Material and cross-section, shared by every verification. Change the verification above and these stay as they are.
Checks the bearing of a solid-timber or glulam member on a support: compression perpendicular to the grain at the ultimate limit state, to SIA 265:2021. Every step shows its formula and the clause it comes from.
You enter the wood type, strength class, load duration, service class and the width b of the member; the type of support; the contact area (bearing length lA and width bA, or the area directly); the design support reaction Rd; and the design compressive strength perpendicular to the grain fc,90,d from your copy of SIA 265.
You get the contact area, the design stress, the design resistance and the utilisation with a pass or fail, each with its clause. With the Basic plan, the same calculation prints as an A4 calculation note.
A glulam beam GL24h, 280 mm wide, in service class 1, bearing over 280 × 280 mm on a general support, with a design reaction of 37 kN. These are the module's own results for its worked example, computed when this page was built.
| Input | Value | Ref. |
|---|---|---|
| Wood type | Glulam | |
| Strength class | GL24h | |
| Load duration ηt | Short to permanent | § 2.2.6 |
| Service class ηw | 1 | § 3.2.1.3 t.4 |
| Section width b | 280 mm | |
| Type of support | General | § 3.3.2.1 t.8 / 3.4.2.2 t.9 |
| Contact area given by | Bearing length and width | |
| Bearing length lA | 280 mm | |
| Bearing width bA | 280 mm | |
| Design support reaction Rd | 37 kN | |
| Design compressive strength ⟂ grain fc,90,d | 1.9 N/mm² | § 3.3.2.1 t.8 / 3.4.2.2 t.9 |
| Load inclined to the grain? | No — perpendicular | § 4.2.2.3 |
| Step | Value | Ref. |
|---|---|---|
| Contact areaA = lA · bA | A = 78,400 mm² | |
| Load duration factor | ηt = 1.00 | § 2.2.6 |
| Moisture factor | ηw = 1.00 | § 3.2.1.3 t.4 |
| Design stressσc,90,d = Rd / A | σc,90,d = 0.472 N/mm² | |
| Design resistance ⟂ grainfRd = fc,90,d · ηt · ηw | fRd = 1.900 N/mm² | § 4.2.2.2 (11) |
| Compression perpendicular to the grainσc,90,d ≤ fc,90,d | η = 0.248 · Pass25 % of the capacity used | § 4.2.2.2 (11) |
| Alternative methodSIA 265 §4.2.2.2 allows the verification perpendicular to the grain to be carried out instead according to annex C. That method is not implemented here. | SIA 265 annex C | § 4.2.2.2 |
Verified clause by clause against SIA 265:2021 and against independent calculations used on real projects, before release.
The value SIA 265 gives for the type of support you choose. The higher value for front wood and end supports is admissible only if the larger deformations do not impair the behaviour of the member.
Not here. The fire situation is a separate module that reduces the contact surface for charring.
The full calculation is shown on screen, free and without an account. A print-ready A4 calculation note is part of the Basic plan.
Norm: SIA 265:2021 · Page updated: 20 October 2026