Every post-frame roof shape

Six roof shapes from the NFBA glossary, each with its own framing configuration, material package and engineering limits — and each modelled, not faked.

What it is

A catalogue of roof SHAPES (gable, gambrel, hipped, mansard, monitor, monoslope), distinct from the roofing SYSTEM (the panel product on the shape). Each entry carries a display name, trade aliases, the NFBA definition, the framing configuration that builds it, the material package the takeoff must count, and a flag for whether its geometry has shipped.

Also called: roof types · roof styles · NFBA roof shapes · gable gambrel hip mansard monitor monoslope

See it, piece by piece
01

Six roof shapes, each modelled rather than relabelled

Gable, single slope, gambrel, hip, mansard and monitor, taken from the NFBA glossary with the trade names builders use for them. Each one branches the whole build: wall heights, trusses, purlins, skins, trim, the checks and the takeoff. A shape whose geometry has not landed says so out loud rather than drawing a gable behind a different name.

Design — Roof
RoofHide
Roof type
Gable

Also known as: Saddleback roof. Two roof planes whose upper edges meet at a ridge — the most common shape in cold and temperate climates. Framing: Common trusses at the spec’d spacing with gable trusses at each end (2×6 chords, king-post web), 2×4 purlins laid flat, rake and eave overhang framing.

Gable
Gambrel
Hipped
Mansard
Monitor
Monoslope
Roofing system
Ribbed steel (exposed fastener) — min 3/12

Search systems + products — six standard systems, plus every scanned manufacturer panel.

Roof pitch(/12)
−4+
Eave overhang(ft)
−1′+
Rake overhang(ft)
−1′+
Gable overhang
Standard rake
The six shapes on the picker, with the selected one's aliases and framing spelled out. The real screen, drawn from the product’s own design system. Sample data — no customer information appears here.
02

Shape and roofing product are two separate choices

A standing-seam gable and a shingled gable are the same shape. Pick the shape, then pick the product — ribbed steel, corrugated, lap-sealed, snap-lock or mechanical standing seam, or shingles — and the panel count comes from that product's own coverage width. Standing seam skips the screw count and adds seam clips instead. Shingles are bought by the square and bring an OSB deck line with them.

03

Each shape brings its own trim onto the order

A hip gets hip caps and a mitered eave frame in place of rake trim, a gambrel gets a bent break cap where the pitches change, and a mansard gets curb trim right around the break. A monitor gets headwall flashing where each wing roof dies into the clerestory riser, billed by the run. These are exactly the pieces that go missing when a shape is quoted off a gable template.

04

Span ceilings for the shapes that have them

A gambrel is 20 foot minimum, typical to 48, with a hard ceiling at 60 — and between the two it is flagged special order rather than refused, because a 55 foot gambrel is a real order that just is not a stock one. Hip is capped at 70 foot and needs a plan at least as long as it is wide. Past roughly 40 foot of span a mono truss gets deep enough at the high end to be engineered territory, and it says so before you quote it.

05

A single-slope back wall stays a wall, not a cliff

The eave height you name stays the low eave and the high wall derives from it, with pitch, eave height and width resolved together so no combination pushes the high wall past what anyone builds. Pitch tops out at the trade's 4/12. Wall steel groups by real run height, the high side gets eave trim in place of a ridge cap that does not exist, and corner trim on those corners runs all the way to the high eave.

06

A monitor barn is three roof systems, and it counts all three

A raised centre gable standing on full-height interior columns — not stub posts sitting on the wing trusses — with clerestory riser walls between the roof levels, its own eave assembly and fascia, corner trim that wraps the clerestory corners as an L like the main level does, and transition flashing where each wing roof meets the riser. The interior column lines get the same footings and poured collars as the wall posts.

How it works
  1. 1Pick a shape from the panel or by right-clicking the roof.
  2. 2The engine branches every stage — wall heights, trusses, purlins, skins, trim, validations and the takeoff — off the chosen shape.
  3. 3Shape-specific spec fields appear with it (mansard break offset, monitor centre width, clerestory height, wing pitch), each with its own drag handle riding the geometry it drives.
  4. 4A shape whose geometry has not landed raises roof.typePending rather than quietly drawing a gable behind a different label.
Why we built it

Roof shape and roofing product are separate decisions — a standing-seam gable and a shingled gable are the same shape — and collapsing them into one list means a builder cannot price the combination they actually sell. The two are chosen independently. Where a shape is not yet fully modelled the tool says so on screen instead of drawing an approximation, because a picture that quietly disagrees with the material list is worse than no picture.

The problem
  • Design tools that only model one roof shape.
  • Selling a shape the estimating tool silently prices as a different one.
Sound familiar?
What you get
Six shapes quotable from one tool.
Each shape's framing and material package is catalogued, not improvised.
The model tells you when a shape is not yet drawn instead of lying.
What's inside
Gable
The default post-frame roof: two planes to a ridge, gable trusses at each end, 2x6 gable studs in the triangle, rake and eave trim.
Monoslope
One roof plane from a low eave to a high eave, with taller posts on the high wall, high-side eave trim instead of a ridge cap, and hard caps so the high wall never becomes a cliff.
Gambrel
The classic barn profile: a steep lower slope breaking to a shallow upper slope at the quarter span, with break trim, four roof faces and factory truss span limits enforced.
Hip
All four sides slope to the walls: hip rafters on the diagonals, jack rafters shortening into the corners, a step-down truss set, a mitered fascia frame and hip caps instead of rake trim.
Mansard
Steep 21/12 faces on all four sides rising to a curb, then a shallow upper hip over the deck — framed as a portal bent with knee walls and a collar tie.
Monitor
A raised centre gable standing on full-height interior columns over two shed wings, with clerestory walls, its own eave assembly and transition flashing where the wings die into the risers.
Bird's beak and flying gable overhangs
The decorative peak extensions builders sell as an upgrade, drawn in the roof plane and priced from the same profile the model draws.
Roofing system with its minimum slope enforced
Pick the actual roofing product — ribbed steel, corrugated, lap-sealed, snap-lock or mechanical standing seam, or shingles — and the design refuses to go below that product's minimum slope.

See it on your own jobs

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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