Hand-Framing a Complex Roof: Tips for Combining Multiple Pitches and Dormers
(This is the seventh 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)
Working on a hand-framed roof with a mix of 4/12 and 10/12 pitches is always a challenge, especially when you’re dealing with dormers, overhangs, and large beams. Recently, I tackled a project with a massive 4-ply, 1-3/4” by 18” LVL beam carrying the load from the top of a rake wall to a tall stairwell wall. Here’s how I approached it.
Planning and Prepping
Before lifting a single piece, I started on the ground. The first step is always the math—figuring out your non-negotiables and critical dimensions. In this case, the 4/12 pitch sits on top of an 8-3/4” wall, while the roof itself is made of I-joists with strapping and sheathing on top.
The peak intersections need careful planning so the sheathing planes perfectly. I left the cap plate off to allow future additions and tacked the plates down, marking beam pockets and setting the bottom plate.
Unique Dormer Details
This project had a tricky dormer situation: a combination of 10/12 and 4/12 pitches on the same plane. This created a dormer look with stacked walls, meaning the 10/12 fascia protruded off the exterior wall without any cantilever. To handle it:
- I blocked diagonally between studs.
- Ran 2x4 outlooks through the blocking.
- Locked everything in place with additional blocking.
The result is a strong, sturdy assembly. I always sheet the wall before standing it: first the wall itself, then the wing roof, followed by the dormer portion. Everything else builds on top of this base.
Installing Large Beams
Standing a multi-ply LVL beam requires precision. Make sure the beam sits perfectly flat; any curve in the plies will remain once nailed together. Checking the straightness down the edge is critical, and using a slab or stack of I-joists underneath helps keep it flat.
Strapping and Rafter Layout
Before installing I-joists, I lay out top cord lines for 2x4 cross strapping on the ground. This ensures straight placement and makes it easier to snap lines once the joists are lifted. The strapping also ties rafters together, functioning like the spine of a book.
Joist-to-Wall Connections
For slopes of 4/12 or less, I use wedges cut from 4x4s at 18 degrees. These provide proper bearing for the rafters. For steeper slopes, mechanical connections are required. The wedges ensure alignment and stability.
Overhangs and Roof Extensions
Creating overhangs on complex roofs requires some clever engineering:
- Rafter tail extensions are added on the webs.
- Squash blocks support loads at the wall.
- Web stiffeners run into adjustable pitch hangers.
- Toe boards and small rake walls are built to the top of joists to allow strapping to extend for the overhang.
Every piece is measured, cut, and laid out carefully to keep walls, fascia, and strapping straight.
Finishing the Roof
After strapping, the rafters are lifted from pre-built stacks and nailed into place. Cross strapping ties everything together, while sub-fascia and sheathing finish the structure. Safety is essential: rope and harnesses prevent major accidents even if minor injuries happen.
Once the 4/12 pitch is complete, the ridge vent is prepped, the brake wall is installed, and the structure is ready for interior finishing and exterior timber work.
This roof demonstrates how careful planning, precise measurements, and smart framing techniques can make even complex hand-framed roofs manageable. Whether you’re working with multiple pitches, dormers, or massive LVL beams, taking the time to prep and build on the ground pays off in speed, accuracy, and stability on site.
