--- title: "Terms used in a pitched roof" subject: "Building Technology" chapter: 4 key: "semester_6/building_technology:roof-terminology" source: https://www.bctengineer.com/q/semester_6/building_technology/roof-terminology site: BCT Engineering --- # Terms used in a pitched roof Building Technology · Chapter 4: Roofs - Asked in: 2079 Jestha, 3 marks; 2078 Chaitra, 3 marks; 2078 Poush, 7 marks; 2073 Bhadra (asked 4 times) - Video: [Technical Terms in Pitched Roofs | 1.Pitched Roof | Types of Roofs | Building Construction](https://www.youtube.com/watch?v=SzNYv2IKXBE) — SGK Online Education - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_6/building_technology/roof-terminology - Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-4 ## Question Define the terms used in a pitched roof (ridge, hip, purlin, rafter, rise, eaves, battens) with suitable figure. ## Short answer Key pitched roof terms: ridge (top horizontal line), hip (external inclined angle), valley (internal inclined angle), eaves (lower projecting edge), purlin (horizontal member supporting rafters), rafter (inclined member from eaves to ridge), batten (thin strips for tile fixing), rise (vertical height to ridge), span (horizontal distance between supports), pitch (rise/span ratio), gable (triangular end wall), wall plate (load distributor), tie beam (resists outward thrust), verge (gable edge), and cleat (prevents purlin sliding). ## Answer #### Terms used in a pitched roof - **Ridge:** the horizontal line at the top where two sloping surfaces meet. - **Hip:** the inclined line (external angle) where two adjacent sloping surfaces meet; the hip rafter runs along it. - **Valley:** the inclined line (internal angle) where two slopes meet to form a depression; it drains water. - **Eaves:** the lower edge of the roof that projects beyond the wall face to throw water clear of the wall. - **Purlin:** a horizontal member running parallel to the ridge across the principal rafters/trusses, supporting the common rafters. - **Rafter:** an inclined member running from the eaves to the ridge on which battens or boarding are fixed (common rafter, principal rafter, hip rafter, jack rafter). - **Batten:** a thin wooden strip fixed over the rafters on which tiles or slates are hung or sheets are fixed. - **Rise:** the vertical height from the wall plate (eaves) to the ridge. - **Span:** the clear horizontal distance between the supports (inner faces of walls). - **Pitch (slope):** the ratio rise/span, or the angle of the slope with the horizontal. - **Gable:** the triangular portion of the end wall between the sloping edges. - **Wall plate:** a timber/RCC member laid on top of the wall to spread the load of the rafters or trusses. - **Tie beam:** a horizontal member joining the feet of the rafters to resist the outward thrust. - **Verge:** the edge of the roof at the gable end. - **Barge board / fascia:** a board fixed along the verge/eaves for appearance and protection. - **Cleat:** a small block fixed to the principal rafter to prevent the purlin from sliding. #### Figure ```text ridge /\ / \ <- rafter rise -> / \ / \ eaves ->_/________\_<- eaves wall plate wall |<-- span -->| ``` ```text PLAN OF A HIPPED ROOF (L-shaped) +-----------------------+ |\ ridge /| | \_________________/ | <- eaves (all round) | / \ | |/ hip hip \| +--------+ /--------+ | \ / valley | \/ | | |ridge | | | +-------+ ``` The **hip**, **valley**, **ridge** and **eaves** are lines on the roof surface; **rafters**, **purlins** and **battens** are the frame members that carry the covering. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. Ridge is? A. Internal angle B. Vertical wall C. Lower edge D. Horizontal line where two slopes meet at top Answer: D. Top horizontal line. (Key point: Ridge) 2. Hip differs from valley because? A. Same B. Hip is horizontal C. Valley is at top D. Hip is external angle, valley internal depression Answer: D. Hip projects; valley drains water. (Key point: Hip vs valley) 3. Purlin is? A. Thin strip B. Wall timber C. Inclined member eaves to ridge D. Horizontal member parallel to ridge supporting common rafters Answer: D. Rafters carry load to purlins. (Key point: Purlin) 4. Rise is? A. Slope angle B. Horizontal distance C. Eaves projection D. Vertical height from wall plate to ridge Answer: D. Pitch is rise/span. 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