I wish to build a single story rectangular building with a long eave overhang plus a hip and valley roof. This will be a primer before building a house using the same design on a bigger scale. I have read a number of timber framing books and searched the net, but have not found a frame design that covers frames suitable for hip and valley. Can anyone help provide info on an optimal frame design? Even very basic practicalities such as where to position the posts is appreciated. A little about the structure:

Outer building dimensions not including eaves: 3.5m x 2.5m

Eave overhang on every side: 1m

Roof pitch: 17 degrees or greater

Roof weight: 70kg/sqm (clay tile)

Location: Thailand (warm-hot year round)

Welcome to the forum.
Can you post a picture or a link to a picture of what you want to build?

Thank you Jim, glad to find this forum. Looking from the top down it would look like this. The faint purple rectangle in the center is the outer wall perimeter. The reason for the long eave overhang is to help keep the walls dry which will be earth plastered leichtlehm (straw-clay).

What kind of winds (every-day, seasonal, monsoon) do you get in your part of Thailand? It looks like a very top heavy design, esp w tile roofing. How will you anchor the blding to foundation and ground, and roof to walls? Can you plant any windbreaks?
When you build the larger house with the same amount (1 meter) roof overhang the mass of the bulding will be proportionatly larger and provide better stability.
Oh, I see you're an engineer so you probably know this.
Steve

Canopy,

I see your plan view, but I am having trouble understanding the frame you intend. As of right now you have two different pitches. Have you thought about creating an equal pitch on all four roof planes, thereby shortening your ridge. It make the work easier especially and then lets your hip land on a building corner as opposed to some point on the plate. In your plan that you have right know what is holding you hip up? Am I missing something?

Try placing your hips 45 degrees to your eaves and see what happens.

Compound joinery (your hip roof framing) is not something that can be quickly explained. As Mo stated, if the hips run at 45 degrees in plan (what's called a regular hip) it becomes a whole lot easier. Stick framing regular hips is very easy. Timber framing regular hips adds some complications, and irregular hips adds even more.

There has been quite a bit written on compound joinery. Look for info on the Hawkindale angles on the TFG website, articles by Will Beemer in the Timber Framing Magazine, old books on steel squares (Siegle's?), A Roof Cutter's Secrets by Holliday, and various texts written in German, French, and Japanese.

Good luck, and feel free to ask more questions.

My hope was someone has made a hip & valley frame and I could see it and use it as a basis for my needs. While I do have an engineering background and parts of it should help, it is mainly non-structural so I do not wish to recreate the wheel with limited skills. Before I give up and use a traditional bent frame with no hip and valley, I thought I would share a sketch showing the problem I have which is a very complex joint at the ends of the ridge beam.



The other part about using equal pitches sounds appealing, but does not fit easily. Either it changes the geometry of the roof or it probably needs a much beefier post arrangement. Don't worry about the red tank, it's just a place marker to have appropriate clearance for a passive solar water heater.

Hi Canopy,

What is the dimension from the centerline of kinpost to centerline of kingpost in plan?

Hi Canopy,
Your frame is explained very clearly (I hope) in my last article on compound joinery in Timber Framing #92, June 2009. There are photos and drawings of almost your exact conditions, and directions for figuring the various plate heights, hip offsets and angles.

Mo, the distance is 2.1M.

Will B, that sounds very helpful. A just ordered a copy along with Jack Sobon's well renowned book.