Gambrel trusses with four top-chord segments per truss breaking at the pitch change, purlins per roof face, four skin faces plus a bent break cap where the pitches change. The spec pitch is the UPPER slope (factory shallow-gambrel band 4-6/12) and the steeper LOWER slope derives at twice that, clamped into the 8-12/12 truss band.
Also called: barn roof · two pitch roof · hay barn · dutch barn
- 1The break sits at a quarter of the span from each eave.
- 2Chords are plumb-cut at the eave, break and ridge so they butt instead of occupying the same wood.
- 3The end wall silhouette is a pentagon (eave corners, break knees, apex) used by both the steel gable line and the insulation fill.
- 4Rake boards follow both slopes: level return at the eave, knee at the break, plumb butt at the apex.
- 5Span rails: minimum 20ft, typical factory band to 48ft, hard ceiling at 60ft — between them the truss is flagged as special order rather than refused.
- 6A snow-drift note fires at the pitch break because the surcharge there can exceed the uniform design load.
A gambrel is defined by the relationship between its two slopes, so letting someone author both independently lets them draw a shape that is not a gambrel and then try to order it. The lower slope is derived from the upper one, against published truss-factory ranges. Spans past the stock ceiling are marked special order rather than blocked, because a 55ft gambrel is a real order — just not one that comes off a shelf.
- Gambrels drawn with arbitrary slope pairs that no truss plant builds.
- Quoting a gambrel span that turns out to be a custom engineering project.
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Twenty minutes, your numbers, no slide deck. We’ll build one of your real buildings in front of you and send you the estimate link at the end — yours to keep either way.
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