Building a Hand-Framed Timber Roof: Step-by-Step Process
(This is the eighth in a 10 part series. Credit: Akribis Leather. Luke Riemer, owner, was the framing contractor we hired for our build. The project consisted of a carriage house, garage extension with suite above, and renovation/expansion of the existing residence. All 3 phases of the project had some timber framing elements. Text below is a cleaned up transcript of the video above)
When it comes to post-to-beam connections, the possibilities are endless. I prefer a hybrid approach: wooden connections using lap joints reinforced with a few timber screws. This method avoids large hangers and saddles, provides a clean look, and allows for quick assembly while showcasing some classic joinery.
In this project, the exterior dimensions of the posts match the beams, but sometimes I like larger posts with a leg running up to lap everything together. Here, the post leg is buried inside the beam connection. A 2 ½” x 2 ½” leg rises into notches in the beams, and timber screws secure everything together. This ensures structural stability, hurricane hold-down protection, and a polished finished look with just the black heads of the screws visible.
Preparing the Timber Work
For the back deck, I’m using glulam beams for posts, beams, king post, and ridge beam. The rafters are 2x8 rough-sawn fir, and the decking will be 2x6 TNG fir with 7/16” plywood on top. All of this has to align with the existing roof.
The first step is figuring: I work from the finished surface down, setting the heights of the sheathing, decking, and beams. This determines post lengths. A mock-up rafter helps calculate plum cuts, seat cuts, and overhangs. With an 18-inch overhang, I factor in fascia thickness to determine the bird’s mouth location.
Because rough-sawn fir varies in height by up to 3/8”, the top plane is non-negotiable. Decking on top is exposed, so I work from the top down to ensure consistency. I measure off the house, mark the bird’s mouth, and set my beam height—crucial for accurate post lengths.
Cutting and Preparing Posts
I cut mirrored posts side by side to ensure symmetry. Starting with the bottom cut, I measure up to set the total height from the bottom of the post to the top of the beam. After accounting for the beam depth, I cut the bearing points.
Cuts are made from both sides for precision. I use a circular saw for exposed edges and a sawzall for internal areas. Any high spots are removed with a chainsaw, leaving a flat, clean bearing surface. Tiny 45° bevels soften the edges for both aesthetic appeal and practical alignment.
The inside legs that will be hidden within the joint are left unroutered since they won’t be visible. Knife plates are used for post-to-deck connections, bolted down for stability, with the post bearing on top of the plate. Heights are verified with a DeWalt laser, ensuring both bearing points are level.
Creating the Beam Joints
For a king post landing on a beam, I cut a 2 ½” deep lap joint. Outer cuts are made with precision, and the center is removed in shallow passes to avoid blowout. The joint is carved flat in the center, and knots are carefully chiseled to ensure a smooth, stable surface.
Preparing Rafters
Rafters are rough-sawn 2x8 fir, varying slightly in depth. To ensure a perfect fit, I built a plywood template with exact bird’s mouth and top rafter cuts. This allows for consistent, accurate markings across all rafters. The top plane is critical as 2x6 TNG decking will sit on it, while slight variations on the underside are negligible.
Rafters are crowned slightly for stability, and the template is transferred carefully for precise cuts.
Assembling the Roof
For post-and-beam connections, lap joints and a few timber screws provide tight hold-down protection without exposed hardware. Rafters are attached with two timber screws each, one on either side of the top, and another through the top into the beam.
The king post fits perfectly into its lap, and the ridge beam seats correctly. Outer rafters sit in the recess, and decorative knee braces and additional structural details will follow. With careful planning and precise cutting, no exterior hardware is required, leaving a clean timber aesthetic.
Conclusion
By carefully planning heights, angles, and joinery, and using a combination of glulam beams, rough-sawn fir, and precise templates, this hand-framed timber roof comes together efficiently and beautifully. Key points for success include:
- Working from finished surface down to set heights
- Cutting mirrored posts simultaneously
- Using templates for precise rafter geometry
- Combining lap joints with selective timber screws
- Verifying levels with a laser
This approach ensures structural integrity, ease of assembly, and a polished, professional finish for any timber-framed roof project.
