Thinking of having a shed added to your property? In this guide, we’ll look at the average costs involved in having different types of sheds installed.
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First things first; what is an RJS? Well, RSJs, a.k.a. rolled steel joists, are tall I- or H-shaped construction beams that comprise either cold-rolled steel or hot-rolled steel. Both options are initially rolled at high temperatures, but cold-rolled steel undergoes additional processing with cold reduction materials after being hot-rolled. This can result in cold-rolled steel being stronger than its hot-rolled counterpart.
Whatever the case, RSJs are utilised to ensure the structural integrity of a building withstands during construction work, such as when two rooms are being converted into one with a wall being knocked down between them. RSJs can support floors and walls during said work.
When hiring a service to substantially alter your property (e.g. to have an extension added to your kitchen as a means of extending it), it’s important to consider potential added costs such as that of an RSJ installation.
In this guide, we’ll discuss the average cost of having an RSJ installed based on the size of the property and the type of project in question. We’ll also explore other relevant subtopics such as potential cost factors and how to choose the right person/company for the job. Let’s begin!
Factors Influencing RSJ Installation Cost
Before looking at the average cost estimates for RSJ installations, it’s important to be aware of the numerous factors that can influence the cost.
Size and Type of RSJ
Naturally, the larger the RSJ beam, the more expensive it will likely be. RSJ sizes generally range from 1 metre to 10 metres for residential projects but can often be longer in the case of commercial projects. RSJs can also have varied weights and strengths depending on the project in question.
In terms of the type of RSJ, universal beams and universal columns tend to be the costliest options. Double beams can be slightly cheaper, while T-beams and lintels are among the most affordable options.
Of course, the size and type needed for any given project will vary and the cheaper examples may not be suitable depending on the project. Always ensure that an appropriate professional or professionals determine the right type of RSJ for your project. This is not a DIY task unfortunately nor is an installation in the vast majority of cases. See our ‘DIY Vs. Professional Installation’ section further down for additional details.
Site Accessibility
How accessible the work area is can also play a role in the total cost. After all, if it is difficult to access the site, more time will likely be needed to fully install the RSJ in a correct and safe manner.
As a result, the price of labour for the RSJ instalment will generally be higher in these scenarios, leading to a larger bill overall. This can apply whether it be a residential property or commercial building.
Labour Costs
You must hire a structural engineer to determine the size and type of RSJ needed and you’ll likely want to hire them to install the RSJ too. That said, a builder could perform the installation once a structural engineer has determined the exact requirements for the RSJ instalment.
Structural engineers tend to charge somewhere in the region of £50 to £100 per hour. Costs tend to be toward the low end of this range in places like northern England, Scotland and Northern Ireland (and, in many areas in these regions, labour prices can end up below £50 per hour).
On the other hand, structural engineer labour costs are closer to £100 in the southeast of England with London being one of the costliest parts of the UK in terms of tradesperson fees.
Additional Structural Support Requirements
Where extra supports are needed, RSJ prices generally end up higher than they would otherwise be. For instance, temporary supports may be needed during the RSJ installation, likely adding to the final bill.
Finish and Treatment of RSJ
Other costs that may apply can include painting or galvanising the RSJ. A suitable steel paint or zinc coating may be used to achieve this. This may cost somewhere in the region of £50 to £200, although this will partly depend on whether you need to hire a separate professional painter or if the RSJ installer can do this themselves.
Average Cost Estimates
Note: The cost of an RSJ can vary depending on its weight and overall dimensions, so take the cost estimates below that are based on length with a grain of salt.
The average cost of an RSJ installation in the UK will vary significantly depending on the project in question as this will, in turn, affect key cost factors such as the price of labour and, of course, the size and type of RSJ needed. So, how much does an RSJ cost?
Let’s start with average costs for residential projects. Please note that all costs given below factor in the price of labour and the cost of the RSJ itself (i.e. supply cost). With the use of a common type of RSJ such as a universal beam or universal column, a one metre installation (such as for a single external doorway) may cost somewhere in the region of £500 to £1,500.
In the case of a two-metre-long RSJ, this will probably cost around £1,000 to £2,000 and may be used for an external window opening project, a double doorway or in the case of knocking down a single wall. That said, you may need a three metre RSJ for knocking down a single wall or even for having bifold doors added. This length of RSJ will likely set you back between £1,200 and £2,800.
To have a four metre RSJ fitted, expect a total bill of approximately £1,300 to £3,000. This may be installed as part of a house extension. Lastly, should your residential project require a five to ten metre RSJ installed, which may be used for some house extensions or even loft conversions, you’d be look at paying about £1,500 to £6,000.
Moving on to commercial projects, again, a 5 to 10 metre RSJ (which may be used for some commercial projects) is likely to cost around £1,500 to £6,000. For a 10 to 20 metre RSJ, you may end up paying between £3,000 to £9,500. For an even longer RSJ, prices may exceed £10,000 in some cases.
| Length of RSJ | Labour Cost | Supply Only Costs | Total Cost |
|---|---|---|---|
| 1 metre | £350 to £800 | £150 to £700 | £500 to £1,500 |
| 2 metres | £600 to £1,200 | £400 to £800 | £1,000 to £2,000 |
| 3 metres | £750 to £1,800 | £450 to £1,000 | £1,200 to £2,800 |
| 4 metres | £800 to £1,800 | £500 to £1,200 | £1,300 to £3,000 |
| 5 to 10 metres | £900 to £3,500 | £600 to £2,500 | £1,500 to £6,000 |
| 10 to 20 metres | £1,800 to £5,000 | £1,200 to £4,500 | £3,000 to £9,000 |
Potential Additional Costs
Along with how much installing a steel beam costs, it’s important to consider any added expenses that may apply. Here are some notable examples.
Building Regulation Fees
Construction work such as the installation of an RSJ requires that a suitable professional performs the instalment and does so in adherence with building regulations.
In many cases, this will entail additional fees with the total often depending on the type and cost of the work required. For an RSJ installation, building regulation costs may come to around £160 to £325.
If in doubt, you can always consult with your structural engineer or/and local builder (if they are to perform the RSJ installation) regarding the expected building regulation fees. In fact, discussing potential added costs in general before the work gets underway can help limit or avoid unexpected surprises in terms of your final bill.
Planning Permission Costs
Planning permission probably won’t be needed for simply having an RSJ installed. That said, the primary work taking place that requires an RSJ installation may indeed require planning approval (e.g. many house extensions need planning permission approval).
It’s important to look into this well in advance. Along with planning permission costs (assuming planning approval is required, of course) being around £145 to 260, it generally takes up to eight weeks for a planning permission application to gain approval.
Costs for Removing an Existing Wall
If having an existing wall removed and needing an RSJ installed as part of this project, you’ll want to know how much the wall removal itself may cost.
On average, the price of having a load bearing wall removed is likely to fall somewhere in the region of £1,000 to £3,000 depending on the size of the wall. Of course, this is a common scenario where an RSJ must be installed (and done so by a suitable professional with a structural engineer performing the necessary measurements at the very least).
Waste Removal Costs
Whether you’re having an existing wall removed, a double doorway added, or want professionals to build an extension on your property, you’ll need to consider the cost of waste removal too.
This assumes that the professional(s) performing the relevant work do not offer to remove any project waste for no extra cost as part of their initial quote, although this often won’t apply, unfortunately.
To rent a skip for a week will likely cost around £100 to £300. The total price will largely depend on the size of skip needed, which, in turn, will be determined by the type and scale of construction projects taking place that necessitate waste removal.
Time Frame for Installation
The average duration for an RSJ installation is one to two days for a 1 to 2 metre RSJ. In the case of a 3 to 4 metre RSJ, expect it to take two to three days. As for a 5 to 6 metre RSJ, it should take about two to four days, with the estimated time frame reaching three to four days for a 7 to 8 metre RSJ and also about three to four days in the case of a 9 to 10 metre RSJ. Lastly, for a relatively large, commercial project, having professionals fit a 10 to 20 metre RSJ may take around four to seven days.
In summary, here are the average time frames for different RSJ instalments:
| Size of RSJ | Duration to Install |
|---|---|
| 1 metre | 1 to 2 days |
| 2 metres | 1 to 2 days |
| 3 metres | 2 to 3 days |
| 4 metres | 2 to 3 days |
| 5 to 10 metres | 3 to 4 days |
| 10 to 20 metres | 4 to 7 days |
DIY Vs Professional Installation
Note: If you own a commercial property as opposed to a residential property, do not install an RSJ by yourself. Depending on local regulations, it may prove technically legal in some cases, but the complexity involved simply makes it too ill-advisable to justify a DIY installation. Even with a correct DIY instalment, you could certainly open yourself up to legal troubles whether in the short-term or down the line. There’s simply too much risk and too much to consider for such a DIY project.
While it is legal and possible to install an RSJ DIY, you should only do so once all initial requirements are met (i.e. a structural engineer must determine what size and type of RSJ is needed and you’ll need approval and possibly instructions from building control) and if you know exactly what’s involved.
If you are in any doubt whatsoever, hire a professional, as this is a complex project and accuracy is essential for the safety of you and everyone else in your property.
If you are absolutely sure that you have the right skills and knowledge needed and particularly if it is a relatively small RSJ, you can go ahead and perform the installation once all initial requirements are met. Again, though, we are talking about a residential property RSJ installation. If you own a commercial property and need an RSJ added, hire a professional to do so.
Proceed with caution and take your time to ensure that the RSJ is installed correctly and safely. Also, be sure that you have all the necessary information, advice and details from the structural engineer and building control before proceeding. You must know exactly what you need for a correct and safe instalment, including any and all materials required and the details of each exact step that must be followed and the order in which they must be followed.
Make sure you have answers to any questions you might have before getting to work. Simple miscalculations or errors can lead to safety issues and even still, legal issues can still arise, such as in the case of a negligent DIY installation. As you can see, it is not exactly recommended that you install an RSJ DIY, but if you are sure, you are suitable to perform this work, make sure to consider everything listed above and any other steps that may apply in your case.
If you were to add an RSJ DIY, you might end up saving around £400 to £2,000 in an average scenario. To be more specific, adding a 1 to 2 metre RSJ DIY could save you around £400 to £1,200 with savings reaching about £800 to £1,800 for a 3 to 4 metre RSJ or anywhere from approximately £900 to as much as £3,500 or more in the case of a 5 to 10 metre RSJ installation.
Choosing a Contractor
You’ll need to hire at least one contractor (if not several) for an RSJ installation. Firstly, as discussed earlier, you must hire a structural engineer to determine what size and type of RSJ is needed.
Next, you’ll either want to stick with the structural engineer or hire a local and experienced builder who can install an RSJ. You’ll also need to get approval from building control or have the structural engineer or local builder do so.
When it comes to hiring a structural engineer, along with them having sufficient skills and knowledge in their field of work and be qualified to perform the work in question too.
In most cases, a structural engineer will have at least a bachelor’s degree in structural engineering or a similar field (e.g. construction or mathematics). Many structural engineers will have structural engineer master’s degrees or a master’s degree in a related area. Whatever the case, you’ll want to ensure that a structural engineer is qualified for the job.
A way of verifying their qualifications is to check that they are a member of the Institution of Structural Engineers (either as a chartered, technician or associate-member) or/and they are registered either CEng, IEng or EngTech with the UK’s Engineering Council. More details on verifying a structural engineer’s qualifications/certifications can be found through the official website of the Institution of Structural Engineers.
Beyond that, whether you are only looking for a structural engineer or you opt for hire a structural engineer to determine what sort of RSJ is needed before hiring a local builder to install the RSJ, in any case, you’ll want to secure several quotes for each type of contractor you wish to install.
By landing 3+ quotes in each case, you can then compare several options before deciding which contractor/company is right for the job(s) in question. You’ll want to consider not only their pricing but their qualifications (if applicable), levels of experience and any online reviews or ratings they have.
Making an informed decision may help you get better value for money. All in all, though, qualifications (in the case of a structural engineer) and experience are most important when looking to hire professional(s) for important work such as that related to adding an RSJ.
Conclusion
Having an RSJ installed in a safe and accurate matter is essential for many construction-related projects, whether it be in a residential or commercial property.
Along with ensuring that you hire the right individual(s) for the work required and those qualified to do so, it’s important to consider all the potential costs involved and any other requirements (e.g. building control approval or planning permission approval for the larger project that requires an RSJ installation).
As discussed earlier, the cost of RSJ installations can differ depending on a range of factors, so having a detailed quote from the get-go that considers as many potential costs as possible should give you a reasonably clear idea as to what you’ll need to budget for. That said, always have a larger budget than you initially assume is needed as further additional costs can always prop up.
With the right contractor(s) involved and sufficient time spent on the project, you can have an RSJ installed professionally to ensure your home is safe and sound when undergoing substantial alterations such as having a load bearing wall demolished to turn two rooms into one or to have an extension added at the rear of your property.
Sources
https://buildingcontrol.bathnes.gov.uk/building-control-services/building-control-fees-and-charges
https://www.gov.uk/planning-permission-england-wales/after-you-apply