Wattle and daub
In timber-framed buildings, and in those of mainly timber construction such as Iron-Age round houses, windproof and well-insulated walls were constructed between the main timbers by a lattice of wattles, like basketwork, usually made from hazel rods. On to this framework was plastered daub, a mixture of mud with other materials, such as dung and straw. When this dried, a thin wall resulted that, as surviving examples many hundreds of years old show, could last well as long as it was kept dry.

Weeds of cultivation
With the introduction of agriculture and the growing of a relatively small number of crops over wider areas, other plants appeared that preferred the same open conditions but were not deliberately planted by people. Environmental archaeologists can identify these and, even in the absence of crop remains, can see them as evidence of agriculture. Such plants include cleavers, charlock, poppies, fat hen and corncockle.

Wood conservation
Before metal, and then plastic, became so abundant in recent times, wood was the most important material, not only for building work but also for implements, tools, containers and so on. But wood eventually rots away so any objects or structures made of it disappear and are not available for study by archaeologists. Therefore, when wooden structures or objects are found, usually in waterlogged, anaerobic conditions such as in fens, marshes or rivers, they can provide much more information than the range of inorganic objects found on most sites.

However, when they are removed from the place where they have been preserved in the right conditions, they will begin to rot if they are not conserved. There are a number of techniques now available to treat wood so that it can be preserved in a way that enables the objects or structures made of it to be examined and then put on display. The main one seeks to replace the water in the wood with soluble wax which will keep the shape, size and structure of the original material more or less intact.