Burnt daub and the ghost of wattle

Lately I've been washing a lot of ruined building materials, debris from a house fire 2000 years ago.

Me, my friend Howard and his students excavated a Viking Period boat burial in Östergötland last summer. It dated from the 9th century AD and was sitting on the remains of a settlement from the 1st century BC. We weren't there to study that period, but we ended up with a shitload of burnt daub. Thousands of pieces of fired clay with imprints of twigs and straw.

Wattle and daub is a cheap and sturdy technique for building house walls. The roof of your 1st century BC house has its own supporting posts. Between the eaves and the ground, you fix slim stakes where you want the wall, and then you weave thin withes between the stakes making a basketwork screen: wattle. You then mix clay with straw and dung and daub the wattle from both sides. Stays wind-proof for decades. Then, when your house burns down, as it is likely to do when you have no chimney and warlike neighbours, the daub turns into coarse ceramic chunks. Which archaeologists will collect, wash, dry, weigh and photograph.

This is boring and pointless. We collect the stuff because it's clearly artificial and has a funny shape. It occurs in humongous quantities, 100s of kilograms from one site in some cases. But we have yet to see any interesting information about life in the past come out of burnt daub. At excavations, we look at it and say, "There's been a wattle-and-daub structure here, and it's burnt down". And this is as far as burnt daub takes us.

There's an on-going discussion about this issue in contract archaeology. A few years from now the standard procedure will probably be to document where the daub was and how much it weighed, then collect, say, ten of the largest and most intricate pieces from each context, and dump the rest. But I didn't feel I had enough clout to try to set a precedent with last summer's dig. So I'm doing the washing up.

Addendum 4 January: a shitload is here defined as roughly 18.1 kilogrammes.

[More blog entries about Iron Age, archaeology, Sweden.]