Load Tables
203×133×25 RSJ Beam: Load Capacity, Span Tables, and Prices 2026
Complete guide to the 203×133×25 RSJ beam. Find safe spans, load capacity, 2026 prices, and whether this size is right for your wall removal or extension.
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Your Complete Guide to RSJ Steel Beams
Professional calculators, comprehensive load tables, installation guides, and expert advice for Rolled Steel Joists and structural steel beams. Everything you need for safe, compliant construction.
30+ Expert Guides
5 Free Calculators
2026 Pricing Data
Span 4.5m
Load 45 kN
Status Verified
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Everything you need for RSJ beam selection and installation
Calculators
Beam size, load capacity, cost, and deflection calculators for precise calculations
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Complete size charts, span tables, and safe load references for all beam sizes
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Step-by-step installation, knockthrough, and project guides with expert tips
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RSJ vs alternatives, materials, finishes, and cost analysis for informed decisions
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What Is an RSJ Beam? A Complete Beginner's Guide
New to structural steel? Our plain-English guide explains what RSJ stands for, how rolled steel joists work, common sizes, typical costs, and whether you need a structural engineer for your project.
- What RSJ, UB and I-beam really mean
- Typical sizes and 2026 prices
- Engineer and Building Control requirements
Latest Articles
Expert insights and practical guides
Load Tables
RSJ Beam Sizes Explained: How to Choose the Right Steel Beam for Your Project 2026
Understand RSJ beam sizes in plain English. Learn what the numbers mean, which size is right for your span, and see a quick-reference size chart for UK homes.
Building Regulations
What Is an RSJ Beam? Complete Beginner's Guide to Rolled Steel Joists 2026
Learn what an RSJ beam is, how it's used in UK construction, common sizes, costs, and whether you need a structural engineer. Plain-English guide for homeowners and builders.
DIY Projects
What Size RSJ for Loft Conversion? Steel Beam Span Tables and Costs UK 2026
Find the right steel beam size for your loft conversion. Includes ridge beam and floor beam span tables, 2026 prices, and Building Control requirements.
Calculators
RSJ Beam Weight Calculator: How Heavy Is Your Steel Beam? 2026
Calculate the total weight of any RSJ or UB beam with our free 2026 guide. Includes weight-per-metre tables, handling limits, and delivery advice.
Building Regulations
Do You Need a Structural Engineer for an RSJ? UK Requirements Explained 2026
Find out when you legally need a structural engineer for an RSJ beam, what they do, how much they cost, and what happens if you skip this step.
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All structural work should be designed by a qualified structural engineer and approved by Building Control. Our guides provide information only and don't replace professional advice.