anyone know anything about lime plaster

[TheStripper]

Evening all
Ooh, I'm v glad to have found this place. Wealth of knowledge for a total beginner/ idiot who is the lucky custodian of a very small, very old house (15th century timber framed loveliness).

To my question: I have been stripping beams. Joy without end (well, seemingly without end). Have used Klingslip, electric sander and an awful lot of elbow grease. I'm mostly quite pleased with myself apart from one beam: it's a vertical wall beam which whilst sanding I knocked some of the plaster off. Doh!

I have now inadvertantly exposed the ends of the horizontal lathes. Looks bad. What was covering ends looks like hairy lime plaster: can I match this with some kind of lime 'filler'? I really wouldn't need very much (not doing a whole wall: just about a dozen 'ends').

Can anyone recommend a product? And is this a specialist job or could a fairly competent lay person manage it? Any guidance very, very much welcome.

Thanks in advance,
The happy stripper

 

[JoceAndChris]

A big welcome to the forum. Just bumping this to the top as your post has only just appeared, it takes a few days for the first post to be approved.

I'm absolutely sure you could manage this bit of lime plaster filling. We have, also as complete novices. You'll need some specialist products, I'll pass over to others for more specific advice.

 

[JohnB]

You can get ready mixed lime plaster in plastic tubs or bags for around £10 for 20ish kilos. The stuff I bought is described as "Fine Stuff" or "Course Stuff" depending on how smooth a finish you can get.

 

[MatthewC]

Hi there and welcome

It's quite a straightforward job to apply lime mortar, but you never know until you try it. If this is a small job it sounds ideal for a go yourself, I think.

Method depends what thickness you have: on bare lath it's usual to add one layer of haired mortar, then another of plain mortar (both about half an inch) and then a skim of lime plaster (which is finer and gives a better finish), but it depends on what your wall is like! You'll need a metal plasterer's trowel, a gauging trowel to knock it up and a hawk, plus a wooden float if you're doing a big area. Also something to spray the wall with, something to scratch the surface of the scratch coat (use sharpened lath?) and a large sponge, as well as things to prevent/clear up the mess.

You can buy ready mixed lime mortar either with hair, or without and add it yourself, from manufacturers like Mike Wye, Ty Mawr or Old House to name but three (find them on Google). Compare prices including transport costs! If you're close-ish to Oxford/Buckingham I could let you have a tub of mortar and one of plaster for very little but you'd still need to buy some hair as I used all mine (I refer to horse hair, not the hair on my head, before any pedant here says anything! Being pedantic myself, it's "lath" not "lathe", BTW.)

Oh - almost forgot - photos please!

Matthew

 

[worms]

Oh - almost forgot - photos please!

Matthew

Lest there be any confusion, I think Matthew is asking for photos of the house, not "The Stripper"!

 

[FamilyWiggs]

If it is only a small patch, then to be honest, I've reached the point where I think it can be ok to repair with modern ready mixed stuff. Like Polyfilla.

Whilst this might seem heretical, and you might need to fiddle a bit to match th finish, I'm sure it's what our forbears might have done if it had existed. I will now be flayed by purists, but to be honest as a newbie I think you're more likely to be put off lime plaster if you have only a small patch to repair.

Of course if you have a larger section to do, lime is the way to go.

On a related matter, I would really really really, etc, recommend NOT sanding your beams :shock: , the character and centuries old patina is destroyed by such abrasive methods. Plus you run the risk of damaging the plaster! :wink:

 

[plasticpigeon]

I've been having a go with lime, and am in no way experienced I've just used it a couple of times. However I can say it's very hard to patch with lime as it has sand in it and tends to abrade the plaster that is being patched making a rough join between the two. Polyfiller usually needs to be sanded after which is ok if you're very careful but can also take the surface off the original plaster. I think it might be possible to use pure lime putty to fill the join, but again I'm not sure. Most lime suppliers are very helpful and enthusiastic so there is no harm phoning up to see if there is a suitable product.

 

[Johnboy]

The Old House Store do a tub of stuff called 'Conservation Filler'. I am not sure what it's like as I have never used it but it might be worth a look. Probably find it's Polyfilla with a posh name :lol:

 

[Penners]

Welcome.

I'm afraid I know little about lime, but I just wondered whether you'd be available for a stag party.

 

[TheStripper]

Dear all

Thank you so much for your responses: i do appreciate the time and effort taken.

They are equally informative and varied!

Please see beam/ laths in question:

Will remember to call them 'laths' from now on! Thanks for correction, but bear in mind these were known as 'them thin planks' in our house till a few months ago. I'm on a steep learning curve.

MatthewC- thank you for your kind offer of bargain plaster but I'm a long way from you as I'm near Canterbury.

FamilyWiggs: rest assured I have been sparing with the sander, using mostly where beams were shockingly worm-eaten and crumbling in order to provide some sort of surface for final finish (i'm thinking of lime waxing).

Johnboy- I like the sound of 'conservation filler' as potentially a half-way house between using Polyfilla (too easy) and proper lime plastering with the 2/3 different layers and lots of equipment (too expensive). I should have mentioned in my post that I'm flinty.

Penners- hmm, sorry no immediate plans to do Stag parties. I'm in need of tidying up almost as much as my beams: some judicious sanding and filling might return me to my former glory. Till then, the stripping best done indoors, ta.

 

[Keithj]

Greetings!

Sorry, I've not been around lately to add my penn'orth to the poundworths of advice you've had.

I'm in a 15th Century house, now finally all restored - for now!

We had a brilliant lady to teach us what we had and the do/don't list.
She left us a little pot of lime putty to fill the gaps and cracks as the green oak used for repairs shrank. It is easy stuff to work with (just as easy as polyfilla in my book).
We don't mix sand in for these repairs. The only catch is the need to cover it with damp cloths for a few days after applying it, to allow it to carbonate.

You may get hairline cracks in it, but when you limewash it, the lime in the wash neatly fills the cracks.