Self-build with style
Alan Beat on the use of wattle and daub in buildings
This month I’d like to take a closer look at wattle and daub as a practical method of self-build construction for outbuildings on a smallholding.Continuous panelling or fencing Wattle isn’t restricted to the construction of free standing panels such as sheep hurdles. It can equally be used to make continuous runs of fencing or walling built in situ, thereby gaining additional structural integrity and the capacity to follow uneven contours. It’s somewhat easier to build continuously, since no supporting mould board is necessary and often no special starting or finishing patterns of weaving are required either. Upright poles can be driven into the ground or fixed into the framework of a building, while rods are woven between them in a straightforward fashion. Twisting of weavers around zales may also be unnecessary or, at least, restricted to each end of a long run.DaubAn internal wattle partition may remain serviceable for many years when protected from the elements, but exposure to rain or damp will cause deterioration and failure within a few short years. However, Iron Age man soon discovered that the application of a simple earthen plaster not only provided draught proofing and additional strength to the wattle, but also a sufficient level of weatherproofing to considerably extend the serviceable life in external situations. For these very practical reasons, wattle and daub became synonymous in building applications, and the combination remains in widespread use today by rural dwelling peoples throughout the less-developed parts of the world.Depending on what is available locally, daub is made up from a mixture of clayish subsoil, sand, fibrous material, animal dung (optional) and water, all worked into a pliable mixture that will stick to wattle before drying to a hard plaster. There’s no precise recipe but I’ve successfully used the following proportions, measured roughly by the shovel or bucket:• 4 parts clay subsoil • 1 part sand• 1 part manure• 1 part chopped straw• water to suitTo mix the daub, pile dry subsoil and sand together on a board or other smooth surface and mix with a shovel. Add manure and chopped straw and mix again. Now add water, a little at a time, and keep mixing. As the pile begins to hold together, tread it well and mix with the shovel alternately until the ingredients merge into one pliable even mass. If too wet, there’s a tendency to shrink and crack more on drying. Too dry, it’s more difficult to work into the wattle weave. Making up the daub is hard work and no, you can’t use a cement mixer, it just doesn’t work! You can, though, use livestock penned tightly to mix it with their trampling. Cattle were traditionally used for this purpose, and it’s been suggested that the inclusion of animal dung into the mix may originate from this practice. For more information on daub and cob mixes, read Cob Buildings – A Practical Guide referenced at the end of this article. Applications in smallholdingModern manufactured building panels of sheet materials are expensive to buy, come in standard sizes that may not suit, generally require the use of power tools to cut and shape, and raise issues of sustainability in manufacture and eventual disposal. But to the smallholder with access to the harvest from hedgerow or coppice, wattle and daub is free, adaptable, easily worked using only hand tools, sustainable, and recyclable. It therefore merits serious consideration as a practical method of self-build construction for the outbuildings that every smallholding inevitably needs. Barns for storage of hay and fodder, implement sheds for machinery, shelters for livestock, composting toilets – all these and more can be designed and built at minimal cost from materials gathered for free around the smallholding. Let’s take a closer look at two practical examples in which I’ve recently played a role. Celtic roundhouse The Celtic roundhouse developed from an original idea to make a children’s play house at the 2004 summer camp of the Yarner Trust in Welcombe, North Devon. The annual summer camp is an environmental arts holiday with an organised programme of hands-on activities. I volunteered to lead the construction of a simple playhouse based around a 6’ square of wattle hurdles, but somehow, this grew into the more ambitious project of a sizeable Celtic roundhouse, with wattle and daub walls and a thatched roof – don’t ask me how, although Rosie’s enthusiasm at planning meetings undoubtedly had something to do with it! Five morning work sessions of two hours each were planned for the project, and at the appropriate stages I would be assisted by two other leaders with carpentry and thatching skills.After some research and discussion, it was decided that a roundhouse of 12’ in diameter was ambitious but achievable if sufficient numbers of volunteers were attracted to participate. At this size, the roundhouse would be large enough to provide a useful covered space for future events, courses and group work, or family accommodation. I was planning to re-lay the roadside hedge of our smallholding during the coming winter, and a careful inspection of this hedge convinced me that sufficient rods and poles could be harvested from it to weave the roundhouse walls and construct the framework of the roof.I had no suitably rot-resistant poles to set into the ground for the load bearing framework of the wall, however, so larch poles of 4 to 5” diameter were ordered for this purpose from a local forester. A locally available material such as soft rush or barley straw could have been used for thatching but, by this point, a grant had been obtained for the project that covered the purchase of water reed instead, the best quality material offering a potential lifespan for the roof of 30 years.As August approached, I began cutting wood from the hedgerow. Of course, summer isn’t the ideal time to do this, but the birds had finished nesting and it does no harm to the trees. I worked in the cool of the evenings, selecting and cutting out suitable rods of hazel and willow for weaving, plus ash and elm in poles of larger diameter for the roof structure. Twiggy side growth was trimmed off and the wood tied into bundles for storage in the shade of the hedge bottom until needed. A few days before summer camp, I loaded up my estate car and roof rack with these bundles and transported them to the site.When siting an open-fronted implement shed or livestock shelter, much the same considerations would apply today as for a roundhouse dwelling in the Iron Age. Within the three acre field available, I avoided the wetter and steeper areas and chose a corner that was almost level, and appeared firm and well drained. The doorway would face south, away from the prevailing westerlies and maximising the sunlight entering the building, whilst nearby hedges provided shelter against winds from the north and east. A circle of 12’ diameter was marked out using a string swivelling on a peg driven in at the centre, and 18 equal spacings for the upright support posts were measured around the circumference and marked by pegs. Then I dug the first post hole to check the ground conditions. There was a 6” layer of dark topsoil with lighter clay subsoil beneath, while 18” down I found a layer of broken stone set amongst hard packed clay, which was ideal for a firm, load bearing foundation. At the first session of summer camp I was pleasantly surprised to find that around 20 people had volunteered to spend most mornings of their annual holiday working on the roundhouse project! They eagerly began setting the circle of upright support posts some 18” into the ground, using an assortment of shovels, spades, picks and bars, while I attempted to co-ordinate operations. Within two hours this first stage had been achieved.On the next morning, I demonstrated how to weave rods between the upright posts and set the volunteers back to work. The wattle walls grew rapidly as enthusiastic hands wove back and forth around the circle, while I attempted to oversee that the weave stayed reasonably tight and even, to the finished height of four feet. No twisting of rods was necessary at the two end posts of the weave, which, for this circular wall, were the door posts, so it was relatively easy work for novices, and again the task was finished within the session.The third session tackled the construction of a ring beam around the top of the wattle wall to provide a sound bearing for the roof structure. This ring beam was to be built up from 18 individual straight poles, lap-jointed and firmly pegged to each other and to each upright post. The weight of the pitched roof would apply an outward spreading force to the top of the wall, as well as vertically downward, and the inherent strength of a circular beam would resist these forces. The carpentry skills of marking, sawing, chiselling, drilling and pegging were guided by another leader, using modern hand tools very similar to those developed by our Celtic ancestors. The volunteers found this more challenging and the task ran over into the following morning, taking around three hours to complete.Running behind schedule now, we started work on the roof structure. Three long, straight poles were used as main rafters that were loosely tied together at the top whilst lying on the ground, and then raised to form a tripod with the legs equally spaced. A pre-cut notch near the base located each rafter onto the ring beam, to which it was drilled, pegged and lashed with sisal cord (old-style baler twine). The roof pitch was set at around 60° for the thatch to shed rainwater effectively. Further rafters were lifted into place one at a time, secured to the ring beam in the same way, and eventually all lashed together at the apex. A second ring beam of thick yet flexible rods was lashed into place at two thirds of the rafter height for additional strength; while to avoid overcrowding of rafters at the apex, some intermediate rafters were terminated at this ring beam. Finally, purlins were formed using concentric rings of flexible rods lashed into place at intervals, to support the covering of thatch.All this took us part-way into the fifth and final morning session, when thatching the roof could begin under another leader. Water reed was tied into bundles and lashed in a concentric ring around the lower ends of the rafters. This supported the first round of thatch, which was lashed to the purlins above and spiked into the supporting reed bundles with spars made from split and twisted hazel. Each successive layer of thatch then overlapped the one beneath, and was tied and spiked firmly into place in the same way. The butt ends were batted into position for a smooth finish as work progressed. Some volunteers were so fascinated by this stage that they returned in the heat of the afternoon to continue thatching, but even so, the roof was nowhere near finished by the end of the day, and the leader returned in his own time to complete it.Daubing of the wattle walls was carried out by students on a training course under another leader, but around one quarter of the wall remained undaubed and I subsequently led a small group of volunteers to complete this section in a session that lasted two hours. Ideally, we should also apply a smooth top coat and then several coats of lime wash to protect the daub.At a rough estimate, it had taken around 250 person hours of work to build, thatch and daub the roundhouse, while everyone concerned had thoroughly enjoyed the experience. The end result is a substantial and attractive building that now plays a significant role in the Yarner Trust’s outreach programme of educational visits and activities.Green oak framed barnIn 2004, the framework of a small green oak barn was erected by students on a training course at the Yarner Trust. The roof was clad with chestnut shingles, and it was planned to fill in the wall framework with wattle and daub panels. This is where I first became involved, helping the tutor of a weekend training course to guide students in wattle panel construction.Two problems immediately presented themselves. The first was that most panels followed the irregular contours of curved oak crucks, and so couldn’t be woven in the same way as conventional square or rectangular panels. The second was that some triangular panels were of very small size and tapered away to a point! I hadn’t tackled anything like this before, so it was quite a challenge.We began by fixing zales or uprights of split ash into sockets chiselled into the oak frame, cutting the zales carefully to length, then bowing and springing them into place. Against the curved faces of the crucks we nailed lengths of split ash to act as end zales. We split hazel rods into halves and began weaving. By cutting the weaver carefully to length first, it could be threaded through from one end, passing in front and behind alternate uprights until it nestled snugly against the far end zale. This was more difficult and time consuming than weaving from above in the conventional way, but it worked.The triangular sections posed the additional challenge of securing weavers as the panel narrowed towards the point. Weavers could be sprung into place between three zales, but obviously not between only two, so in these areas we drilled and nailed each end of the weaver to the zales. Again, this was slow but it did the job.There were lessons to be learned here, for it would have been so much easier and faster to fill in square or rectangular openings with wattle, and this could have been designed into the framework of the building.The students were unable to finish all the panelling and it took a few more sessions of voluntary work by myself, the tutor and others to complete the task. More volunteers carried out the daubing over several sessions. A base coat was pressed firmly into the wattle from both sides, then a top coat was smoothed on and finally painted with lime wash, allowing plenty of time for drying out between stages.The barn is now fitted out as a compost toilet block to provide facilities where no mains drainage is available. I’m unable to estimate the overall person hours for this building as I wasn’t fully involved throughout, but I can say that the final result looks impressive and should last for very many years to come.SummaryBoth these self-build examples could readily be applied to practical use on the smallholding. A roundhouse or timber-framed barn could provide storage space for fodder, machinery or implements, serve as a workshop space, or as a shelter for livestock. Their size is limited only by the available materials, and although oak is ideal for longevity, especially when set into the ground, any reasonably durable timber can be used in its place. Old but sound telegraph poles or railway sleepers can be a relatively cheap source of suitable timber beyond the smallholding.Keep in mind that most of the labour in the examples above was relatively unskilled. The basic skills to sketch out and construct your own building are straightforward to master and should be well within the capabilities of most practical smallholders. If you lack confidence in your abilities, training courses are available to provide hands-on experience that will set you off on the right path.There seems no good reason why the self-sufficient smallholder shouldn’t design and build his outbuildings with his own hands, almost entirely from the resources of his own smallholding and at minimal financial outlay. If the Iron Age Celts could do it, then we can do it too – it’s just that we’ve almost forgotten how.
This article is from the June 2006 issue of Country Smallholding magazine. << To order back issues click the link to the left.