What is a Skeleton Roof?

A “skeleton roof” is a term used in construction to describe a basic framework of a roof structure before it is fully completed. This framework typically includes the essential structural elements such as rafters, ridge boards, and possibly joists or trusses, depending on the design. However, it does not include the full assembly of all roofing components like sheathing, underlayment, insulation, and the final roofing materials (tiles, shingles, etc.).

Characteristics of a Skeleton Roof

Basic Structure: It comprises the primary supporting elements of a roof but lacks the complete layers that make a roof weatherproof and insulated.
Visible Framework: The skeletal structure of the roof is visible, showing the layout of rafters, beams, and other structural elements.

Building Control and Inspection

Not Subject to Full Building Control Inspection: A skeleton roof might not be subject to the same level of building control inspection as a completed roof. This is because it is not considered a finished structure.
Reasoning: The key reason is that the skeleton roof is an incomplete part of the construction process. Building control typically inspects completed structures or significant milestones in the construction process to ensure compliance with safety standards, building codes, and regulations.
Future Inspections: Once the roof is completed with all its components, it will then be subject to the usual building control inspections. These inspections will check for compliance with insulation requirements, waterproofing, structural integrity, and other relevant standards.

Important Considerations

Temporary State: A skeleton roof is a temporary phase in the construction of a roof. It is expected that the roof will be completed with all necessary components to ensure safety, durability, and compliance with local building codes.
Safety Risks: Even though a skeleton roof is not fully inspected, it’s essential to construct it properly as it forms the basis for the rest of the roof structure. Poorly constructed skeleton roofs can lead to structural failures or issues once the roof is completed.

Structural Details for Birds Mouth

It is not necessary to cut the Birds Mouth to be snug against the top plate.

Think about it. Rafter forces want to push downward or outward, not inward. If the rafters were not fastened to the top plate (discounting structural ridge, ceiling joists, collar ties, etc.) the heel cut of the Birds Mouth would want to go outward, not inward. Shimming gaps in the heel cut will not strengthen the structure.

The heel cut is measured guide for accuracy to help guide roof into it’s right location before fixing without it makes the roof ungulate, but not structural.

Conclusion

In conclusion, a skeleton roof refers to the basic, unfinished framework of a roof. While it might not be subject to the full scope of building control inspections in its incomplete state, it is crucial to construct it correctly and safely as it forms the foundation for the completed roof. Once the roof is fully built, it will undergo the standard inspections to ensure it meets all required building standards and regulations.