After a brief hiatus over the Christmas break we are cracking on with our Neolithic House build. Here’s an update from our archaeologist Claire Walton about the latest developments…
Despite Mother Nature’s best attempts to thwart us, the construction project has moved on apace, with the structure looking a lot more like a building now.
We’ve installed the main purlins and the ridge poles which has given us a real sense of the shape of the house. In line with all things Neolithic, we’ve kept it low tech. That means installing these poles without the use of mechanical crane. By jacking it up on a simple scaffold frame and lots of hauling on ropes, we levered our ridge poles into place. Everyone including our office staff were eager to lend a hand. Muscles bulged, eyeballs popped and that was just the bystanders.
With the ridge on, we can see a quite distinct curve along the roof line. In our case, this feature was the inevitable product of using an A-frame design to construct a building which narrows significantly at one end. The pitch of the roof has to remain the same throughout in order to retain the necessary 45 degrees slope for our thatch. Any shallower and the thatch’s ability to shed water is compromised. The only way to avoid this is to curve the ridge so it comes down to meet the apex of each of the principal A-frames as they gradually reduce in size towards the narrow end.
After we had finished congratulating ourselves on how brilliant it all looked, it began to dawn on us that you can see this same technique applied in Viking longhouses in particular, ostensibly for structural strengthening purposes. Perhaps our Neolithic house is evidence that this concept may have been utilised much earlier than previously thought?
Reconstructed Viking house in Ale north of Göteborg in Sweden. Photograph: Sven Rosborn (source)
With the ridge in place, we can finally begin to lay on the rafters. And with rafters come the hazel batons which are tied on horizontally, providing the bed onto which our thatch will sit.
Although we have already tackled some simple carpentry in this project, we are still very reliant on cordage to provide the lashings holding rafters, purlins and batons securely in place. In the Neolithic landscape we’d have been able to source the necessary materials to make cordage by stripping the bark of the Lime tree (Tilia cordata). Soaking or ‘retting’ these stripped fibres in water over a period of weeks, dissolves the pectin and cellular tissues that surround the bast fibre bundles, leaving you with slightly smelly (!) but very useful, flexible fibres. For a range of practical reasons, we have opted mostly for sisal. It’s still a natural, plant fibre but critically it can be obtained in the large quantities required in the middle of winter.
By next week, we should have installed the porch feature, meaning the skeleton of the building will be complete. Then the monumental task of thatching will begin in earnest. This could last 6 weeks, depending on what the weather throws at us. I wonder if we will last that long?
