Name that wall

[Jellyfire]

Hi, bit of expert identification needed if possible please. All our internal and external walls have been loving covered in gypsum plaster and cement render. This is cracking and falling off in places, so Ive finally bitten the bullet and decided to deal with it head on.

Ive removed the plaster from one wall, and much to my surprise it came off like a dream, in large sheets, and was barely bonded to the wall behind. Now I was expecting to find lath/metal mesh behind it, as this is visible in a couple of exploration holes I'd made previously. Instead the infill panels are what I assume to be clay lump or wattle and daub.

The panels seem to be rock hard, and the other side of the wall is plaster-boarded over and inaccessible at the moment as its in the kitchen which Im forbidden from messing around with until Ive actually finished one room at least! The infill panels seem to be pretty thick from where I can see into a gap next to one of the timbers, I'd say approx 6 inches of solid material, then I can just make out the what may be lath or wattle.

There seems to be the residue of a little lime plaster in places, but not very much at all, and the surface is in excellent condition, so Im wondering if it would have ever been plastered over or maybe just limewashed? Now Ive uncovered it it would seem a shame to cover it in plaster as its an attractive surface, so would it be advisable to limewash directly onto it or should I be giving it a skim of lime plaster to protect it?

On a slightly separate note, would I be foolish to attempt to lime plaster (this and also some lathe walls of which the majority will probably be) myself with no experience, or is it very much a job for the professional. It's a 16th Century suffolk cottage, so I wouldn't be wanting a pristine flat finish, but I would like it to be solid enough to stay intact and not look like the daubings of a madman!

Pictures attached, any advice appreciated!

 

[Keithj]

The wall without the covering looks exactly like our internal walls, in a Suffolk Tudor cottage. Can you identify what the fill between the timbers is? To me, it looks a bit like the scratch coat of our lime render, but with the scratching mostly gone.

Do you want to cover it up, or would painting it (possibly limewashing) suit?

Here's our interior - the timbers are black because that's how they were when we bought the place, walls painted pale beige (I think it's called magnolia):

 

[Jellyfire]

To me, it looks a bit like the scratch coat of our lime render, but with the scratching mostly gone.

Hi Keith, I don't think it shows very clearly on my pictures, but it has quite a lot of straw in it and the panels seem to be about 6" thick, so Im not sure that would tally with it being a scratch coat of lime render would it?

Do you want to cover it up, or would painting it (possibly limewashing) suit?

Ideally I'd like to leave it exposed, but patch up the holes (daub, lime?) and then limewash it, but not if it will cause it to start deteriorating

Here's our interior - the timbers are black because that's how they were when we bought the place, walls painted pale beige (I think it's called magnolia):

So was that wall a year and a half ago, it's taken me that long to strip the beams, which is why Im not allowed to start knocking holes in the kitchen wall yet!

 

[Keithj]

6 inches and straw doesn't sound like lime render, certainly. Mine's more like an inch thick on laths, and laced with hair, although by now the hair has probably vanished.

There'll be an expert along soon, who will probably identify the precise material and where it came from.
I would be surprised if you couldn't put a coat of lime over it and limewash it (but not in winter).

If you are in Suffolk and want a recommendation for an expert, I know one (she did the brainwork for the repairs to our house - see http://jillings.org/tudor ).

 

[FamilyWiggs]

Is the house listed? If so, a chat with the Conservation Officer would be in order first.

 

[middi]

It's DAUB. It's highly complex material constituents are made up from ( wait for it !!!!!) subsoil, chopped straw, animals dung, water and a good helping of urine.
This would have been mixed by any means available into a tacky " slurp" and HAND applied to the wattles in one application.
A finising finer coat would have been applied if desired , especially useful if the surface needed to be decorated.

The most practiced method of infill beteween studs in walls, gradually loosing favour to plaster and laths towards the end of the 18th C.

Wattle and daub must have a good breatheable covering if it is inteneded to be decorated internally ( ie- lime skim).
Whilst it was originally just limewashed externally, this required regular maintenance to keep it in good order. Usually the lower panels above an horizontal beam ( accumulation of water ) eventually will disintegrate first. Due to this, owners just replaced the w/daub infills with either bricks, boarded the exterior with lap boards or lath and plaster. A natural progression into other building practices.
Cement render on the exterior of these panels is a definite NO. To protect and conserve these panels the best practice is to cover them up externaly with provision of adequate air flow.

Middi

 

[Jellyfire]

Thanks all. FW yes the house is listed, I have got LBC for other changes we have planned, but as the intention with this was just to replace the plaster which is falling off then as I understand it thats just a repair so doesn't need permission?

Middi, thanks that is very helpful to know. So would you recommend a skim of lime plaster on this. It's formerly an external wall is now an internal one as the house is extended. We have concrete render on the exterior walls, I think these are possibly mainly lath, but I imagine at least some of it is going to be W&D too then. We have a very large overhang on the thatch and the walls barely even get touched by rain so I'm hopeful they wont be very damp, there doesn't seem to be any external signs of it in the plinth etc.

When you say best practice would be to cover them and maintain airflow, what would be the method for that, how would that be achieved?

Many thanks
Jelly

 

[middi]

It is good to know that you have a generous thatch overhang, W&D benfits from this.

As to the internal walls surfaces, a single coat of lime plaster could be applied for you to decorate on ( preferably with limewash), the surface of the daub should be already suitably " rough" to form a " key" for the plaster to adhere to it. If powder dry this should be dampened before the plaster is applied. On no account attempt to use a sticking agent ( ie- unibond etc.) thinking that you will get a better grip. Most of these sticking solvents are waterproof therefore defeating the object.
( originally w&d was finished with smooth clay)
As to the external walls, there are a number of options you can pursue. First of all the cement render has got to be removed. For simplicity you could install a breatheable membrane stretched tight across the exterior of the studwork, then a S/steel lath mesh on top of which your lime plaster finish. another easy option ( and an excellent one) is a breath. membrane as above but instead of lime plaster you could use lap boards , this option will guarantee perfect airflow for the wattle and daub.
Whilst w&d is an excellent insulator, you could exploit the possibility of further insulation " blankets" across the exterior of the studwork, counterbattened and with a lime render or boards above this . If this optioned is pursued you may have to overcome difficulties of the slightly increase in walls thickness externally ( normally not a big problem).
These are some option as to how it could be done. You may need to keep the CO informed, an uninfirmal chat beforehand may be a good thing.

Middi

 

[Zebra]

would I be foolish to attempt to lime plaster (this and also some lathe walls of which the majority will probably be) myself with no experience, or is it very much a job for the professional. It's a 16th Century suffolk cottage, so I wouldn't be wanting a pristine flat finish, but I would like it to be solid enough to stay intact and not look like the daubings of a madman!

I went on a lime plastering course at Ty Mawr in Wales. It was excellent. I learned so much. It was about half and half split between professional plasterers wanting to learn lime, and people like you and me wanting to work on our own houses. There was theory and practical sessions (my fist go ended up on the floor). Nonetheless I shall have a go here.
You can buy the stuff ready mixed too so you don't have to worry about getting the mix wrong.

 

[Penners]

Jellyfire - you have an excellent identification of your wattle and daub from Middi above. I just thought you might be interested to see how this infill is achieved.

There are many ways of creating the wattle, but the most common is a series of split poles or staves - often chestnut - sprung into grooves in the timber frame. Into these is interwoven withies of hazel or willow. The resulting wattle or "hurdle" is then thickly daubed with ...daub (see Middi's family recipe above!).

Withies were mass-produced by pollarding trees, and were used for all kinds of purposes, including construction, fencing, roofing, etc.

You're very fortunate to have it in such good condition. It's a structural system that goes back to the iron age.

Here's a sketch that I've found - I hope it helps to explain the method.

And here are withies being harvested:

 

[middi]

Nice pictures Mr P.

Middi

 

[Jellyfire]

Thanks for the advice all, all of it very useful and taken on-board. I think for now the external walls will have to wait a while. I think my best option is to start by having a go at skimming the interior walls with lime plaster. Pretty much all the walls inside and out will need dealing with at some point and the thought of having to pay somebody to do it all doesn't bear thinking about, so in the long term its probably worth the effort of learning the rope and hopefully eventually I'll be able to tackle the exterior myself.

You can buy the stuff ready mixed too so you don't have to worry about getting the mix wrong.

I must admit this option appeals, does the pre-mixed stuff stay usable for a decent amount of time does anybody know, or would it really be just as easy to make my own mix up, which after reading the various problems people seem to have encountered makes me slightly nervous?

Although a course would be great Zebra, afraid time and money probably make this unfeasible, so was hoping a bit of reading, the Mike Wye DVD mentioned on another thread and some trial runs might be enough to get started!

 

[MdB]

I would suggest starting out with bought mortar but then swapping to making your own once you realise it costs a quarter of the price. I haven't tried adding hair which some say is not the easiest to do without clumping so you might want to find the best way of doing that.

Unhaired lime mortar (not NHL) will last forever in the tub. Haired lime will dissolve the hair over a period of a couple of months and is recommended to be used within a couple of weeks.

My lime use is pointing and building rather than plastering but if it is like gypsum, it is well worth having somebody to show you the ropes / answer your questions. I didn't find it too difficult to learn but I didn't get it right straight away.

oh and yes it can be fun getting the mix right if you make your own. For example, Cornish sand typically comes from the china clay works and has had all of the very find grains removed. This means you a 3:1 mix is useless and you have to have something closer to 2:1. hmm, thinking about it, it may be worth including some silver sand next time I mix a batch.

 

[JohnB]

We had a group session of plastering last weekend, with someone who knows what they're doing teaching us. We used Eco Right products supplied by Celtic Sustainables in Cardigan, so not very local to you! I bought lime putty, Course Stuff and Fine Stuff. The Stuff is ready mixed and was ready to use, so we started with that. It meant we got going without having to do any mixing, but it's more expensive. Then we used a 3:1 mix with sand from the local builders merchant and lime putty. The liquid was drained off the putty, and it was mixed with 2 parts sand, as it makes it easier, then the 3rd part was added. Goat hair was sprinkled in a few strands at a time. Chucking a load of hair in makes it end up in a clump!

A 25kg bag of Course Stuff is £7.80, compared to a 20kg tub of lime putty at £10.20, plus a few 15kg bags of sand at £2.40.

We were applying it by hand, to give the effect of years of limewashing, as I didn't want a boring flat surface!

 

[MdB]

The Stuff is ready mixed and was ready to use,

I would want to put it into a mixer to wake it up a bit before use. Lime likes being bashed around, it makes it a lot easier to use. For small batches I use a bucket and a paddle mixer in a SDS drill.

 

[JohnB]

The Stuff is ready mixed and was ready to use,

I would want to put it into a mixer to wake it up a bit before use. Lime likes being bashed around, it makes it a lot easier to use. For small batches I use a bucket and a paddle mixer in a SDS drill.

It was mixed up a bit in a bucket with a spade. I didn't do any of the mixing, so missed out some of the details!

 

[Me!]

Withies were mass-produced by pollarding trees,

Although, just for the sake of accuracy as I know how Penners likes to maintain standards on this forum, the withies are being produced by coppicing rather than pollarding in the foreground of his picture.

Blimey, I do hope I’ve got that right, … I must be mad thinking I can correct Penners on his use of English!

 

[JohnB]

Although, just for the sake of accuracy as I know how Penners likes to maintain standards on this forum, the withies are being produced by coppicing rather than pollarding in the foreground of his picture.

Blimey, I do hope I’ve got that right, … I must be mad thinking I can correct Penners on his use of English!

The ones in the background are pollarded! Coppicing is an activity for people with good backs, and pollarding better for those with bad ones .

 

[Penners]

Me! and JohnB are both absolutely correct, and they jointly win my little contest to see who would spot this.

Ahem...!

 

[robgil]

I used a chalk and putty mix to skim over daub panels in the past, I soon realised that limewashing the daub has a similar effect!
Usually people who plaster over daub do so because their daub is in a poor state, yours seems to be OK.
Interestingly there are two trains of thought regarding the inclusion of urine and dung in daub, some say it is an added binder however some also say it is a by-product of mixing the daub under cows hoof. Daub would not have been mixed by hand, cattle would have been used if a lot of daub was required.
Dung was too valuable a material to be wasted in daub.

The chalk mix can be bought from Anglia lime just outside Sudbury or mixed your self, and it can be sanded smooth when dry.