Stripping back to Lime

[GPHouse]

Hi all

So, quandry of the day...

I'm still stripping back the house I moved into on late Nov and despite the fact the whole plot looks like a view of 1990s Beiruit... I think I'm making progress.

I'm in the process of removing cement plaster from few walls back to the lime underneath - there has been some damage due to water ingress.

The wall constuction appears to be rubble filled wall with lime and or clay mortar, clay base cost on all walls, lime with hair... and then the owners have added a beaitiful and massively uneven coat of cement plaster... Lovely.

So 2 questions.

1. I;m going to strip back to the lime, scrub and key the surface, apply D27 and then add a couple of new coats of lime (Base and top cost). Anyone see a problem with this?

2. The ceiling. The original lath has obviously been removed and there is a perfetly acceptable cement rendered ceiling in each room. but... for breathability and joingin with the new wall purposes, does this need to come out, whats the consensus?

Hoping someone can give me a definitive yea or 'don't be stupid'!

G

 

[plasticpigeon]

I can't imagine that the ceiling is cement! Is it not plasterboard and gypsum? I don't think it is necessary to strip down the ceilings, as I don't think having a ceiling that water vapour can pass through is particularly useful. If they look acceptable, then save yourself work, expense and agro and save your efforts where they will do the most good. What is D27? Does your house have a damp proof course? I'm guessing not if it is 230 years old!

 

[GPHouse]

Hi
Thanks.. Definitely skimmed, on what seems to be a mesh taked to T&G. All seems to be pretty solid but may just remove it and board it.

Maybe a modern equivalent of lath and plaster!

DG27 is a Lime primer - used for making it easy for new lime to bind tot he old.
https://www.mikewye.co.uk/product/dg27/

 

[plasticpigeon]

that is interesting. I've never seen that but then I am no surveyor, just an enthusiast. Mesh onto t and g. That sounds like a lot of effort. I wonder why it was done that way. It coulkd be quite a high quality job. Maybe others will know. Anyway, if it is solid and presentable it sounds that it needn't be taken down. Have you got pictures?

 

[mims&pip]

I guess you mean gypsum as opposed to cement on the ceilings? We've restored Tudor, Georgian and several Victorian houses that have all been defiled and butchered by previous owners, but have never come across cement ceilings :shock: We've also never had to replace a ceiling.......until this house, where some idiot put their foot through a second floor lath and plaster (along with a copious application of woodchip) ceiling when emptying the place before we purchased......all of the other twelve ceilings here (despite the woodchip we are currently in the process of carefully removing) are salvageable. No way would I want to take a ceiling down unless absolutely necessary!

Edited to add: the previous owner of our last house (Georgian ashlar stone) had put up some faux beamed walls - very authentic in appearance, fooled many people including our experienced architect - that he had finished with a rough coat of cement over mesh, but I have still yet to see this treatment in relation to a ceiling.

Mims x

 

[GPHouse]

I'll try and remember to take some photos. It's just one room but the previous owners have from multiple excavations, made a hash of most things.

They survey pre-purchase refrenced a 'DIY stable door' (internal door sawn in half and used as an external door) and a 'failed lean-to' (a structure with primary stability and strength added by polystyrene tiles and parts of an Ikea desk).... No joke.

I'm getting used to finding random stuff, last night I found the lath partition walls have been stuffed with old T shirts and the concrete outside the back door was laid on broken glass, a tv aerial, crushed cans and a few shampoo bottles....


This place is genius.... hence why I'm stripping back so far!

 

[livias]

Lime primer is .... limewash. I spex mike wye had added something to it to make it 'his' but limewash works perfectly ok so save your money

 

[plasticpigeon]

Wow, sounds worse than the first builders I employed. I wonder what else you will find. It seems the house is in safe hands now.

 

[GPHouse]

Thanks Livias... will give it a go, considerably cheaper!

As for safe hands.... I'm not so sure, maybe just less maverick.... there is something to be said for the avant garde juxtaposition of ikea desks as a structural and decorative material ...

 

[MatthewC]

GPHouse - if you have mesh are you sure it's on the whole ceiling? That's a standard modern bodge to repair a lath ceiling where they can't be bothered to do the job properly, so where you have found mesh could be just a repair. Modern gypsum & plasterboard on downstairs ceilings is probably fine in my view, but upstairs I wanted the ceiling to breathe (with sheepswool insulation above), so that was where we removed the failing lime plaster off two lath ceilings... it's a VERY messy job - think of the dinner scene in "Carry On Up The Khyber" and muliply by ten!!

Lime primer is .... limewash. I spex mike wye had added something to it to make it 'his' but limewash works perfectly ok so save your money

I used DG27 - its not a lime product; its purpose is to help a new top coat plaster attach to the old (retaining breathability). Where I had removed the complete thickness of plaster from lath or brick on part of the wall, we applied a couple of coats of mortar, then DG27 was applied to the old plaster and then the whole wall had a skim of fine lime plaster. I don't think the fine plaster would have attached properly, even with a limewash base, as the old fine plaster was very smooth, and I was concerned that scoring the surface might have caused more damage.

 

[GPHouse]

THanks. Useful

As said it's just this one roof and the previous owners were a liability. I'd say it's a bodge.

The other ceilings (in half the house only - the other half is vaulted and as yet uninsulated!) are it seems board/plaster , the walls lime. I will be sheeps wool insulating at some point when I can afford theremafleece!

The partition walls between the 3 rooms on that side of the house are lath with lime and are uninsulated inside - the void runs into the roof space and is about 4 inches wide

On this basis, would you remove the board on the ceilings and redo it in lime? will the permeability of the gypsum make a diference is I maintain breathability up through the partitions?

 

[GPHouse]

Oh - and ive already taken a large lath ceiling down... I'm still finding black soot/dust in every nook and cranny...

 

[MatthewC]

The partition walls between the 3 rooms on that side of the house are lath with lime and are uninsulated inside - the void runs into the roof space and is about 4 inches wide

On this basis, would you remove the board on the ceilings and redo it in lime? will the permeability of the gypsum make a diference is I maintain breathability up through the partitions?

My lath walls were fairly structural with a significant frame (4" x 3") which included the top and so the gap between the two lath sides did not go into the roof space - it was all enclosed.

However, as effectively impervious modern materials inhibit ventilation, I was determined to make sure that the bedroom had a natural path for the passage of moisture, which is why I re-plastered the lath (after significant repairs). If you have a gypsum plastered ceiling, even if the void does extend to the roof space, I would think that you might add (in a small way) to a ventilation problem. Having said that, I'm not sure I would remove the ceiling if it's "perfectly acceptable", unless you regard it as your final home for the next few decades and want everything to be done right first time. NB Do your ceilings still have the lath and lime plaster above the plasterboard?

 

[GPHouse]

Hi

Looking from above I dont think so... I think the bodgers used Pine T&G panneling in some areas, and plasterboard in others....

I think i've come to the conclusion, following some further stripping back of walls that Im going to do the following:

1. Leave the ceilings with plasterboard and standard modern render alone.
2. Remove the bodged cement/scrim bodge job ceiling
3. Remove thelath on the partition wall and board it with Celenit, followed by some lime... or some board/lime combo
4. Strip back the other walls and use DG27 and skim with new lime

Bit of a ball-ache.... but i'd rather walls/plaster doesnt fall and while it;s a livable construction site I might as well rectify it.. better now than later!

Thanks

G