Skimming mid 1930's shower room ceiling

[wobbly2]

I'm trying to help a friend redo there (2.7m x 0.85m) shower room in a mid 1930's house. There is a problem with the ceiling in that it had several patches of different types of finish i.e. distemper, paint, emulsion and texture. These have now been stripped off (much scraping and rubbing) and the ceiling is back to its original plaster surface.

The surface is not really in a good enough condition to paint. In some places it is quite smooth and others it's sandy, friable and dotted with gouges, some of which contain remnants of the old paint etc. There are also several cracks.

I guess the best option would be to re-skim the ceiling. I've carried out plastering repair jobs in the past with reasonable success but before I make a start can anyone recommend what plaster should be used and how to prepare the existing surface before applying the plaster.

I've got some Cupronol Cuprotect stabilising solution that I bought years ago and I wonder if this would be suitable to stabilise the ceiling before plastering?

I doubt it makes any difference but just in case it does the ceiling has a skeiling across one third of it.

Any help would be much appreciated.

 

[PrenticeBoyofDerry]

Firstly what condition is the ceiling?
Is it a sound surface to plaster over, not moving, sagging and crumbling?
As the house is of an age, where I would expect the original plaster to be not a good surface to work on, if there are plenty of cracks.
It could be worth considering over-boarding then skimming.

Any way if sound surface, I would get plenty of PVA primer on the ceiling, there will likely be plenty of suction on old plaster, so two drying prime coats, then one coat tacky to touch.
I would tape the cracks with nylon repair tape and use multi-finish as the plaster product.

 

[wobbly2]

The ceiling surface seems quite sound there is no noticeable movement (the cracks appear aged settlement ones and had been bridged with filler and paint without any major recracking, no sagging or crumbling except where it has been over scraped/snaded (loose sandy particles can be brushed off and rubbing the area with a hand after brushing produces no new debris).

I had considered over-boarding but the skeiling to flat ceiling region has a radius of about 150/175mm which I doubt I could successfully recreate over its length of about 2.7 metres.

I had considered taping over the cracks with paper artexing tape and then artexing it.

 

[chappers]

make sure you get all the distemper off, whilst plaster sticks to it OK, it wets up the glue and the whole lot can peel off, even PVAing might not stop that,same goes for any wall paper paste that may still be on the ceiling too. I speak from experience.

 

[Will..]

If in doubt, definitely overboard. For a reskim, I'd use either blue grit or wba for it's key. If you're worried about the radius corner, get a plasterer in.

 

[wobbly2]

Any way if sound surface, I would get plenty of PVA primer on the ceiling, there will likely be plenty of suction on old plaster, so two drying prime coats, then one coat tacky to touch. I would tape the cracks with nylon repair tape and use multi-finish as the plaster product.

Reading around it seems that if I get the PVA mix and or application wrong I could end up doing the job again so I'm thinking to use either Blue Grit or WBA (possible from Wickes), which do you guys think is best. Trouble is both only appear to come in big pots 5 ltr & 3ltr respectively at about at a similar price..

I can't find any nylon repair tape for plastering, only paper or fibreglass plasterboard/scrim tape. These tapes only appear to come in nominal 50mm widths, so if I use it to bridge the cracks I'll have to keep cutting and overlapping it so that it follows the crack lines; is this OK? However, Knauf do a 100mm wide fibreglass tape for there Aquapanel. Also what adhesive should I use to stick the tape down?

I've read elsewhere on this website (but can no longer find it) that it would be better to use a board finish on Blue Grit because it will give me a longer working time. Anyone have any thoughts on this point.

 

[PrenticeBoyofDerry]

I personally have never had a problem with PVA priming solutions when used for plastering.
But if I where given an option between WBA or Blue Grit, I would firstly question whether the area to be sealed/primed is a high or low suction area, do not get confused between priming a high suction and low suction area.

Nylon scrim tape, Wickes do or used to do one, I think they mat brand it as a repair tape. I will try find a link........
They do brand it as fibreglass, same thing/use
http://www.wickes.co.uk/Wickes-Fibr...WB030HEHNz5MCpu-ii9PHFZPJiUmNymKcIaAqIE8P8HAQ

 

[wobbly2]

The surface is mid 1930's lime/sand cement plaster. I don't know if it is high or low suction; how do you tell? Water dabbed on it with a finger soaks in within 2 or 3 seconds and then starts to fade almost immediately in some areas but in other areas the droplet takes about 2 1/2 minutes to soak in. Without wetting the hole thing I think most of the ceiling is the higher suction.

Thanks for the Wickes link.. As mentioned before, what's the best way to stick the tape in place? Would the Blue Grit be suitable?

 

[PrenticeBoyofDerry]

Sounds like high suction, so I would personally apply 3 coats of diluted(1 part pva-4 parts water) PVA. Let first two coats dry completely, then the third coat to go tacky prior to applying plaster.
The scrim tape linked, is self adhesive.
WICKES FIBREGLASS PLASTERBOARD REPAIR & JOINTING TAPE 90M
Product Code: 163566

• Width: 48 mm
• Material: Fibreglass Mesh
• Length: 90 m
• Colour: White
• Type: Jointing Tape
• Interior or Exterior Use: Interior
• Self Adhesive: Yes
• Brand Name: Wickes

Strong, flexible self-adhesive fibreglass mesh tape for covering drywall joints prior to texturing and finishing