Jim Rogers owns and operates Jim Rogers Sawmill and Jim Rogers Timber Designs in Georgetown, Massachusetts, and is active with Vintage Tool NE. Jim Rogers Timber Design assists owner builders with detailed, dimensioned drawings of their project frame. The company uses state of the art 3-D CAD drawing software. They also offer CAD software training, and […]
This is an exploded view of a king post’s bottom tenon where it goes through a very large tie beam. The king post tenon is secured with pegs into the tie beam. A king post hangs down from two rafters and usually has some struts going from the king post up to the two rafters […]
This timber detail exploded view is of a collar beam which is a 4×4 connecting to a 4×6 rafter. The pitch is 12/12, and the tenon is set off the reference face 1 1/2″ and then 1 1/2″ thick, with a 3/4″ hardwood peg.
Here is an exploded view of a pair of purlin joints where they meet the rafter. Each frame design should be reviewed by an experienced timber framing engineer for the exact design of this joint. Loads, spans, type of wood, and possibly other factors will have to be considered when designing this joint. My examples are […]
Here is an exploded view of a birds mouth rafter foot where it meets the plate. A typical timber frame joint where a rafter meets a plate is called a birds mouth and this is a great isometric rendering of this type of joinery.
This is an exploded view of a tongue and blind mortise at the ridge. The rafters are again 4×6 at 12/12 pitch with a 1 1/2″ tenon and mortise with a 3/4″ peg. The mortise doesn’t go all the way through the rafter and it doesn’t go all the way to the top end. This […]
This joint is known as a “step lap rafter tail” and the joint in the plate is known as a step lap rafter seat. I believe it gets it name as the tail laps over the plate which creates an overhang to shed the rain water away from the side of the building. And that […]
This joint is known as the tongue and fork joint. Here is an exploded view of two 4×6 rafters at 12/12 pitch with 1 1/2″ tenon set 1 1/2″ off the reference side with a 3/4″ oak peg. These rough sawn rafters have also been reduced down to the next smaller 1/2″ in size at […]
The most basic scarf for joining two timbers together is the basic half lap joint. One timber has half its depth cut away on the top and one timber has half its depth cut away on the bottom and these two pieces lap over each other. This is an exploded view of a simple half lap […]
Another scarf joint that I have used is the “bladed timber frame scarf joint”. This drawing is of a 6″ x 10″ bladed scarf joint that we cut to create one long timber for an addition to an existing barn. The scarf is 2′ long and the tenons are 2 1/2″ thick and 4″ long. […]