My Beam Sticks Out Beyond the Eaves — What Are My Options?

In some loft conversions — particularly where a ridge beam or floor beam runs close to the eaves — the beam end may project beyond the rafter foot or the wall face. This protrusion cannot simply be ignored: it risks intercepting the roofline, the fascia board, or the soffit line — and in some cases it can prevent the roof from being properly closed at the eaves.

There are three accepted options for dealing with a beam that is too long at its end.

Option 1: Chamfer the Beam End

The beam can be cut at an angle at its end, reducing its depth at the support location. This is the simplest and cheapest solution.

Constraint: The reduction in section at the support must not be more than 30% of the beam’s overall depth at the bearing point. Beyond this, the reduced section cannot carry the shear force at the support, and the chamfer would compromise structural performance.

If a 30% chamfer is sufficient to achieve clearance at the eaves, this is the preferred solution.

Option 2: Crank the Beam

The beam can be fabricated with a crank — a change in direction at a point near the support — allowing the end of the beam to step down (or up) to clear the eaves construction.

Constraints:
– The crank must be made as a full-strength butt weld in the workshop (not on site) — see How Should Cranked Beam Joints Be Made? for details
– If the crank point is more than 200 mm from the support, the structural calculations may need to be updated to account for the revised load path at the crank. Raise a Change Request before fabrication.
– Cranked beams are more complex and expensive to fabricate than straight beams

Option 3: Trim the Beam

The beam end can be cut shorter so it no longer projects beyond the eaves. However, this changes the bearing length at the support and potentially changes the effective span.

Constraints: This option always requires a check by the structural engineer before cutting. The bearing length affects both the beam capacity and the load transferred to the padstone or wall below. Provide PorthouseDean with the proposed trimmed length via a Change Request.

Planning Ahead

All three options are easier to deal with at the design stage than after the beam has been fabricated and delivered to site. When you receive the structural drawings, check whether the beam end clearance works with the architectural details. If it does not, raise the issue as a Change Request before instructing your fabricator.

Contact us or raise a Change Request — changes are most straightforward before fabrication begins.