from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. One of several horizontal timbers supporting the rafters of a roof.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A longitudinal structural member bridging two or more rafters of a roof.

from the GNU version of the Collaborative International Dictionary of English

  • n. In root construction, a horizontal member supported on the principals and supporting the common rafters.

from The Century Dictionary and Cyclopedia

  • n. In carpentry, a piece of timber laid horizontally upon the principal rafters of a roof to support the common rafters on which the covering is laid. Also called side timber or side waver. See cut under roof.


Middle English.
(American Heritage® Dictionary of the English Language, Fourth Edition)
Information on the origin of the term is scant at best. According to Websters it comes from the 15th century English. According to the Oxford Concise Dictionary, it is "Middle English, perhaps of French origin". All other sources referenced Middle English or 15th Century English. (Wiktionary)


  • For the roof we will require a ridge against the wall of the dwelling house, sash-bars running at right angles to this, a "purlin," or support, midway of these, and a sill for the lower ends.

    Gardening Indoors and Under Glass A Practical Guide to the Planting, Care and Propagation of House Plants, and to the Construction and Management of Hotbed, Coldframe and Small Greenhouse

  • I got up, and holding tightly to the purlin — for the waves made the masts tremble with their violence — I tried to look around and below me.

    The Survivors of the Chancellor

  • One of the main disadvantage of the truss is that the strength and stability of its elements is to be designed by an engineer while the other roof structures, especially the purlin roof, can be built by carpenters and steel workshops themselves.


  • The purlin roof consists of both rafters and purlins.


  • Material input low, but requires connectors, fasteners high (requires rafters, posts, struts, purlins and battens) less material input than for purlin roof


  • The static system of the roof structure as a whole is then no longer a truss but can be a purlin roof (see Section 2.3), a double-hinged arch or bent.


  • The bay of these 7 × 15 section angelica wood joists has an inter-axis of 56.7 cm and 47 cm on either of the bracing tie-beam of the roof structure; this tiebeam forms part of the joist system and takes up the purlin brackets of the roof overhang of the gutter roofs.

    Chapter 7

  • Eaves purlin anchored to the ring-beams on waiting rods laid during the pouring of the ringbeam.

    Chapter 7

  • Around the top of the walls a reinforced concrete ring-beam in a lost formwork of earth blocks also serves to anchor the eaves purlin on which restes the lower edge of the steel roofing sheets which then extende beyond the wall.

    Chapter 7

  • The attachment of the lower edge of the roofing sheets is reinforced at the level of the eaves purlin, which lays on the top of the verandah posts 'at the end of the ring-beam, by 6 mm diameter rods laid during the pouring of the ring-beam concrete which are then bent round the eaves purlin.

    Chapter 7


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  • I like a good purlin in me ceilin', darlin'.

    February 25, 2016

  • "She and Ulf were alone on a bed in a room, and she was looking up at the timber beams and purlins of a ceiling she'd seen before."
    Mistress of the Art of Death by Ariana Franklin, p 342 of the Berkley paperback edition

    February 28, 2012