Skimming an old wall.

[cox377]

Hello All,

I’m currently looking to plaster the walls in one of the bedrooms of my house. It has a few areas where the plaster has blow, I’ve cut thoses areas back and used sand and cement to build it back out to the original lath render level. The house is about 130 years old and the old render under the plaster is very very sandy, above that sandy render is the original plaster skim.

I want to skim the whole wall as there a number of imperfections that have been there since the house was built, I’m assuming. Am I guessing I use PVA rolled over the whole lot. Let it dry, then do another PVA skim, wait till it goes tacky then plaster skim the lot? Do I need any hardwall basecoat?

Much appreciated guys, I’m very novice at this but trying to learn.

CoXen

 

[PrenticeBoyofDerry]

use muliti finish to skim with, other than that you seem to be doing the job right.

 

[cox377]

Thanks for coming back to.

There are lots of holes around the house in the old plaster. Can I confirm, I can repair these using sand and cement. PVA the whole place, then skim with multifinish, without need to use a base coat?

In addition, when reading through these threads, I've heard people talking about using lime plaster, is this recommended?

CoXen

 

[trowelmonkey1]

it's possible that the powdery plaster you have on the walls already is lime based, depends on how old it is really, Cement is a relatively new invention so lime was the material of choice for years.

lime is added in small part to sand and cement renders these days to add a small amount of flexibility to the plaster and improves the workability of it too and does plastciser which is used in sand and cement only mixes.

old school lime plaster has no cement, this is used on sold stone walls as lime plaster will breathe, this is necessary on old stone walls amongst others i should imagine but i'm guessing you don't have stone walls? probably 9 inch solid brickwork.

i think a mix of sand/cement/lime in the ratio of 4:1:1 is probably fine to patch up, PVA the lot as you say and make sure you skrim the edges between the new patches and old plaster as a precaution.

see what some others think to the mix though before you head off to the shop.

oh, and make sure it's plastering sand!

 

[cox377]

Hello, thanks for coming back to me Your right, standard 9" bricks. I'm wondering if doing a full render coat is going to be easier than patching up everywhere.

So I'm right in the fact of.

PVC -> Sand/Cement/Lime ->Multifinish skim.

Secondly, when steaming off wall paper on walls that have PVC behind them, does this soften the PVC and bring the plaster off?

Thanks guys

CoXen

 

[wozza56]

Steaming any wall for too long can make the plaster blow
What are you going to be doing to the walls after you have fixed them ,are you painting or papering ?
I only ask because if you are papering you could save yourself some work and use wickes one coat plaster which is good and flexible and you would obviously be able to do the job in one go

 

[Richard C]

Steaming any wall for too long can make the plaster blow

wozza56 is right; over doing the steamer on any plastered wall will blow the finish skim off the base; use with caution

you could save yourself some work and use wickes one coat plaster which is good and flexible and you would obviously be able to do the job in one go

Na, sorry to disagree but you really don’t want to be doing that. I’ve been told by wiser one’s who’ve been at it far longer than me (not sure if they are older ) that one coat was the way many years ago & it was good stuff. Having tried what's on offer when I first started around 5 years ago, as most beginners probably do, I now wouldn’t touch it with a barge pole, especially on such an old wall; it probably has it’s uses but I would struggle to think of any, IMO it’s god awful stuff.

So I'm right in the fact of
PVC -> Sand/Cement/Lime ->Multifinish skim.

That’s what I’d stick with, as per TM’s advice. But can we also get back to the correct terminology; you were right 1st time, its PVA not PVC

 

[cox377]

Thanks guys.

I'm going to be looking to wall paper.

Bottom line, i'm after a uniformed finish without the worry that evey little knock to the wall is going to cause cracking behind it. This stuff seems so brittle.

Coxen

 

[wozza56]

Richard c ,i have been doing this job for over 20 years and i find quite a few uses for one coat but only the Wickes one especially when a lime plaster could be used as its very flexible and breaths just like lime when dry and its very good for inexperienced people because it very forgiving
yes it doesnt finish as good a multifinish but thats why i asked if it was being papered