Levelling up old solid stone wall

[nick0601uk]

Hi there,

Newbie so apologies if this has been asked a million times before or seems like a daft question...

I have an old house (about 200 yrs old) solid stone and lime ( and maybe even cob in middle) walls about 45 cm thick, I'm wanting to make flat and level 2 lime plastered downstairs walls, one is external north facing with approx 3 ft of wall below ground level, dreaded cement render onoutside ( not looking to remove at the moment as it is sound)...not possible to resolve ground level either as other side of wall is neighbours garden, , other wall is internal shared wall with abandoned old house.. I'm not interested in insulating the walls as it seems such thick walls are insulation enough on their own if dry. ( im not sure ours are totally dry but they dont seem too bad at the moment...the issue is they are not in best condition, as well as bending and warping both vertically and horizontally by up to 13 cm in places, bulge in middle etc.. all I want to know is if anyone has had similar situation and put up plasterboard stoothing wall with vents top and bottom to allow wall behind to still breathe and not become damp... or if no one has done this, does it seem a feasable plan...am open to any suggestions really, apart from stripping back to bare stone and starting again as I believe the bulges etc are due to how wall was built...great lol ..thanks for any advice or suggestions

 

[elizabeth]

Hello Nick, welcome to the forum, hope you find this site very helpful.
We had a similar situation, stone and cob cottage, end wall 3ft underground with neighbours garden on the other side. Cottage was covered in inappropriate materials, cement render, gypsum plaster, horrid black jack and cement floors. The wall inside had blown gypsum plaster and smelt damp. Thankfully the walls were well built and were intentionally built into the earth bank.
We corrected the materials for traditional lime, and built a retaining wall with French drain on neighbours side after removing a horrific concrete strip previous owners had put in to combat the damp.
What I fear you may find if you covered the walls with plaster board even with a gap and vents, is that you will exasperate the problem of your bulging walls as it maybe hiding the symptoms rather than solving the problem. On the other hand, if you have no issues with damp in these walls and time and money is needed elsewhere than cosmetically a board in front is temporary solution.
If your walls have original lime plaster still then air flow to the face of the wall is important.
I’m only going by my experience, others may have other suggestions. But if you need to ask be happy to help with advice.

 

[malcolm]

I've used an internal plasterboard wall on wood studs with a gap to the external wall that is ventilated to the roof space. Insulation between the studs then plasterboard on top because once you are connected to the roof space you are outside. I did it mostly so I could remove the exterior wall and keep the room habitable. It was a timber frame on the outside. Works well and I did the same downstairs. My timber was green when it was installed and now has gaps but it is not on the priority list as the water that occasionally gets in can breathe out through the exterior wall or get ventilated to the roof.

 

[88v8]

.... I'm wanting to make flat and level 2 lime plastered downstairs walls

Hello

Why do you want to make them flat and level?
The bulge and wave are part of their history.
Making things flat and smooth and straight and level, destroys the texture of a period house.

If you want to lime-plaster them, they do not need to be remotely smooth. You can apply single-coat haired plaster with a float and profile it to the wall with a churn brush.

Ivor

 

[TudorCottage]

Our spare bedroom had an unsightly hole in one corner where heating pipes had been channeled. I started to try and tidy it up and suddenly had a hole approximately 2ft by 2ft :shock:

A bit of you tube research and I’ve put in new laths, 2 coats of lime mortar and a finishing coat of lime plaster and I think it looks good.

I’ve never plastered anything before but I’m chuffed with the results, even if I do say so myself

As has been said, perfection really isn’t required on these older properties and if anything my efforts are a lot smoother than the rest of the room.

 

[nick0601uk]

Thank you all for taking the time to reply, your comments have helped me decide no plasterboard required, and its not even necessary to square them up and level them...next step lime plaster I suspect, and yes, I will be giving it a go myself

This does lead me on to another line of thinking and more questions though.... lol so if any of you have any answers/thoughts I would be more than pleased to hear them, learning all the time..

In a nutshell the existing lime plaster seems mostly sound, and I would prefer not to take it all off and start from scratch so can i apply new lime plaster over the top of this somehow and how thick a coat could I apply at each attempt.. is the finsihing coat a different beast from the 1st coats? would nhl 3.5 from St.Astier be suitable, or do I need to look for something else?

Sorry for so many questions, I will visit Youtube as well, promise :lol: :lol: :lol:

 

[nick0601uk]

Thanks for the info, all the suggestions and information given has been a great help, at least now I know where I'm going, no plasterboard now, but it looks like I'm about to embark on a new lime plaster adventure...new skills are always handy though so I'm looking forward to it, thanks again,

Nick

 

[MatthewC]

Hi Nick

I would suggest that if a wall has cement on the outside it is even more important than usual that the inside has as much ventilation as possible. If the wall is dry you want to keep it that way, and boxing it in will inevitably increase the chance of damp retention (even if you think the gap is ventilated). As Ivor says, I would live the the bulges which are part of the character of the house (I assume you deliberately bought it with character?!).

You need to speak with the neighbours and at least remove the cement render at the bottom if you can't do the whole lot. The best thing I did on my house was to lower the ground level all around and let the walls breathe.

Matthew

 

[88v8]

In a nutshell the existing lime plaster seems mostly sound, and I would prefer not to take it all off and start from scratch so can i apply new lime plaster over the top of this somehow and how thick a coat could I apply at each attempt.. is the finishing coat a different beast from the 1st coats? would nhl 3.5 from St.Astier be suitable, or do I need to look for something else?

Yes, pointless to remove good plaster.

If you do a forum search for 'lime plastering' you will find quite a few hits...
This one https://www.periodproperty.co.uk/forum/viewtopic.php?f=1&t=17245&p=232119&hilit=lime+plastering#p232119 mentions a couple of skim (finishing) products and sources.

As I had done no lime plastering before I plastered a whole, very uneven, wall, I took the easy way out and used readymix in tubs from Traditional Lime https://www.traditionallime.co.uk/products/traditional-lime-products/lime-plasters but I was able to collect so that kept the price down.

One thing that is important, is wetting the wall thoroughly before you start, then damping the lime while it dries. It's not fire-and-forget like gypsum. The initial wetting is to ensure the lime calcifies fully, and the misting is done to avoid cracking. I kept up the misting, with a hand pressure mister, for a week, consolidating with the churn brush as cracks formed. If you are aiming for a smooth finish, a float would be used rather than a brush, but the principle is the same.

Hopefully someone with more experience will be along to advise further.

Ivor