Steel Beam Installation Guide: RSJ Costs and Specifications Ireland
Removing a load-bearing wall to create an open-plan living space is one of the most popular home improvements in Ireland. This guide explains everything you need to know about steel beam (RSJ) installation.
What is an RSJ?
RSJ stands for Rolled Steel Joist, though the term is often used interchangeably with steel beam, I-beam, or Universal Beam (UB). These structural steel members carry loads from the floors and roof above when load-bearing walls are removed.
Steel Beam Costs in Ireland 2025
Supply Costs (Steel Only)
- 152x89 UB (small spans): €20-30 per metre
- 203x133 UB (medium spans): €35-50 per metre
- 254x146 UB (larger spans): €55-80 per metre
- 305x165 UB (large spans): €80-120 per metre
Installation Costs (Complete Job)
A typical wall removal with steel beam installation costs:
- Small opening (up to 2.5m): €1,500 - €3,000
- Medium opening (2.5m - 4m): €2,500 - €5,000
- Large opening (4m - 6m): €4,000 - €8,000
These costs typically include:
- Structural engineering design
- Steel beam supply
- Temporary support (Acrow props)
- Installation by qualified builders
- Making good plastering
How Steel Beam Sizes Are Determined
A structural engineer calculates the required beam size based on:
1. Span Length
The distance the beam must span between supports. Longer spans require larger beams.
2. Loading
- Dead loads (permanent): Floor weight, walls above, roof structure
- Imposed loads (variable): Furniture, people, storage
3. Support Conditions
The padstones or steel columns that support each end of the beam must transfer loads safely to the foundations.
4. Deflection Limits
Beams must not deflect (bend) excessively under load, typically limited to span/360.
The Installation Process
1. Structural Design
A chartered structural engineer designs the beam, connections, and supports based on a site survey and structural calculations.
2. Building Control
For most wall removals, you’ll need a Commencement Notice submitted to the local Building Control Authority.
3. Temporary Support
Before any wall is removed, temporary Acrow props support the floors and roof above.
4. Wall Removal
The load-bearing wall is carefully removed in sections.
5. Beam Installation
The steel beam is lifted into position, supported on padstones or steel posts at each end.
6. Making Good
Plasterwork, decoration, and finishing complete the installation.
Common Questions
Do I Always Need a Structural Engineer?
Yes. Building Regulations require structural design by a competent person for any works affecting structural elements. A chartered structural engineer provides the required calculations and certification.
Can I Use Timber Instead of Steel?
For small spans, engineered timber (LVL or glulam) may be suitable. However, steel typically offers smaller section sizes for equivalent load capacity, making it preferred where headroom is limited.
How Long Does Installation Take?
A typical wall removal takes 2-5 days depending on complexity, including temporary support installation, wall removal, beam fitting, and initial making good.
What About Fire Protection?
Steel beams may require fire protection (intumescent paint or boarding) depending on their location and the building’s fire strategy.
Tips for Homeowners
- Get structural engineering done first - Before approaching builders, have your beam designed and specified
- Check builder credentials - Ensure your builder has experience with structural steelwork
- Don’t remove walls without design - Removing load-bearing walls without proper support can cause serious structural damage
- Consider services - Walls often contain pipes, wires, and ducts that need rerouting
- Plan for disruption - Factor in time for dust and noise during the works
Conclusion
Steel beam installation is a well-established construction technique that can transform your home’s layout. With proper structural engineering design and competent installation, it’s a safe and effective way to create open-plan living spaces.
Contact Brickbolt Engineering for expert structural design for your wall removal project.
