The Roundhouse: Managing the Compost Heap

When the first thatch layer on our reconstructed Iron Age roundhouse in Shropshire was finished, we stood with John Letts, the expert on medieval thatching techniques who had taught us how to thatch, and he told us that a thatched roof has been described as “a managed compost heap.” Over the years, the truth of this has become clear. Our roundhouse is built in a wood, meaning that the roof doesn’t get as much sunlight as it should to dry the thatch after rain, therefore it rots more quickly than it otherwise would. Because of this, we have to renew the thatch more often than we would like. We completed the roundhouse in the spring of 2009. Eight and a half years later, we have just completed our third thatch layer.

Rather than stripping off existing thatch and staring again, renewing a thatched roof usually entails putting a fresh layer of thatch on top of what’s already there. Our latest layer is a spar coat, meaning that the thatch is fixed with long hazel ‘sways’ held in place by twisted hazel ‘spars’ pushed and hammered into the existing thatch.

The roundhouse is thatched with long straw as being more period authentic than the now far more common ‘combed wheat reed.’ Long straw thatching requires considerable preparation. The straw must first be layered into ‘beds,’ each layer being thoroughly wetted. The beds are then ‘drawn’ or ‘pulled.’ You grab a few ends of straw from somewhere near the bottom of the bed and tug firmly. As the straw slips out of the bed, it is straightened out and most of the leafy bits that will prevent rain from running smoothly down the thatch are left behind in the bed. More handfuls of straw are then pulled with the left hand and transferred to the right. When the bundle in the right hand is thick enough, you grab it firmly at one end and give it a shake. Then you run your fingers through it like a comb, stripping out more of the leafy bits. Then turn it over 180 degrees and do the same again, shake and comb. The cleaned straw is then laid across a length of string on the ground. Then you pull some more.

When your bundle of straw on the ground has reached a size where you can just about get two hands around the end of it, you tie the string around it. This bundle is called a ‘yealm.’ This preparation is hard, time-consuming work, and we were very glad to have such a great group of people arrive to lend a hand.

At John’s advice, the lower three layers of thatch were stitched in with tarred twine, tarred so that, in theory, mice won’t chew through it. In practice, they must have a hardier breed of mice in Shropshire, and we’ve had to replace some of the stitches with spars. Ah well…

Ideally, you need a ladder with nice, wide rungs for thatching. This is because the ladder lies flat against the roof and you need a wide rung to give your toes something to stand on. One of our ladders had rungs only half an inch across. Ah well, all along the line, since 2006, when we planted the seed for the straw with which to do our first thatch, we’ve had to make do with whatever tools we can find or make, and whatever time we can spare from other work. Under the circumstances, we’ve done pretty well.

The other-than-human inhabitants of the grove in which we built the roundhouse have been open to us from the start, when I found a deer skull on the first day we started clearing the ground.

We had wrens nest inside during the build, and there are still wrens who nest under the eaves. Buzzards have circled overhead, deer visited at twilight and, during this last thatch session, we were entertained one day by a group of wood mice who were remarkable friendly, strolling around our feet while we ate lunch and posing for Elaine’s camera.

We completed all the thatch we could on Sunday morning. We had used almost all the last batch of straw Elaine had bought in. We didn’t go right to the top of the cone, because, in the spring, we’re going to remove this part of the thatch, exposing the roof timbers again. Then we’re going to erect a new timber structure consisting of a downward-bending roof pole at either end of which will be a triangular opening to let out the smoke from the central fire.

Roundhouse reconstructions have, until now, followed Peter Reynolds, who built the first such reconstructions at the Butser Hill Farm in Sussex. Reynolds copied African roundhouses, but decided not to include a smoke hole in the belief that the smoke would permeate out through the roof. If the thatch is thin enough, a lot of it does, but a lot more doesn’t. It then depends how big your roundhouse is and how high its roof as to whether the resulting smoke layer is above or below head height. Our roundhouse is only 22 feet internal diameter, and that’s not quite big enough, so the smoke layer comes down to chest height, which means that unless you build the fire with very dry wood and keep it burning strongly, you’re breathing smoke whenever you stand up. Having had pleurisy a few years ago, I’m reluctant to expose my lungs to too much more smoke.

Fortunately, I don’t have to. It turns out that roundhouses had not one, but two smoke holes. Our evidence for this comes from little clay or metal models of roundhouses dating from the late Bronze age and early Iron Age and known as Villanovan hut urns. They seem to have been used as incense burners. Their roofs clearly show two triangular vents at either end of a downward-curving ridge pole. The same style of roof is being used in the Baltic region to this day. Given that it has been in use for 3,000 years or more, my assumption is that it works. In the spring, we’ll find out. Many thanks to Corwen Broch for drawing my attention to this hopefully elegant solution to our smoke problem in this excellent blog post.

A bonus in this year's thatching session was that Amanda, Ariana and Pete re-whitewashed the roundhouse and added spiral decorations on either side of the doors (see photo below).

Huge thanks to everyone who has worked on the roundhouse over the years. Between us, we have created an amazing, magical place, filled with ancestral voices, woven with music, poetry and ritual, a perfect venue for ceremony, journeying between worlds and communing with the spirits of the place and of the old gods of these lands.