roof framing

Wood Frame Construction

ROOF FRAMINGTerms

Shapes/StylesFraming ConditionsRoof Pitch/Slope

Professor Richard luxenburg AIADepartment of Architecture and Interior DesignAnne Arundel Community College

Buckwalter Hoouse, PAHugh Newell Jacobsen, Architect

GABLE Triangular part of the wall under each end of a roof

gablegablerake boardrake board

VALLEY Low points formed by the intersection of two roof slopes (forming a trough to direct

water). Formed by valley rafters Diagonal rafter that supports the valley intersection

DORMER Structure protruding through the

plane of a sloping roof Has its own roof structure A small secondary roof structure

RIDGETop part of gable or hip roofsArea where rafters meet ridge board Where the roof “folds” over the top

Framing a Roof Opening for a Dormer• DOUBLE HEADER RAFTERSDOUBLE HEADER RAFTERS• DOUBLE TRIMMER RAFTERDOUBLE TRIMMER RAFTER

Roof Terminology

EAVE Flat, horizontal edge at the

low side of a sloping roof Gutter placement

Consists of: FASCIA BOARD

Edge board under roof structure following slope

SOFFIT Undersurface of roof overhang

SOFFIT VENT Opening in soffit under eave to

allow air to flow into attic or area below roof sheathing

Eave - Horizontal roof edge

Rake - Sloping roof edge

Terminology

Metal Drip Edge

Soffit• Wood• Metal• Plastic

Gutter

Fascia

Eave Detail

Rake and Eave Connections

Detailing the Abbreviated Eave & Rake Cornice

A ladder of lookouts supports and provides a nailing surface for a boxed-in

rake.SMALL OVERHANG

LARGE OVERHANG

Soffit Details

ROOF SHAPES & STYLES

FLAT minimal slope ¼” per foot

SHED ( or mono-pitch)

slopes in one direction slope can vary

ROOF SHAPES & STYLES

GABLE Slopes in two directions Rafters (or truss) meet at top peak to a

ridge board

HIP slopes in four directions slope is constant on all sides

RIDGE CONNECTIONS

Gable RoofGable Roof

Hip RoofHip Roof TerminologyTerminology

GAMBREL Like gable, but has two different

pitches

MANSARD Gambrel and hip (or flat) combined

These styles require knee walls and ceiling joists

ROOF SHAPES & STYLES

LEAN-TO ROOF SHED MEETING A WALL

FLAT ROOFFLAT ROOFOVERHANGOVERHANG

CONDITIONSCONDITIONS

Roof Trusses

Valleys in Trussed Roofs

ABBREVIATED EAVE FRAMED WITH TRUSSES

BOXED-IN TOP CORD OF TRUSS

EXTENDED TOP CORD

WITH SOFFITED EAVE

Cornice Details using Roof Trusses

ROOF SHEATHING or DECKING

No SHEATHING with diagonal bracing for use with wood shingles and shakes

Plywood Clip:Plywood Clip:

To prevent separation of roof sheathing at mid To prevent separation of roof sheathing at mid span between rafters or trusses Also allows span between rafters or trusses Also allows moisture expansion of the sheathing; typically 1/8” moisture expansion of the sheathing; typically 1/8” spacing between panelsspacing between panels

Roof Slope and Pitch

Pitch as a: Ratio of vertical to horizontal.

For example, a roof that rises 6 inches (or feet) for every 12 inches (of feet) of horizontal run has a 6/12 pitch.