Lookout (architecture)

A lookout,[1] lookout rafter or roof outlooker[2] is a wooden joist that extends in cantilever out from the exterior wall (or wall plate) of a building, supporting the roof sheathing and providing a nailing surface for the fascia boards. When not exposed it serves to fasten the finish materials of the eaves.

Construction and placement

A lookout (also called an outlooker or outrigger) is a horizontal framing member that extends from the end of a rafter to the exterior wall and supports soffit-facing materials.[3]

In gable-roof construction, outlookers are typically 2x4 or 2x6 members installed across the tops of the gable truss or rafter and extended outward to carry the fascia board along the edge of the overhang.[4] The overhang framing transfers loads from the roof edge back into the roof framing and is used as an alternative to ladder framing for deeper gable overhangs.[5]

Two common methods of framing gable roof overhangs are ladder framing and outrigger framing. Ladder framing consists of two parallel members connected by short blocks and is typically limited to shorter overhangs of 8 to 12 inches.[6] Another method uses lookout blocks to connect the barge or fly rafter back to the gable framing; according to Simpson Strong-Tie, this ladder method is less wind-resistant and is limited in published literature to a 12-inch overhang.[7] The same source states that cantilevered outlookers are permitted to extend up to 24 inches, whereas ladder outlookers are limited to 12 inches.[8]

References

  1. ^ PBS Glossary - Framing - Lookout
  2. ^ Definition-of.com Dictionary definition of roof outlooker
  3. ^ "City of Eau Claire Municipal Code, Chapter 16.04.050: Definitions". City of Eau Claire, Wisconsin. Retrieved 2026-03-12. "Lookout" means the horizontal framing member extending from end of rafter to exterior wall of building, and which supports soffit-facing material.
  4. ^ "Framing of Gable Roof Overhangs". Building America Solution Center, U.S. Department of Energy. Retrieved 2026-03-12. Outrigger framing, using outlookers, is recommended for overhangs greater than 12 inches deep.
  5. ^ "Framing of Gable Roof Overhangs". Building America Solution Center, U.S. Department of Energy. Retrieved 2026-03-12. Outriggers, which may be 2x4 members or 2x6 members, are then installed on top of the gable truss or rafter so that they butt up against the truss or rafter next to the gable truss and extend outwards to support a fascia board along the edge of the overhang.
  6. ^ "Framing of Gable Roof Overhangs". Building America Solution Center, U.S. Department of Energy. Retrieved 2026-03-12. Ladder framing is typically limited to shorter overhangs of 8 to 12 inches.
  7. ^ Shackelford, Randy (2016-09-30). "Designing Gable End Overhangs". Simpson Strong-Tie. Retrieved 2026-03-12. With this technique, lookout blocks are used to connect the barge or fly rafter back to the gable framing. ... This method is less wind-resistant, and in literature is limited to a 12" overhang.
  8. ^ Shackelford, Randy (2016-09-30). "Designing Gable End Overhangs". Simpson Strong-Tie. Retrieved 2026-03-12. Cantilevered outlookers are permitted to extend out up to 24 inches, while the ladder outlookers are only permitted to extend out 12 inches.
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