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Wattle and Daub - Understanding Organic Buildings

Wattle is the term used for fixing twigs or sticks (usually cleft or riven hazel, oak, ash) between studs on a timber frame building to form a Wattle & Daub cottageskeleton onto which the daub will cling, one method is to spring ledgers between the studs to form a ladder effect. Original ledger positioning can be seen on old studs by means of a long groove on one side and a short groove on the other ,thus allowing the ledgers to be wedged securely in place top and bottom. Hazel stalks, which were usually cleft, are then tied to the ledgers leaving carefully spaced gaps to allow the daub to wrap itself around. There are several different methods of wattling, and the style used will be determined as to what area the frame is in, and the wood used in the main construction.
Daub is then applied to the skeleton framework between the studs by means of throwing and working the material around the hazel insuring the daub pushes through the other side, carefully building the material to the required thickness, working both sides of the frame together. As this is a vernacular from of building many variations can be expected in mix proportions and methods used. When attempting repair, remember the importance of inspection, record everything you see by making some notes and sketches, these will ensure correct methods are used and everything goes back just as it should.

Benefits of organic materials

One of the most important benefits of using wattle and daub construction is its ability to be flexible. Timber frame buildings move for a number of reasons, therefore by using natural and organic materials this will ensure that the infill panels move with it, due to the wattle skeleton frame. This does not happen with quick -fix modern alternatives such as hard bricks and cements mixes. Sand cement renders form an impermeable skin which will not allow movement without cracking, water by means of rain, can then enter these cracks and cannot escape by means of natural venting and breathing, the water then becomes trapped inside the structure causing damp patches internally which can sometimes be seen, also rapid disintegration of the timber frame itself will take place which cannot be seen quite so easily, as it will rot from this inside out. In cold weather the water content can freeze and result in further cracking and acceleration of the problem. The photographs show how infilling using hard bricks layed with sand cement has reduced flexibility of this original internal wall. Just like many other timber framed buildings of this age, this wall was originally built straight from the ground with no damp proof course of natural slate, there fore the plinth wall would take up moisture from the ground and then vent it out through the natural organic materials.

Another Wattle & Daub cottage By studying the photographs you can see the damage that has been caused by further use of a sand cement render and how it has prevented the wall from breathing, trapping in moisture causing the main timber frame work to rot and crumble away. In effect it was only the sand cement render keeping the wall in-situ. Above the modern materials are the original materials, good old wattle and daub. Note how the timbers become solid again and the original hand cleft lathes are still in place with their hand made wrought iron nails, every conservation officer’s delight. The modern material needs to be carefully removed whilst ensuring the wattle and daub stays in place, the part original soft red brick plinth wall will be extended using the same bricks layed with a coarse lime mortar, onto which a new sole plate will be layed which will then enable us to splice new studs to old using the same timber and the correct joints. The same method of wattle and daub will be used in the re-construction of this old and interesting wall. Once the daub has reached a stage of dryness that will still provide a good green suction, it will be keyed with a stick pointed at one end in a diamond formation, not to deeply, about 5mm, ready to take the haired lime plaster coats. When attempting minor repairs yourself, remember, the daub has no nasty modern chemicals, therefore you need not worry about losing old daub, as you need only soak it in water to re-constitute it, it does have a nasty old ingredient which is vital, cow-dung and urine, so be sure to wash your hands before you eat lunch!

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