When structural timber is specified, it is common to see call-ups such as F17, E14, LVL 13, LVL 15 or LVL 16. But these numbers are often misunderstood. The key point is simple: “E” refers to stiffness, not strength.
Stiffness affects how much a member deflects under load. Strength is what allows the member to carry the load. Both matter, but they are not the same thing.
Wesbeam e-beam LVL has an average short-term modulus of elasticity of 13,200 MPa, commonly referred to as E13.2.
F17 is often nicknamed “E14” because its average short-term modulus of elasticity is 14,000 MPa.
While that looks different on paper, the practical difference in deflection is very small in most common residential applications, especially when the right e-beam size is selected.
Switching from a common F17/E14 call-up to Wesbeam e-beam E13.2 LVL is not a downgrade.
E-rating relates to stiffness. Strength is a separate requirement, and Wesbeam e-beam’s minimum bending strength is equal to or higher than F17, depending on member depth.
That means e-beam provides a strong, reliable and engineered alternative for common joists, lintels, beams and rafters used on edge.
A higher E-rating is not always the smartest or most economical answer. In timber design, geometry has a major impact on performance. Increasing member depth can often improve stiffness more effectively than simply choosing a higher-rated product. That is why Wesbeam’s size-swap approach matters. It allows builders, designers and estimators to move from common F17 call-ups to practical e-beam sizes that match or exceed performance.
For common on-edge applications:
Previous F17 call-up | Switch to Wesbeam e-beam | Increase in Stiffness |
|---|---|---|
120 x 45 F17 | 130 x 45 e-beam | +20% |
140 x 45 F17 | 150 x 45 e-beam | +16% |
190 x 45 F17 | 200 x 45 e-beam | +10% |
290 x 45 F17 | 300 x 45 e-beam | +4% |
For anything outside these common swaps, check Wesbeam Span Tables or speak with the Wesbeam Engineering Team.
Wesbeam e-beam LVL gives builders, engineers, merchants and frame and truss manufacturers a reliable, locally supported option. It offers:
Engineer-grade consistency
Australian-made supply
Clear span table and software support
e2s, H2 LOSP and H3 LOSP treatment options
Practical size swaps for common applications
Local technical and engineering support
The best way to avoid confusion is to specify the right product from the start.
If drawings call up F17, E14 or another LVL grade, do not rely on the number alone. Consider stiffness, strength, size, application and availability.
For substitutions, unusual applications or specification support, speak with Wesbeam before making the change.
