Plastering advice - 4 walls, all different, plus ceiling

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Could do with advice on how to get the 4 walls of my lounge plastered. I'm not doing the work myself, but wanna know what to ask for, and don't want talking into something unnecessary. I want the finish to look smooth & crisp.

Annoyingly, each wall is a 'special case' - nothing's simple! The house is a small victorian worker's terraced cottage. Please help.

1. Exterior wall

This has got a bay window, and the bottom 1m has been replastered with sand & cement, I suspect following a damp course. I've hacked the lime plaster off above it - can I just butt up to this S&C plaster with new plaster, and what sort?

2. Party wall with chimney breast

This wall has still got lime plaster on. It will come off easily, but I want to put soundproof boards on this wall and then plaster them. Is there any point to hacking off the plaster first (other than gaining a couple of centimeters)?

3. Internal wall (staircase behind)

This wall's really thin and has wood within the brickwork. The bricks have been used on their edges?!
This originally had lime plaster put straight on it (which fell off pretty easily). I'm pretty sure you shouldn't plaster directly onto wood like that? What should be done instead? This is the wall I'm wondering if Dot & Dab would be better?

4. Internal stud wall

This was lath & plaster (which I've totally removed) on a stud wall. Was gonna do a simple replace with plasterboard, but wanna add some soundproofing, somehow. What would give me good results without being too expensive? I'm gonna replace the wall on the other side of the framework later, if that makes a difference.[/b]

5. The ceiling
Someone's took the plaster off the ceiling but left the lath, and nailed boards over the top, skimmed and finished it with textured paint(!). You can see each board's edges (as if they're convex) and it looks megashit. Can this be skimmed over?

 

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No one got any sound advice??


Here's a couple more questions. On this exterior wall it needs a damp course, so all the existing sand and cement plaster is coming off. I'm looking into dot & dabbing Thermaline straight onto the bare brick afterwards for the whole wall and bay.

Is it worth going for Thermaline Super rather than the standard? (It's more than twice the price, but the 30mm thick claims to offer twice the insulation as the standard 30mm board)

The wall is 2.6m high in total. Boards are 2.4m. Would I be OK to just add a 10-20cm strip at the top/bottom? Or will I need to I cut two boards so they join in the middle of the wall? (this affects how many boards I need to order)

 

[Watshot]

No one got any sound advice??


Try posting in the 'plastering' section?!

 

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Thread moved.

Any plasterers with expert advice, please speak now.

 

[NickB_99]

Not an expert will bit get you going with some comments -

Firstly, standard advice with asking for quotes - go off personal recommendations, try to see examples of their work etc. Don't just go off price!
You have a mixture to resolve here and in a victorian property, so need good quality advice. Plastering is more than whacking a coat of finish skim on top of dot & dabbed standard wallboard plasterboard. You need good advice.

1 - if it was lime on it before, then that is probably a hint what is probably best to replace. You could argue, complete the rest of the wall with sand/cement/lime render (which would match what's at the bottom and reduce cracking) - but I'm going to bow out and let the pros argue this one.

2 - If the lime comes off easy, you clearly don't want a re-skim straight over it. You could apply sound proof boards if you wished, but would need good mechanical fixings. Don't just D&D on a loose background. But again, if it was lime there originally, do you get it replaced with the same.

3 - again, if it was lime removed... Where there is wood, can always fix metal lath and the plaster will stick to it fine. The wood doesn't force a D&D solution.

4 - Probably could fix soundbloc plasterboard as you suggest, assuming a sturdy frame. See the british gypsum site link in the Plastering wiki.

5 - With a sound ceiling, yest it can be reskimmed. However, if you can see board edges in 'waves' then it doesn't sound well boarded. May be possible to add more drywall screws to tighten it up. Or it may be necessary to bite the bullet and either overboard with new 12.5mm standard plasterboard and screw through into joists or take down what's there.
Note - a lot of mess if you take down. Also, some older artexes can contain asbestos, so need to be careful on dust generated from the coating.

I may have advised a bit outside my comfort zone of what I've done personally, but hopefully should get you going on your thread for some decent debate.

Good luck!

 

[1john]

Is the floor concrete, flagstones or suspended timber?

 

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Suspended timber. Approx 8-10" gap under the floorboards, soil base.

Regarding replacing the lime plaster with more lime plaster, is that necessary? I'm not precious about the victorian-ness - the house has not one original feature left in it (apart from maybe all the plaster that I just hacked off, lol).

 

[1john]

if that wall partitioning off your stairs is built ontop the floor you can d&d it

the wall that you removed lathes from can be plasterboarded

your external walls need to breathe as they are lime mortar and you have no DPC in your property, encasing the bottom 4" in cement traps the water in there hence the advice to put lime back, it breathes and allows any moisture that comes into the wall to evaporate.

Cement or even gypsum plasters do not fare well over timber, the timber gets wet on application and expands, it all dries out and shrinks again, cracks appear. There are ways around this, the most effective I have seen was to fix plasterboard strips over the timber so as it protrudes into the adjoining brickwork with about a 2" overlap, two coat render to flush with the plasterboard and skim over the lot, thats if you decide youd like to use cement render.

You could batten and board the external wall, put the rip at the top in my opinon, less likely to risk popping the skim up there and more likely if its at the bottom, especially when applying skirting boards.

Im tired so dunno if I have answered as much as I can but hope this helps some what.

 

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The partitioned staircase wall goes below the floorboards and sits on the base soil, is that what you meant 1john?

Would using metal lath over the timber in the way you've described using the plasterboard strips work as well?

As I mentioned in my later post, I'm getting a DPC put in on the external wall. Do I definitely need lime plaster in that case? I was quite taken with using Thermaline on it to keep the place warm - is this gonna actually cause problems?

 

[1john]

Exactly what I meant about the wall partitioning off of the stairs.

Eml stops the render falling off when it cracks along either edge of the timber, ive seen it fail with eml in and the eml keeps the material in place but in moves slightly cos of the lack of bond, not that it always fails but having seen the plasterboard method and never seen cracks anywhere with it, i'd say its a better bet in my opinion.

The thing to remember with your house is that it isnt designed to have a DPM, nor does it need one with lime plaster. I wouldnt D&D over anything thats had alot of moisture in the wall recently, the dampness will bleed through the dab and into the board. If you want plasterboard I would batten board. I personaly cannot see any problems with this method.

 

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What's the minimum width of battening I could get away with?

There's architrave around the window frame, plus the sill, that in places is barely a centimeter proud of the existing plaster.

It'd mean I'd have to go down to 22mm thermaline, and even that I'm guessing would be pushing it in places.

If I had time to wait for the brick to dry out (I've read 100 days is average?) after the DPC, would D&D be ok then?

 

[1john]

The architrave thing is easily sorted, whip it off and tack on a bit of timber suitable to bring it flush with what ever you decide, you can either remove and replace the window board or simply stick a new PVC one over which you can make longer.

Battens 2x1 tanalised roofing batten is ideal, you can fix this at 600mm or 800mm centres with 4 or 4" tapcons into the bricks, use plastic packers to make the wall as true as you like, the void between the battens and the wall can be foamed up with low expansion foam for a bit more ridgidity. Use a 4x1 along the floor and you can fix your skirting boards easy cut in noggins through where a board ends, typically 2425mm to center of noggin from the floor level if the floor is fairly flat this allows you to keep the board 25mm off of the floor, which incidently is the thickness of two bits of plasterboard.

When you use this method it leaves an ideal service void for pipes and cables, if your electrics are old you are best getting them looked at now, alternativly you could faff around running conduits in the void which could be found later with this method as it would be a shame to have all this work done and discover your house needs rewiring afterwards. ( im a sparky too)

 

[Possel]

Regarding replacing the lime plaster with more lime plaster, is that necessary? I'm not precious about the victorian-ness - the house has not one original feature left in it (apart from maybe all the plaster that I just hacked off, lol).

Yes, but you might find that the house responds better to being re-plastered with lime, not all this modern stuff. The difference is that lime mortar is breathable and so dampness is naturally controlled, but modern stuff is all impervious and so retains water in the walls, which then tries to get out somewhere else. Basically the two types of construction are incompatible and if you do modern on the old then you are likely to start chasing the symptoms of a dampness problem which was caused somewhere else.

Try googling for "period property" + dampness and have a good look at what you find. Then at least you should be informed enough to still be happy with your decision to avoid using lime plaster. (or perhaps you might have changed your mind!).

If you want to see my credentials then have a good look at my blog http://houseintheenchantedforest.blogspot.com/. In the last year I have changed a cold pile of stone and damp wood into a lovely warm and dry house without using cement etc.

NB That wall with the stairs behind: you say "This wall's really thin and has wood within the brickwork" Actually of course it's the other way round - it has bricks (infill) within the woodwork (the structural item). And you say you have no original features left...

 

[zbed]

lol... yes, I realise now that the wood is the structure in that wall. It kinda freaks me out, I've lived in loads of victorian terraced houses, but never one like this!

So is lime plaster/plastering more expensive/more expensive to get done than modern stuff?

Can you get as smooth a finish with it? That was ultimately why I couldn't wait to get the old stuff off, it looked like it was put on by Stevie Wonder.

Also, I've just cut the lime plaster of this internal party load bearing wall. The Wall beneath's a shocking site, the plaster in some places was 40mm thick, in others less than 10mm (where bricks stick out).

I assume it would it be best to put lime back on here?
It's full of holes and deep crevices, do they need filling in first, and what with?
Is it really ok to put 40mm of plaster on a wall? (cant see as I've much choice!)

 

[peaps]

lol... yes, I realise now that the wood is the structure in that wall. It kinda freaks me out, I've lived in loads of victorian terraced houses, but never one like this!

So is lime plaster/plastering more expensive/more expensive to get done than modern stuff?

Can you get as smooth a finish with it? That was ultimately why I couldn't wait to get the old stuff off, it looked like it was put on by Stevie Wonder.

Also, I've just cut the lime plaster of this internal party load bearing wall. The Wall beneath's a shocking site, the plaster in some places was 40mm thick, in others less than 10mm (where bricks stick out).

I assume it would it be best to put lime back on here?
It's full of holes and deep crevices, do they need filling in first, and what with?
Is it really ok to put 40mm of plaster on a wall? (cant see as I've much choice!)

You need to find the highest point in the wall. The bit of the wall that stick out the most. Then fill the rest to this level, scratch coat. And no it's not ok to put on 40mm at a time. 10/12 max. Build up your scratch coat until it's plumb then apply the float coat. Use lime.

If you live near Derbyshire we can arrange to come look. No charge.