how much old plaster to remove

[mneto]

Hi there,

I'm a complete novice and am mainly going by instinct. Please help.

An internal wall in my warner flat (1894) had a hollow section by the ceiling, it didn't seem like a lot of plaster needed to be removed because most of the wall didn't sound hollow and there are no cracks. However, as soon as I started to take out the hollow bit I realised that all the plaster was coming off easily even where the wall sounds fine. Under the plaster there is a dark grey mud with horse hair. there is no signs of damp and like I say, the wall doesn't sound hollow but the plaster still comes off easily. Shall I leave it and render and skim or take it all off?
hope this makes sense and thank you in advance you guys are amazing! I have read so many posts and have already learnt alot.

Please help, really lost on this one and really can't afford a plasterer.

Thanksmneto

 

[Lower]

We've had every room in the house re-skimmed and i've had a number of walls with blown plaster similar to what you describe.

I always chop it back until i get to plaster that is firmly attached to the wall.

It usually means removing quite a bit of plaster over a much larger area than you first think when you start hacking it away.

 

[opps]

If you definately can't afford to replaster then stop removing any more blown plaster.

Whilst not ideal you can force pva behind the blown stuff- just enough to lock it off (hold it in place) on the edges so that you can patch the missing areas.

Don't reskim the walls after, the plaster could well craze and might even make the rest fall off.

Then cross line the walls with lining paper. The plaster will still be blown but it will be happy for years.

Before I get slagged off by any of the plasterers here, i appreciate that the from a longevity point of view the walls should be taken back to brick but in this case i have provided a solution that will last for years and will be the cheapest option for the OP giving that lining paper is very easy to hang.

 

[joe-90]

Wait until Richardc comes home. He's the Daddy.

I'd hide behind the sofa if I were you.

 

[Richard C]

You’d have done better to have posted the plastering forum with this one. If the plaster sounds hollow it’s blown but if not cracked & crumbling, it can stay up there & intact for a surprisingly long time. Once you start poking it about, things go from bad to worse & it really has to come off or it will fall off of it’s own accord eventually.

One thing you need to be aware of is that if you remove more than 24% of the plaster from external walls, you will be changing a thermal element as far as Building Regulations go which could result in you having to upgrade the whole of the wall insulation to current standards if you get found out. You’re hardly likely to get caught by your LABC unless having other building work inspected but just be aware of the rule.

You need to be very careful with old properties; single skin walls have to be able to breath; they may not feel damp external walls will absorb moisture but they must also be able to give up that moisture. Using inappropriate rendering materials or plaster, which will not tolerate damp at all, could result in you creating a whole load of new problems rather than curing the one you have.

You ask about DIY but you need to think seriously about that one; simple re-skimming is going to be hared enough for a novice but to attempt a base coat & skim will almost certainly be beyond your capabilities unless you’ve had any previous rendering experience & you can’t use a base plaster. Another option is to dry-line the walls with insulated plaster board (to current insulation standards) & skim that. Board skimming is likely to be more within the capabilities of experienced DIY but, again, unless the lining is done properly incorporating a damp membrane you could create all sorts of problems with damp on single skin external walls.

Before I get slagged off by any of the plasterers here, i appreciate that the from a longevity point of view the walls should be taken back to brick but in this case i have provided a solution that will last for years and will be the cheapest option for the OP giving that lining paper is very easy to hang.

Now come on who would do that ; disagree & criticise maybe but, under the circumstances the OP posted, I would agree the best advise is don’t go any further & even to using bloody lining paper, at least it will hold it all together for a while.

I’d actually composed my post “off line” before I’d even seen yours so I’m being genuine here!

 

[opps]

Am applying for the witness protection scheme as we talk...

Edit--------------------------------

Blimey richard didn't b*slap me...

To the OP

Lining paper might give you 10s of years extra life. The walls could have been blown for dozens of years.

Ceilings in a property as old as yours are a different kettle of fish. If they are already lined DO NOT strip them. If ever you want to deal with cracks etc, fill and line over again.

I have worked in quite a few houses about 30 years + older than yours where the original ceilings have fallen down in the middle of the night. Fortunately not in any of the bedrooms where the client's family have been sleeping.

Those clients then preemptively overboard the ceilings, screwing straight into the joists to hold the old ceiling up.

 

[Richard C]

Wait until Richardc comes home. He's the Daddy.

Aw shucks joe, youve given me my crown back

I'd hide behind the sofa if I were you.

Na, had some good news & in a good mood tonight

 

[Richard C]

Am applying for the witness protection scheme as we talk...

You also compile "off line" I see

 

[opps]

either that or I type awfully slowly

 

[Richard C]

Blimey richard didn't b*slap me...

Horses for courses M8, it's all horses for courses . I could never condone lining except as a last resort for someone like the OP; it’s all too often used as a quick fix to cover a multitude of sins by folks wanting a quick fix & looking to shove a problem onto some poor unsuspecting soul who won’t know any better or cant spot it! It’s this approach that really piesees me off.

 

[roughcaster]

piesees me

and Sagittarius me!!

 

[Richard C]

and Sagittarius me!!

 

[mneto]

thanks to all of you for your advice and very entertaining banter

I have taken it all back to the brick, it was just all too crumbly. I'll have to try to replaster myself if that doesn't work I'll sell the family's silver and hire a plasterer

thanks everyone!

mneto