multi finish over lime putty

[niceandflat]

I am planning to reskim my old ceilings in my house and they're lime and lath. Would it be better to skim with multi finish or a smooth lime putty?

I am also going to knock off some browning at low level on some walls to redo a damp proof course that has failed. I only noticed the damp patches a few years back coming through the browning plaster, I didn't notice it with the old black lime. It must have held it back, by the way how did they make the lime black, did they dye it? Because its normally white.

So I'm thinking of re plastering it with lime lite as a backing coat, so will it be better to skim in lime putty or multi finish. ie Does multi finish breath at the same rate as lime putty, or will it start to crack and drop off after short time?

 

[mayti]

multi finish wont let it breath

 

[mayti]

sounds like your wall not breathing correctly in first place maybe the browning causing moister to be traped in the wall lime walls need to breath so using correct lime morta helps

 

[niceandflat]

So I take it that multi finish/gypsum isn't reccomended on lime and lath or any other lime background? Would lime putty with a drizzle of plaster of Paris be more suitable?

 

[niceandflat]

So would only lime putty with a drizzle of plaster of paris only be suitable for lime backgrounds in general to maintain flexibillity? And gypsum would seal it and maybe cause cracking on lme and lath backrounds.

 

[lucius]

Iwouldnt be putting plaster of paris in the mix you wont have time to get it of the hawk onto the wall never mind finish it, try googling lime plaster for some info you should be only using one or the other pure lime mixes and gypsum dont go together.

 

[mayti]

I am planning to reskim my old ceilings in my house and they're lime and lath. Would it be better to skim with multi finish or a smooth lime putty?

I am also going to knock off some browning at low level on some walls to redo a damp proof course that has failed. I only noticed the damp patches a few years back coming through the browning plaster, I didn't notice it with the old black lime. It must have held it back, by the way how did they make the lime black, did they dye it? Because its normally white.

So I'm thinking of re plastering it with lime lite as a backing coat, so will it be better to skim in lime putty or multi finish. ie Does multi finish breath at the same rate as lime putty, or will it start to crack and drop off after short time?

look at ty mawr lime good website for you to look at for lime information

 

[spunky]

Limelight do their own finish

 

[alf]

if your house is plasterered in lime then lime should go back on. browning or any of the gypsum plasterers are no good and this goes for the damp proof.....

knock it all off and use nhl 3.5 or if you want high impact use nhl 5. nhl 5 is usually used in exposed areas and is stronger.

any more indepth help you can always send me a pm.

 

[andyR]

i'd knock all the browning off for sure, i assume u have a solid wall construction from the use of lime plaster, browning is no good at all, it doesnt let the wall breathe as alf says. Then id use Dri coat as a backing plaster, Sod putting lime back on, takes too long. If yr leaving any lime further up the wall away from yr damp course bond-it over than then skim the lot with multi. This is what i was taught and its also what BG tech suggest when faced with the same issue.
As to your ceiling id not put modern gypsum over the lime, lime contracts and expands at a different rate to gypsum and will crack it in no time, so either lime over or board over n skim.

 

[spark2010]

lime putty? thats hydrated lime mixed with water and allowed to hydrate for 6 months?? u wouldnt use that... its NHL u need like alf says

 

[spunky]

Skim it it's a ******* ceiling it doesn't need to breathe

 

[niceandflat]

Thanks for the replies lads and lasses.

 

[ciderlover]

re board over the top and skim, job done

 

[higgs3]

Use Ty-mawr lime finishing plaster or similar on the ceilings not multifinish, you will need to score the existing lime plaster with a devil float to create a key, then make a slurry coat by watering down some of the lime finishing plaster. Paint this onto the ceiling and when dry skim two coats of lime finishing plaster onto ceiling. As for walls get rid of browning it will only cause damp problems by not letting the wall breath, replace it with a mix of 3.5 hydraulic lime and washed sand mortar you will need horse hair or synthetic fibres in this mix. this would be by far the best solution maybe not the cheapest but the best for the building and yes the walls and ceiling do need to breath thats what lime does if you want damp skim with multifinish.

 

[Arti]

Skim it it's a ******* ceiling it doesn't need to breathe

:RpS_laugh: always the voice of reason :RpS_laugh:

 

[sliemasteve]

Use Ty-mawr lime finishing plaster or similar on the ceilings not multifinish, you will need to score the existing lime plaster with a devil float to create a key, then make a slurry coat by watering down some of the lime finishing plaster. Paint this onto the ceiling and when dry skim two coats of lime finishing plaster onto ceiling. As for walls get rid of browning it will only cause damp problems by not letting the wall breath, replace it with a mix of 3.5 hydraulic lime and washed sand mortar you will need horse hair or synthetic fibres in this mix. this would be by far the best solution maybe not the cheapest but the best for the building and yes the walls and ceiling do need to breath thats what lime does if you want damp skim with multifinish.

Why does the ceiling need to breathe? Why does any background which is dry need to breathe? The need to breathe as I understand is to allow moisture to escape.

 

[mark ross]

Limelight do their own finish

Yes they do Spunk, used some in Chiswick this year ona a reno. You would love it, one coat and 2 trowels , job done. Not to be closed up too much as this will stop the system from breathing, so Tarmac say.

 

[Rjb]

lime putty? thats hydrated lime mixed with water and allowed to hydrate for 6 months?? u wouldnt use that... its NHL u need like alf says

Lime putty is the skim coat mixed with silver sand,the NHL 3.5 mixed with sharp for the backing coat,very good for damp problems.

 

[martinemj]

Yes they do Spunk, used some in Chiswick this year ona a reno. You would love it, one coat and 2 trowels , job done. Not to be closed up too much as this will stop the system from breathing, so Tarmac say.

have seen some try to finish high impact same way as multi ....smooth finish

as you say reduced the ability to breath ..

we finish with a sponge to keep the finish slightly textured.....(although this finish finer than lime finish)