| 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  skeleton
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.
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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