Roof Components

Summary

This video provides a detailed walkthrough of the main components involved in building a Broken Hip and Valley roof. It explains the key elements such as the ridge, common rafters, crown end rafters, hips, valleys, creeper rafters, and valley creepers. The video also covers purlins, struts, and strutting beams, which offer structural support in larger roof spans. Through clear explanations, viewers gain an understanding of how these various elements come together to form a strong, functional roof. This insightful guide is applicable to most roofing projects.

Takeaways

• 😀 The ridge of the roof is the highest member, level, and runs parallel to the external walls.
• 😀 The roof features both a major and minor span, each having its own ridge.
• 😀 Common rafters are used for both major and minor spans, running at 90 degrees to the external walls and connecting to the ridge.
• 😀 Crown end rafters are similar to common rafters but slightly shorter due to the intersection at the ridge.
• 😀 Hips bisect the external corners at a 45-degree angle and connect with the common and crown end rafters.
• 😀 Valleys run from internal corners of the wall plates, serving a similar function to hips but in different locations.
• 😀 Creeper rafters (or jack rafters) intersect with hips, not the ridge, and are cut to fit into the hip at a specific angle.
• 😀 A Broken Hip occurs when the roof's hip intersects with a minor span area and does not extend fully.
• 😀 Valley Creepers fill the space between the ridge and the valley, while Cripple Creepers are cut to connect hips and valleys.
• 😀 Purlins provide additional support for rafters spanning large distances, often supported by struts transferring the load to the wall plate.

Q & A

What is the main topic of the video?

The video focuses on explaining the key components of a Broken Hip and Valley roof construction, including the various rafters, struts, and purlins involved.

What is the purpose of the ridge in a roof structure?

The ridge is the highest member of the roof, running parallel to the external walls. It serves as the point where the rafters meet and supports the weight of the roof.

What distinguishes a crown end rafter from a common rafter?

A crown end rafter is similar to a common rafter but is slightly shorter due to the shortening effect caused by the intersection at the ridge.

How do hips function in roof construction?

Hips bisect the external corners of the roof at 45-degree angles and run up to where the common rafters and crown end rafters meet.

What is the role of valleys in roof design?

Valleys are similar to hips but run from internal corners of the roof, helping to channel rainwater and providing structural support at these junctions.

What are creeper rafters (jack rafters)?

Creeper rafters (or jack rafters) run at 90 degrees to the external walls, but instead of meeting the ridge, they intersect with the hips. They are cut with a special creeper cut to fit into the hip.

What is the purpose of a Broken Hip in roof construction?

A Broken Hip occurs where the ridge line is interrupted due to an intersection with a minor span, leading to a discontinuous roofline. It helps to transition between different sections of the roof.

What are Valley Creepers and Cripple Creepers?

Valley Creepers are rafters that fit into both the ridge and valley sections of the roof. Cripple Creepers are similar but are cut with plumb and bevel cuts, fitting into both the hip and valley.

When is a purlin necessary in roof construction?

A purlin is used when rafters span a large distance and require additional support. It is typically placed at mid-span to support the rafters, and it is supported by struts that transfer the load to the wall plates.

What is the difference between Fan Struts and Straight Struts?

Fan Struts have a fan-like shape and provide support to purlins by transferring their load to the wall plates. Straight Struts are simply straight beams that serve the same purpose of transferring load to the wall plate.