Have you fallen in love with a historic property? Are you curious about how period homes always seem so quirky and unusual? The secret is usually woven into the building itself, thanks to construction techniques that have become unconventional to use today. While strange-looking façades help old buildings stand out from the crowd, they often come with a plethora of very specific problems.
Wattle and Daub
Wattle and daub is one of the most traditional property constructions found around the UK. It’s made up of thin wooden strips that are woven into panels (the wattle) and are then coated with a mixture of soil, clay, sand, straw and animal dung (daub). The low-cost, sustainable nature of wattle and daub has meant that, despite being used for at least 6,000 years, it’s seeing a resurgence in popularity as a construction material.
Why can wattle and daub be troublesome? Well, as historic building materials go, it’s actually fairly resilient. The slightly flexible nature means that walls can tolerate considerable structural movement and its sturdiness will even support a failing timber structure where other types of infill would not.
However, since it became fashionable to leave both the internal and external sides of these timber frames exposed, the performance of wattle and daub walls has been compromised, letting in draughts and occasionally water. This can cause a wider problem with damp, if left untreated. Ideally, the exposed side of the wall should be coated each year with limewash (killing off bacteria and filling in any small cracks), while the other side should be covered in render or weatherboard.
The worst thing you can do with a wattle and daub construction – or any timber-framed building – is to cover the historic fabrics with a modern, impermeable material. These prevent the buildings from “breathing”, causing a build-up of moisture and decay.
Bungaroosh (spelled in various ways, including ‘bungarouche’ and ‘bunglarooge’) is a composite material comprising of building site scraps that would be mixed into hydraulic lime. Broken bricks, flint, pebbles, bits of wood and other miscellaneous pieces would be mixed in with a mortar and poured between shuttering to set.
Bungaroosh was used almost exclusively in Brighton and Hove, East Sussex, in the 18th and 19th centuries, although some buildings in the nearby towns and villages have bungaroosh features too. If you visit Brighton today, you can see still countless Regency townhouses with an immaculate cream render, many of which are hiding bungaroosh beneath the surface.
Although it was a cost-effective way of using up materials, Bungaroosh is not the most reliable building fabric. The mis-mash of textures means that Bungaroosh is generally very porous. This means that it can become brittle when exposed, either becoming too dry crumbling with little resistance, or getting wet and causing solid materials to become loose. Drilling into Bungaroosh is very difficult and can cause serious structural damage. Although many buildings used to feature designated wooden fixing points within bungaroosh walls, these are typically either covered up or in undesirable positions today.
Similar to bungaroosh, mundic (also described as mundic block), is a type of concrete that utilises local waste as an aggregate. In this case, rather than debris from the surrounding building site, mundic is mixed with the leftover materials from nearby mines. Popular between 1900-1950, you will almost exclusively find mundic in Cornwall, although there are areas in West Devon with properties that have been built using mundic materials too.
The major problem with mundic is that it’s hard to work out exactly what has been mixed into the wall, and in what quantities. If the aggregate has a high ratio of certain minerals or chemicals from the mine, this can actually degrade the concrete over time and cause serious structural issues. As any surveyor in Devon or Cornwall will explain, this has a huge effect on local property values. All buildings that are suspected to contain mundic will need to be tested, and if the percentage of mundic material is too high, mortgage lenders may refuse to support the purchase.
Sometimes it’s just interesting to know about these unusual construction methods from the past. However, if you’re planning to buy a historic home that might be built using wattle and daub, bungaroosh or mundic, exercise caution. These quirky materials can certainly lend charm and character to your home, just make sure a local surveyor inspects their condition before you commit to a purchase – you could end up with a very expensive pile of rubble!