powerpoint ® presentation unit 49 intersecting roofs intersecting roofs with equal spans...

28
PowerPoint ® Presentation Unit 49 Intersecting Roofs Intersecting Roofs with Equal Spans • Intersecting Roofs with Unequal Spans • Valley Rafters • Valley Jack Rafters • Hip-Valley Cripple Jack Rafters • Valley Cripple Jack Rafters • Constructing Intersecting Roofs

Upload: kaylie-juby

Post on 16-Dec-2015

301 views

Category:

Documents


3 download

TRANSCRIPT

PowerPoint® PresentationPowerPoint® Presentation

Unit 49Unit 49Intersecting RoofsIntersecting Roofs

Intersecting Roofs with Equal Spans • Intersecting Roofs with Unequal

Spans • Valley Rafters • Valley Jack Rafters • Hip-Valley Cripple Jack

Rafters • Valley Cripple Jack Rafters • Constructing Intersecting Roofs

Intersecting Roofs with Equal Spans • Intersecting Roofs with Unequal

Spans • Valley Rafters • Valley Jack Rafters • Hip-Valley Cripple Jack

Rafters • Valley Cripple Jack Rafters • Constructing Intersecting Roofs

Unit 49 — Intersecting RoofsUnit 49 — Intersecting Roofs

In this intersecting roof, the hip section over the garage at the right intersects with the main gable roof.

In this intersecting roof, the hip section over the garage at the right intersects with the main gable roof.

Unit 49 — Intersecting RoofsUnit 49 — Intersecting Roofs

For intersecting roofs with equal spans, both sections are the same width and both ridge boards are the same height.

For intersecting roofs with equal spans, both sections are the same width and both ridge boards are the same height.

Unit 49 — Intersecting RoofsUnit 49 — Intersecting Roofs

For intersecting roofs with unequal spans, the intersecting ridge board is lower on the section with the smaller span.

For intersecting roofs with unequal spans, the intersecting ridge board is lower on the section with the smaller span.

Unit 49 — Intersecting RoofsUnit 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.

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 RoofsUnit 49 — Intersecting Roofs

Valley rafters require side cuts at the seat and tail of the overhang.Valley rafters require side cuts at the seat and tail of the overhang.

Unit 49 — Intersecting RoofsUnit 49 — Intersecting Roofs

Valley rafters require angled side cuts at the ridge, heel, and tail.Valley rafters require angled side cuts at the ridge, heel, and tail.

Unit 49 — Intersecting RoofsUnit 49 — Intersecting Roofs

An intersecting roof with unequal spans has a supporting valley rafter and a shortened valley rafter.An intersecting roof with unequal spans has a supporting valley rafter and a shortened valley rafter.

Unit 49 — Intersecting RoofsUnit 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.

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 RoofsUnit 49 — Intersecting Roofs

A shortened valley rafter has a square cut where it butts against the supporting valley rafter.

A shortened valley rafter has a square cut where it butts against the supporting valley rafter.

Unit 49 — Intersecting RoofsUnit 49 — Intersecting Roofs

Angled side cuts are required at the heel plumb line. Angled tail cuts may also be needed.

Angled side cuts are required at the heel plumb line. Angled tail cuts may also be needed.

Unit 49 — Intersecting RoofsUnit 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 9 unit rise and the rafter spacing is 24 OC.

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 9 unit rise and the rafter spacing is 24 OC.

Unit 49 — Intersecting RoofsUnit 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 9 unit rise and the rafter spacing is 24 OC.

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 9 unit rise and the rafter spacing is 24 OC.

Unit 49 — Intersecting RoofsUnit 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 4 unit rise and the rafter spacing is 16 OC.

Valley jack rafter lengths can be calculated when spacing begins from the center point of intersecting ridges. In this example, the roof has a 4 unit rise and the rafter spacing is 16 OC.

Unit 49 — Intersecting RoofsUnit 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.

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 RoofsUnit 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 6 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 4‑0.

Framing square rafter tables may be used to calculate the length of hip‑valley cripple jack rafters. In this example, the roof has a 6 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 4‑0.

Unit 49 — Intersecting RoofsUnit 49 — Intersecting Roofs

A hip‑valley cripple jack rafter has a plumb cut and side cut at each end.

A hip‑valley cripple jack rafter has a plumb cut and side cut at each end.

Unit 49 — Intersecting RoofsUnit 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.

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 RoofsUnit 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.

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 RoofsUnit 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.

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 RoofsUnit 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.

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 RoofsUnit 49 — Intersecting Roofs

When calculating the length of an intersecting ridge board when a gable roof intersects with the main roof, one-half the thickness of the main ridge board is subtracted from the theoretical length.

When calculating the length of an intersecting ridge board when a gable roof intersects with the main roof, one-half the thickness of the main ridge board is subtracted from the theoretical length.

Unit 49 — Intersecting RoofsUnit 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.

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 RoofsUnit 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.

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 RoofsUnit 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.

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 RoofsUnit 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.

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 RoofsUnit 49 — Intersecting Roofs

Blind valley construction does not require valley rafters.Blind valley construction does not require valley rafters.

Unit 49 — Intersecting RoofsUnit 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.

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.