Marianne Suhr: Wattle and daub

Click on gallery images to view larger picture.

The project: A 16th-century timber-framed house with later alterations.
The challenge: To remove a doorway and replace with a traditional wattle and daub panelled wall.

When we first moved to our dilapidated timber-framed house in Oxfordshire, I have to admit to being a little daunted. Having only ever worked on stone, brick or cob buildings, the prospect of renovating a house made of sticks, filled in with mud and twigs, was fairly terrifying. I knew the house had been rendered in cement 40 or so years ago, and therefore the timber frame and the infill panels underneath were likely to be badly decayed. Our first job was to gently lever off the cement skin and reveal the historic structure.

Patch repairs
As predicted, where the old wattle remained, it was in very poor condition, but I was able to patch repair most of it just using locally dug earth mixed with straw. But two panels were so badly decayed that they required complete replacement. I googled the words ‘wattle and daub’ in search of a local supplier of materials, but without much success. Then during a visit to our local pub, a chap at the bar suggested I contact Peter, the village expert on wattle and daub.

After explaining my plight, Peter appeared with a selection of oak staves and hazel withies – exactly what I needed to build the woven framework for my new wattle and daub panels. Peter explained how he had spent several years restoring and conserving his own timber-framed house, removing cement render from the panels and black paint from the ancient timber frame.

Over a period of time he had developed an effective technique for reinstating missing panels using only locally sourced, free materials. Peter discovered a particularly useful footpath while out walking his dog, lined with overgrown hedges of hazel – this is the perfect material for the withies that form the woven panel on to which the mud daub is applied.

Refining the approach
Peter finished repairing his house a few years ago, but he had always wanted to take out a later doorway and reinstate wattle and daub in the gap. When he told me his plans, I was really keen to watch him at work. He started by forming a blunt point on either end of an oak stave, poking one end into a hole at the top and pushing the bottom end along a groove until he achieved a tight fit. He then started weaving the hazel rods (withies) in between the staves to form the wattlework panel.

‘It took me a while to perfect my technique,’ he explained. ‘One of the things that puzzled me at first was just how to get the last of the withies in between the staves when there’s no room left for manoeuvre.’ Apparently, the key is to keep back the bendiest and most pliable hazel rods for use right at the end.

Peter’s approach was the ultimate in ‘vernacular’ architecture; using only home-grown techniques and materials, he had turned a once damp and decayed house into a beautiful place to live.

Checklist: Repairing infill panels to a timber-framed house

• Cement render over infill panels externally is likely to trap water and accelerate decay to the frame – ideally it should be removed and replaced with lime render.
• Most wattle and daub panels have been replaced with later brickwork. If you do discover wattle and daub, it is likely to be very old and worthy of careful conservation.
• If the wattlework panel is intact but the daub is damaged, mix some locally sourced subsoil with a little straw and water. A local building site is usually a good place to find your subsoil.
• If the wattles and staves are badly decayed, then it may be necessary to replace them. Ideally cut your own from a local hedgerow, or buy them from a local supplier.
• Always save the crumbly old daub mix, crush it up, add a little water and reuse it.
• Although commonplace, the use of mastic to fill gaps around an infill panel can trap water – better to chisel out the mortar around the edge and replace with a breathable lime mortar.
• If you are carrying out repairs to the timber frame which necessitates removal of the infill panel, consider replacing the panel with Hemcrete – a mix of lime and hemp – which can be shaped to appear as wattle and daub while providing far better insulation.

Reno expertise: Improving energy efficiency
Timber-framed buildings with infill panels and exposed frames are among the most energy-inefficient buildings. This is because of their thin walls and leaky air gaps around the edges of the infill panels. It is important to find out how your building performs before embarking on any repairs. This can be done by commissioning the following:

• Air tightness test A fan is placed in the frame of your front door to depressurise the building. Within minutes, the low internal air pressure causes air from outside to be sucked into the building, making draughts or air leakage apparent. The test takes one to two hours and costs around £250. Try Airtightness Testing (UK), (01621 893226; airtightnesstesting.co.uk
• Thermal imaging test A photograph is taken with an infra red camera on a cold day. Areas of heat loss in poorly insulated parts of the building show as yellow and orange. This costs around £400. Some district councils run a camera loan scheme; or try private companies like Thermascan (01234 219421; thermascan.co.uk), or Richard Bartlett at One Stop Automation (01993 878054; osaltd.co.uk).

WORDS & PHOTOGRAPHS MARIANNE SUHR
Featured in the May 2010 issue of Period Living