many varieties of RSJ are listed below.

I-Beam Cost

An I-Beam, also known as a H-beam or a universal beam, comprises two horizontal flanges and one vertical web. The web can withstand shear stresses, whereas the horizontal flanges can withstand most of the beam's bending action.

In the plane of the web, the I-shape is highly effective at carrying shear and bending loads. I-beams come in a variety of diameters and are commonly used in the building industry. They cost around £35-£115 per metre.



  • It comes in a variety of sizes
  • Good for corners


  • Not used for houses most of the time
  • Expensive in big bulks

Rolled Steel Channel Cost

The cross-section of structural C channels, also known as C beams, is C-shaped. The top and bottom flanges of a channel are connected by a web. C-shaped beams are a cost-effective alternative for structures with small to medium spans.

Originally intended for bridges, channel beams are now widely used in marine piers and other construction projects. This steel beam costs £10-£45 per metre.


  • Cheaper option
  • Popular steel beam


  • Only used for small/medium-sized houses

American Standard Beam Cost

The American standard beam, often known as an S-beam, consists of a rolled section with two parallel flanges joined by a web. S-shaped beams have relatively small flanges.

The identification of the beam determines the breadth and weight of each unit. S12x50, for example, denotes a 12-inch-deep beam weighing 50 pounds per foot. It costs around £40-£300.

American standard beam


  • Variety of sizes


  • More tradespeople are needed because of their weight
  • Mostly small sizes

Angled L-Shape Cost

Angle beams have two legs that meet at a 90-degree angle, forming an L shape. Angle beams are available with either equal or different leg diameters. For example, in an uneven leg L-beam, one leg could be 2x2x0.5 and the other 6x3x0.5.

Because of their shallow structural depth, L-beams are commonly employed in floor systems. This type of beam costs around £70-£150.


  • Legs can be of different sizes to fit the building better


  • Only really used on floor systems, so they are more expensive

Bearing Pile H-Shape Cost

When a project can't be built on a shallow foundation, builders use bearing piles to create a deep foundation system. To properly transport weights through the pile to the tip, bearing heaps are H-shaped.

Bearing piles are most effective in deep soils with high resistance at the tip. Individual piles can withstand weights of over 1,000 tonnes. The cost of this steel beam is £30-£95 per metre.

Bearing pile h-shape RSJ


  • Good as the final solution


  • Very heavy so needs more tradespeople to complete the job

Pipe Beam Cost

Structural steel pipes provide strength and stability in a range of building applications. Pipes are hollow, cylindrical tubes that are available in a wide range of sizes.

Engineers frequently use steel pipes to suit the needs of water, oil, and gas projects. Costs £35-£115 per metre.


  • Strong
  • Available in different sizes
  • Good for additional tradespeople


  • More expensive to use due to its material

T-Beam Cost

A load-bearing tee beam, also known as a T beam, has a T-shaped cross-section. The flange is at the top of this cross-section, with the vertical web below it. Tee beams can sustain huge loads, but they lack the bottom flange of an "I" beam, making them less suitable for applications.

A T-beam costs £10-30 per metre

T-beam RSJ


  • This is the most popular RSJ beam
  • Affordable steel beam


  • It lacks a bottom flange

Custom Shapes

Engineers today aren't restricted to using simply the most prevalent shapes. Custom metal fabrication enables the creation of a wide range of unique structural steel shapes for any project.

Metal fabricators can mould steel into various shapes for individual applications using cutting-edge tools and processes such as water jets, laser, and plasma cutting.

If you can imagine it, chances are a skilled metal fabricator can make it happen. The price depends on the shape and size and the type of RSJ beam you are looking for.


  • It fits the building perfect to its size


  • It can be more expensive
  • More time-consuming

Benefits of RSJ Installation

The benefits of RSJ (rolled steel joist) beams are ongoing. These beams have been employed for several applications for years due to their immense strength, support, and quality.

They're commonly utilised in industrial and commercial construction, and they're becoming more popular in-home projects like new floors, patios, and decks. Because the material is easily twisted and handled, it is a very versatile option.


Steel is well-known for its environmental friendliness. Steel is employed in so many projects because the building sector has improved its green credentials in recent years.

The number of times RSJ beams may be recycled is unlimited, which means less waste is transported to the landfill.

Steel is also regarded as a very green alternative because it does not emit greenhouse emissions. In comparison to alternatives like concrete and wood, RSJ steel beams are also extremely cost-effective.


Steel has the highest strength-to-weight ratio of all the building materials and can withstand a tremendous amount of stress and weight. It can endure almost whatever the weather can throw at it, which is why it is frequently used in areas where the weather can be particularly harsh.

Cut, form, shape, and bend RSJ beams into a variety of dimensions and lengths. They're also fire-resistant and don't require any chemical treatment. Steel that has been galvanised will not rust. It can even keep structures from collapsing during hurricanes and earthquakes.

RSJ benefits


Steel beams, as previously indicated, are custom-made to your specifications. Because of the material's flexibility, the design is conceivable. Steel may be shaped and sized to any size and shape.

The incredible part is that the moulding does not affect the material's quality. Furthermore, because of its flexibility, it is safer to use because it can be easily recycled.

Gives a Sleek Finish

While the look of unfinished or knotty wood may be desired in some rustic designs, steel provides a streamlined alternative. Steel, unlike other options such as wood, is made, so it will be smooth and free of the knots and imperfections that characterise wood.

How Much Does It Cost to Remove an RSJ?

If you're re-building a supporting wall or knocking down the wall above the steel beam, you may want to remove an RSJ. Another reason to remove an RSJ is to replace it with a different type of support beam or to replace it with another RSJ.

Removing an RSJ is a difficult task that should be carried out carefully and properly. If you are unsure about the job requirements while removing an RSJ, you should consult a structural engineer for advice on the optimum approach for removing your rolling steel joist.

If you're removing a rolled steel joist, you'll need to think about whether you need to replace it with something else.

RSJ removal

If there is still a load-bearing fixture above where the RSJ was, you'll need to replace it with something else, such as a wall or another support beam. For the labour of uninstalling your RSJ, a builder would charge you between £20 and £35 per hour.

Various additional fees may be incurred while deleting an RSJ. You may need to consider waste removal. A one-week skip rental would set you back between £200 and £250 as you will need this due to it being a messy job. Then you need to re-plaster and re-decorate, which is spoken about above.


Q: What does RSJ stand for?

A: RSJ stands for rolled steel joist.

Q: How much wall does an RSJ need to sit on?

A: To build a rolled steel joist at either end of a solid masonry wall in good condition, you'll need at least 150mm of cast concrete for it to sit securely on the wall.

Q: How long does an RSJ last?

A: The protective coating used in the steel storage yard is intended to safeguard the steel used in construction and is expected to last at least 100 years, so it is defiantly worth having one.

Q: Do you need planning permission to install an RSJ?

A: No, because it is an internal change to a domestic property, you usually don't, but we recommend checking with your local planning authority.

If your home is a listed building, any work you do will require listed building consent. For more information, go to the planning section of your municipality's website. If you are working on a building, then planning permission will be required for safety reasons.

Q: What is RSJ used for?

A: To ensure structural integrity, RSJs are rolled from a single piece of structural steel (S275JR grade) and used to support walls and floors when making an opening in a load-bearing wall or when building an extension.

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Author: Emma M

I am a Liverpool-based freelance writer with a degree in Media and Communications. I specialise in product reviews, home improvement and DIY content. I am also experienced in social media management and content marketing.