An example of Principal rafter and common purlin timber frame configuration with timbers and parts labelled.

Anatomy of a simple timber frame

[glossary_exclude] [/glossary_exclude] The principal rafter and common purlin system The first in a series of articles exploring some common types of timber frame configurations. Considered a modern style of timber framing, the principal rafter and common purlin system has several advantages that beginner timber framers will appreciate. The joinery is, on a whole, simpler than in a common rafter system.