Daubing on willow wattles?

[DaveBrigg]

Work in garden had to be put on hold last weekend because it was getting too muddy. Instead, I prised the cement panels off of the lime plaster on our staircase wall and found - mud. Mud and straw daubed on a panel of reeds, the reeds being held in place by a vertical lath on each stud.

As you can see, there is a big patch which need to be replastered, and some areas that first need repairing. However, the surviving reeds are extremely fragile and not likely to withstand a generous coating of muck. I can get replacements locally, but fitting them would involve cutting out a section of the original materials far bigger than the area damaged.
Another section of this wall has been repaired historically by having laths jammed in across the gap, which were then plastered over.
A local horse livery yard was happy to provide several bags of hair, and I have some willow staves which have been drying for six months, the perfect size to be split for laths. Is willow suitable for use this way, or will I have to source some ash?
I would also be interested to hear from anyone who has done something like this themselves. I've read the SPAB advice, but could do with some clearer guidance on what to include in the daub mix.

 

[biffvernon]

Sounds a fun job.

Willow is fine, but not after it has dried out as you won't be able to split it easily. Better to go and cut some fresh willow and if not using it immediately leave it in the long wet grass or in a pond.

This is a good time to gather reeds from the nearest ditch.

When mixing the mud try and aim for a range of grain sizes, sand, silt and clay. I use part subsoil and part sand from below the subsoil from my sandy land.

Hair in this sort of work is a bit of a luxury. I'd use chopped straw for the bulk of the mud and save the hair for the top coat.

 

[Gervase]

The exact constitution of the daub depends on your local soil - you want a clay soil rather than a sandy or loamy soil with a lot of organic matter, and you should also mix in a generous proportion of cow dung to stop shrinkage, help it harden and promote adhesion. Chopped straw was more commonly used than hair as a reinforcement - I'd be tempted to reserve the hair for any plaster that subsequently went on over the top of the daub, but see what's in the original daub and replicate that (shake up a small sample in a jar of water to see what sort of solids, fibre and the like were used).
Willow is fine as a substrate, and is more traditional than ash for wattle. However, although brittle, the reeds may still be serviceable if you do the daub in two coats; the first one a slurry to consolidate the reeds and the second a firmer coat applied once the slurry has had a chance to dry a bit
See this site for a comprehensive study of wattle and daub.

 

[andrew gayton]

hydrated lime will also reduce shrinkage.

hazel makes for a more durable wattle.

 

[Nemesis]

http://www.wealddown-schools.org.uk/Further%20information/information-wattle%20and%20daub.pdf

http://www.helm.org.uk/server/show/ConGuidance.195

A short book:

http://www.ricsbooks.com/productInfo.asp?product_id=11537


I know I have posted a link to a long scholarly study of wattle and daub here in the past - but can I now find it? Noooo.

 

[Nemesis]

Here it is:

http://www.tonygraham.co.uk/house_repair/wattle_daub/WD.html

 

[DaveBrigg]

Thanks for the excellent replies. I was afraid that someone would mention cow dung - there is a plentiful supply around here but I might leave collection to the children. Should make a change from the usual Christmas outings. The links brought up some detailed advice too; I'll post the 'after' pictures when it's done.

 

[Nemesis]

Ah yes - the dung. Sorry about that.

http://www.periodpropertyshop.co.uk/phpBB2/viewtopic.php?t=6397&highlight=wattle

PS Apologies to Gervase - those hidden links baffle me! Wondered where the site was...


PPS if you can conserve the reed it would be good...