The Bronze Age Build Blog - Session 12
Project Coordinator Sue Webber gives the latest update on the Bronze Age roundhouse project as the volunteers get stuck in to the very satisfying job of daubing!
Daub therapy
While the thatching progresses, we also continue to work on the walls beneath. Daub is the material that goes on to wattle to make wind-proof roundhouse walls. It’s the school children’s favourite recipe of mud, water, straw and animal poo! Once mixed together it makes a sticky substance that can be smeared over wattled walls and into twiggy cracks and cavities.
Daub needs protection from the rain if it is to dry, so we needed to wait for the thatching to start before we could daub the walls under the thatch. We’re not daubing all the walls in this house because we are testing a variety of wall types and materials.
Our daubers soon discovered the delights of smearing daub on wattle walls. They enjoyed the work so much that it became a slow, social process that we named “daub therapy”. You can sit and talk while you daub and you gradually watch while your work covers the wall, giving a sense of achievement and satisfaction. It’s hands-on work at a human pace that probably felt the same 3000 years ago when the Bronze Age builders were working.
Our experimental walling choices have already started to give us results about what works, and what doesn’t. We built some lightweight wattle walls and banked turf against one and loose soil against another two. The turf wall is consolidating well with a good variety of plants growing there already. The smaller soil-banked wall is doing fine but its wider brother started to bow inwards from the pressure of the soil banked up against it.
We can see that this would soon be a problem with the weight of the soil forcing the wattle inwards, so we decided to remove the soil, release the pressure and see what we could do to re-consolidate the wattle. Once the pressure was off the wattle, we were able to straighten it up and support it with some extra uprights that slotted into holes in the lintel above the wall and into holes in the ground that we then packed with flint chips and earth. This has made a great improvement and the wall will now support the weight of the soil banked up against it once more. Just to be safe we have also added two more large uprights at either end of the wattle wall to lock it in place. While we have now strayed a little from the archaeology on this wall section, we have learnt some valuable lessons.
Lightweight wattle walls won’t support a soil bank if they are wide and if they are not firmly anchored. Because we followed the original excavation on the positions of the post holes we couldn’t make the distance between the posts narrower. So, this means that either this wasn’t a banked soil against wattle wall, or if it was, the wattle would need to be securely anchored to support the weight of the soil.
As our work continues, we’ll get more information on which of our experimental wall-types work and which aren’t so successful. It’s only by building these different walls that we can get a real understanding of the options available to Bronze Age builders.