The CivilWeb Flitch Beam Design Spreadsheet is designed to improve the speed and accuracy of the design process for flitch beams. Fully compliant to BS EN 1995-1-1 or BS268-2, the spreadsheet completes the full calculations required by the standards and presents clear and concise results with professional standard outputs.
The CivilWeb Flitch Beam Design Spreadsheet can be purchased lower down this page for only £19.99. Or why not buy our best value bundle? Our Full Timber Design Spreadsheet Suite can be purchased at the bottom of this page for only £49.99. This suite includes all 11 of our timber design spreadsheets and represents an incredible saving of more than 75%.
Flitch beam design offers a smart solution when timber alone isn’t strong enough, but steel on its own isn’t practical. By combining the natural beauty of wood with the strength of steel, flitch beams provide a versatile and efficient structural option for residential and commercial construction.
What is a Flitch Beam?
A flitch beam is a composite structural beam made from:
- Two (or more) timber members
- A steel plate (“flitch plate”) sandwiched between them
- Bolts or screws connecting the assembly together
This design merges the best of both materials:
- ✅ Timber provides economy, insulation, and ease of connection
- ✅ Steel adds extra bending strength and stiffness
- ✅ The result is a compact, high-capacity beam
Flitch beams are commonly used in:
- House extensions and loft conversions
- Long-span floor beams and lintels
- Renovations where increased strength is required without large beam depths
Methods for Flitch Beam Design
✔️ Manual Calculations
- Based on beam theory and composite section properties.
- Effective but time-consuming, especially when checking bolt design.
✔️ Manufacturer’s Span Tables
- Rarely available, as flitch beams are often custom-built.
✔️ Spreadsheets & Software
- Automate bending, shear, and deflection checks.
- Quickly assess multiple timber-steel combinations.
- Provide fast, accurate pass/fail results for different spans and loads.
Why Use a Flitch Beam Design Spreadsheet?
A Flitch Beam Design Spreadsheet simplifies the process by:
- Calculating bending capacity, shear strength, and deflections
- Checking bolt spacing for shear transfer
- Allowing quick adjustments for span, loads, and timber/steel sizes
- Reducing manual calculation errors
- Producing professional outputs for reports and site checks
How to use the Flitch Beam Design Spreadsheet
- Input Applied Loads
- Perpendicular compression
- Bending moments due to eccentric loading or lateral forces.
- Shear forces from horizontal loading.
- Material Properties
- Timber strength and steel strength.
- Beam Dimensions
- The user can then input flitch beams with any number of timber and steel units with either steel or timber units on the outside of the beam. The user can input any depth and breadth of timber and steel sections for analysis.
- Connection Details
- Finally the user can input bolts size and strength. The spreadsheet will determine the minimum spacings required.
The CivilWeb Flitch Beam Design Spreadsheet automatically completes all the calculations required for design to the design standards BS EN 1995-1-1 or BS268-2. The results are presented in a clear and professional manner with full calculation readouts and simple green/red results shown in a simple optimisation score.
The spreadsheet also automatically completes the design calculations for other similar flitch beam sections and presents these in a graph which the designer can use to optimize the flitch beam design at a glance, saving hours or iterative calculations.
Who Is It For?
This spreadsheet is ideal for:
- Structural Engineers designing hybrid timber–steel beams
- Architects checking feasibility of flitch beams in projects
- Builders & Contractors ensuring beam safety on site
- Students learning composite beam design principles
Why Use This Spreadsheet?
- Save hours compared to hand calculations
- Avoid expensive errors in hybrid beam design
- Get instant, code-compliant results
- Perfect for both preliminary sizing and final checks
Flitch beam design provides a clever balance between timber and steel, offering strength, economy, and practicality in a single hybrid member.
While manual calculations can be carried out, a design spreadsheet saves time, improves accuracy, and allows rapid iteration for different design options.
