Power Point Presentation Unit 49 Intersecting Roofs with

Power. Point® Presentation Unit 49 Intersecting Roofs with Equal Spans • Intersecting Roofs with Unequal Spans • Valley Rafters • Valley Jack Rafters • Hip-Valley Cripple Jack Rafters • Constructing Intersecting Roofs

Unit 49 — Intersecting Roofs In this intersecting roof, the hip section over the garage at the right intersects with the main gable roof.

Unit 49 — Intersecting Roofs For intersecting roofs with equal spans, both sections are the same width and both ridge boards are the same height.

Unit 49 — Intersecting Roofs For intersecting roofs with unequal spans, the intersecting ridge board is lower on the section with the smaller span.

Unit 49 — Intersecting Roofs Side cuts at the seat of a valley rafter must be angled back at the heel plumb cut line to allow the rafter to drop down into the inside corner of the building.

Unit 49 — Intersecting Roofs Valley rafters require side cuts at the seat and tail of the overhang.

Unit 49 — Intersecting Roofs Valley rafters require angled side cuts at the ridge, heel, and tail.

Unit 49 — Intersecting Roofs An intersecting roof with unequal spans has a supporting valley rafter and a shortened valley rafter.

Unit 49 — Intersecting Roofs A shortened valley rafter runs at a 90° angle to the supporting valley rafter. Shortened valley rafter length is based on the run of the minor roof section.

Unit 49 — Intersecting Roofs A shortened valley rafter has a square cut where it butts against the supporting valley rafter.

Unit 49 — Intersecting Roofs Angled side cuts are required at the heel plumb line. Angled tail cuts may also be needed.

Unit 49 — Intersecting Roofs Valley jack rafter lengths can be calculated from the longest jack rafter at the inside corner of the building. In this example, the roof has a 9² unit rise and the rafter spacing is 24² OC.

Unit 49 — Intersecting Roofs Valley jack rafter lengths can be calculated when spacing begins from a common rafter positioned away from the inside corner. In this example, the roof has a 9² unit rise and the rafter spacing is 24² OC.

Unit 49 — Intersecting Roofs Valley jack rafter lengths can be calculated when spacing begins from the center point of intersecting ridges. In this example, the roof has a 4² unit rise and the rafter spacing is 16² OC.

Unit 49 — Intersecting Roofs A valley jack rafter has a square cut where it fits against the ridge and a side cut where it meets the valley rafter.

Unit 49 — Intersecting Roofs Framing square rafter tables may be used to calculate the length of hip‑valley cripple jack rafters. In this example, the roof has a 6² unit rise. Additional information required is the distance from the end of the main section to the intersecting roof section. This distance, shown as length A-C on the drawing, is 4¢‑ 0².

Unit 49 — Intersecting Roofs A hip‑valley cripple jack rafter has a plumb cut and side cut at each end.

Unit 49 — Intersecting Roofs A valley cripple jack rafter is always twice the length of the valley jack rafter. Note that the valley cripple jack rafter and the valley jack rafter meet at the same point on the shortened valley rafter.

Unit 49 — Intersecting Roofs The run of a valley cripple jack rafter is twice the run of the valley jack rafter that it meets at the shortened valley rafter. Side cuts on valley cripple jack rafters run in opposite directions.

Unit 49 — Intersecting Roofs The ridge board intersecting a hip roof in which the two roof sections have unequal spans fits into the corner formed by the supporting and shortened valley rafters.

Unit 49 — Intersecting Roofs To locate the center point of a ridge board intersecting a gable roof, add the distance between the end of the main roof and side of the intersecting roof to the run of the intersecting roof. The center point of a ridge board intersecting a hip roof in which the two roof sections have equal spans must be located accurately.

Unit 49 — Intersecting Roofs When calculating the length of an intersecting ridge board when a gable roof intersects with the main roof, onehalf the thickness of the main ridge board is subtracted from theoretical length.

Unit 49 — Intersecting Roofs The procedure is shown for calculating the length of the intersecting ridge board when a hip roof intersects with the main roof and when the two sections have equal spans.

Unit 49 — Intersecting Roofs The procedure is shown for calculating the length of an intersecting ridge board when a gable roof intersects with the main roof and when the two sections have unequal spans.

Unit 49 — Intersecting Roofs When framing an intersecting roof with equal spans, the main ridge board is set at the proper height and supported with the end common rafters. In this example, both sections of the intersecting roof are gable roofs.

Unit 49 — Intersecting Roofs When framing an intersecting roof with unequal spans, the main ridge board is set at the proper height and supported with the hip rafters and common rafters at each end. In this example, one section of the intersecting roof is a gable roof and the other section is a hip roof.

Unit 49 — Intersecting Roofs Blind valley construction does not require valley rafters.

Unit 49 — Intersecting Roofs The valley jack rafters for blind valley construction require a seat cut combined with a side cut where the rafters fasten to the 1 × 6.