I’ve really struggled with the roof design. We built the main structure and then had to work out how to attach the tiles. While we worked that out we decided to add a timber paneling ceiling. This means we can hide some modern insulation in the roof.
The books I have don’t really talk about how to attach a roof covering. We were planning to use commercial roof tiles until we made our own ceramic tiles, so we need to hang the tiles on battens. I needed to know how the battens were attached to the structure when they were perpendicular to the purlins and what supported that skinny wood when the roof trusses were 1m apart? Work paused while I did other things and let my back brain sort it out. The kitchen frame looks like this;
Then I worked it out – we need a roof structure, in addition to the main structure. In the photo below, you can see the main frames and the large purlins stopping the frame from racking. On top of the purlins are “common” rafters with the battens on top of that. Diagrams of timber frames typically don’t show the roof structure, so I’ve had to look at photos like this one instead.
Next week, we’ll add the insulation, new rafters and battens. Just as soon as we work out what roofing material we’re using, so we know the batten spacing to use. I see a lot of birdsmouth joints in my future.
Unless we do this instead;
Lovely presentation of roof frame types and their dendrodates. http://www.vag.org.uk/conferences/winter2012/bob-meeson.pdf