How to Make a Butterpat Joint

Ben Law
Friday, 18th July 2014

Woodsman Ben Law explains how to use a transfer scribe to make a strong 'butterpat joint' when using roundwood timber frames.

As we head deeper into summer, the flow of courses are becoming more regular at Prickly Nut Wood. My flagship course ‘Roundwood Timber Framing’ is running as I write. I have been teaching this course for 10 years now and during that time have refined and detailed the content. Early courses revolved around basic techniques for joining roundwood, which although strong and effective, they lacked the opportunities of scribing tuition which now forms a key part of all the courses.

The scribing allows the creation of a strong engineer tested joint but with the aesthetic lines of two round poles caressing each others' curves. This joint - I refer to as the ‘butterpat joint’ (for it looks like a pat of butter in a butter dish) -  is the main joint other than a mortise and tenon joint that we use in roundwood timber framing. To scribe the ‘butterpat joint’, I use a Veritas transfer scribing tool. There are many different designs on the market but the Veritas tool is well made with strong brass fittings and can be used with a scribing point and pencil. The key to successfully using the tool is to have an accurate level board set up. The level board is a piece of wood checked to be level in all planes with a vertical line drawn on it.

The compass part of the scribing tool is opened to measure the depth of the scribe you wish to achieve and then offered up to the level board. Both the point and the pencil must touch the vertical line and the twin levels on the scribing tool must be set to be level. This can be a little fiddly, but once set up you are ready to scribe. Providing you keep both bubbles on the scribing tool level at all times while you are scribing, you will create a perfect scribe - the tool always remains true.

One change I have noticed over the last few years is the growing number of international students coming to learn about roundwood timber framing. This year has already seen students from Australia, America, Denmark, India, Italy and Thailand as well as a good number from the UK. It is satisfying to see how these techniques are so globally adaptable. The ability to source timber straight from the woods and construct buildings using hand tools and carpentry rather than sawn lumber and plate connectors clearly has universal appeal.

‘Using what is available around us’ has always been at the forefront of my practice when managing woodlands and constructing buildings. One example of this I enjoy sharing on my courses is the use of chestnut leaves, which when laid within a butterpat joint, identify high points that need further chiselling by staining these points inside the closed joint with chlorophyll. It is truly satisfying to use chestnut leaves when making a frame from sweet chestnut – the whole tree has a use.

Roundwood timber framing utilises small diameter timber which together with good jointing techniques creates unique, bespoke buildings adaptable to all parts of the globe. My own house was built over 12 years ago and the oldest timbers in the frame were built from coppiced chestnut of 28 years of age. In another 16 years I can return to the same trees (coppice stools) and cut another house from the re-growth of the timber in my house. In basic terms the trees are re-growing houses every 28 years and with good maintenance a house like my own could last up to 150 years of age; so the same trees can produce five houses in the lifetime of the one I am living in…sounds like a sustainable solution to me!  

Further resources

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For Roundwood Timber Framing Tools visit 

For more information on Ben Law's courses visit

Roundwood Timber Framing - Building Naturally Using Local Resources for a special price of £14.95 (also available as an eBook and DVD)

How to build a beautiful, energy efficient round home in the woods

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