A roundwood cape from coppiced sweet chestnut and ash...

We're just starting work on a roundwood cape timber frame house, and I thought it'd be good to share the story of our progress here for others interested in doing something similar.

We have a ~10x8m stone cottage with a flat concrete roof somebody put on after rebuilding the cottage from a total ruin in the 70's. The walls are ~1m thick and sturdy, but we don't have much faith in the concrete roof to bear any weight, so we'll be knocking through in a couple of places to place basement poles for the internal sills. After the new story is built, we might bring the concrete roof down from the inside, or we might just knock through for a staircase.

Since we're sourcing all the wood from locally coppiced sweet chestnut, and since we need to handle it all between the two of us, we decided to keep almost all timbers below a length of 4m. The diameters range from about 18cm-25cm for all the principle timbers.

Our first delivery arrived recently and we've been heaving them onto the roof ready to begin work. After months of planning, we're finally just a few days away from marking, cutting, heaving and joining!

Here's a picture of the plans (pictured as squared timber because it's easier to model) and a picture of our sill timbers on the roof ready for marking and cutting!

Hello,

What type of layout method are you using?

Regards,

jay

Because a lot of the larger timbers have irregularities and imperfections which we will have to work carefully to use to their best, their position in the frame is important, and so major frame timbers will all be marked using the scribe rule system - each joint will be individually marked and cut to fit. Since we're cutting and assembling the bents on-site this makes sense anyway. Some of the smaller timbers placed after the frame is raised will be marked using a square rule system so we can cut a lot of identical joints to save us time.

We'll be raising the frame in two raises. First we'll construct the four square bents which comprise the lower half of the house, raise them, and lay a floor from which we can assemble and raise into place the roof trusses. We'll be raising by hand on top of a stone house on the side of a steep hill (and we can't afford to rent a crane) so this is the only conceivable way we can see to accomplish it!

Hi Andru,

I teach several forms of timber framing, and as a member of a design/build group, we work in "live edge" wood and stone on most of our designs as we specialize in vernacular folk styles, especially of the Middle East and Asia.

With live edge material seldom do we use lofting or scribing techniques, and only use "line layout" and "template" methods, as they are not as labor intensive. You can even cut joints in one piece of the frame being in one location, while the other piece is someplace else. There is also much less or no "trial fitting" of the wooden members of the frame. Your project is going to be very labor intensive, I would think, using the scribing methods, as each piece of wood is going to have to be in proximity to the other joining piece, and you are going to need to move them at least 3 times to get a proper fit.

I look forward to following your process.

Regards,

jay

Hi Jay, thanks for the advice. Perhaps I misunderstood your question, or I'm using terms incorrectly. Let me explain some of the techniques we plan on using. If you have any further advice on how we might make our lives easier I'd love to hear it. Likewise, if I'm misusing terminology or misunderstanding concepts, let me know!

We're marking up from a centre line for all timbers. For many of the joints on the primary timbers we'll be squaring faces and using a centre line and templates to mark up. However, we plan to cut and fit each of the joins individually, checking them as we go to ensure a good fit. These primary joints won't be interchangeable; each timber will have a specific place in the frame, and some parts of the join may be scribed so that we are only squaring the surface where one timber meets another. In that sense it's more similar to scribe rule (as I understand it) than square rule, which reduces timbers to a uniform size at the joints in order to make the timbers interchangeable.

We've finished marking up our currently getting ready to cast some concrete plinths on which our sill timbers will sit, since the concrete roof on which we're building is far from level! Once that's done, we're finally onto marking our first sill timbers for cutting, scarfing, and fitting!