RSJ Installation

RSJ Installation (London, UK) — Clear Breakdown

RSJ (Rolled Steel Joist) installation is typically required when removing a load-bearing wall, forming open-plan spaces, or supporting loft conversions and extensions.

🔧 What’s Included

1. Structural engineer calculations (if not already done)

2. Temporary propping (Acrow props + strongboys)

3. Supply of RSJ (fabricated to spec)

4. Padstones (precast or engineering brick)

5. Cutting pockets & bearing prep

6. Lifting & installing the beam

7. Bolt connections / splice plates (if required)

8. Building Control inspection

9. Fire protection (plasterboard encasement)

💷 Typical Costs — London 2025

Labour (installation only)

• £450 – £650 per RSJ

  • Standard internal beam

  • Ground or first floor

  • 2–3 operatives

Supply (steel only)

• £120 – £250 per metre

  • Example: 203 UB / 152 UB (S275)

  • Price depends on size & weight

Padstones

• £40 – £80 each
  (usually 2 required)

Fire protection

• £150 – £300

  • 2 × layers fire-rated plasterboard + skim

Structural engineer

• £250 – £450

  • Calculations + drawings (one beam)

📊 Common All-In Examples

(Prices excl. VAT unless stated)

🧱 Typical RSJ Sizes (examples only)

• 152 × 89 UB — small openings

• 203 × 102 UB — standard house openings

• 254 × 146 UB — wide spans / heavy loads
  ➡️ Final size must be confirmed by a structural engineer.

⚠️ Important Notes

• Building Control must approve

• Fire rating usually 30 or 60 minutes

• Party Wall notice may be required

• Incorrect sizing = structural failure risk

If you want, I can:

• 🔹 Calculate exact RSJ size & cost from your opening/span

• 🔹 Prepare an Excel cost breakdown

• 🔹 Add RSJ logic into your LASTING LTD calculator

• 🔹 Provide client-ready wording for quotes/contracts

Just tell me the opening width, wall type, and number of floors above.