AAAAAAAAAAAaaaaargh

[kiwipaul]

I'm not a plasterer. However I had to learn pretty quickly after we ran out of money halfway through a renovation project. M<anaged to do the hallway ceilings and walls and after a thorough sanding afterwards I think it looked pretty good. LOOKED pretty good.

I'm putting the 2nd coat of paint on now and a big lump of my skim has just come away on the roller. Help!

Alright, a bit of info: It's a masonry background with lime render and an old, yet very sound skim over the top. Then my skim is over that. The old stuff is quite solid although it does make a funny noise when tapped also, quite hollow in places. The majority of it is very good.

Have I not put enough PVA when I skimmed or is there a fundamental problem with the wall that I haven't addressed? Can I do anything about it without having to take the whole thing down? Do you think the bank will understand?

Any advice appreciated. Cheers.[/i]

 

[dougalhouse]

I'll try to help but can you answer these questions first:-
1.) How did you prepare the walls prior to skimming?

2.) How many coats of finish did you apply?

3.) Was it definitely just your new skim that came off?

 

[greengrass]

Firstly you say it make a funny sound then say it's hollow in places. Well it sounds like the funny places are beginning to get to the sound of being hollow. It pays to do the job properly and cut all hollow/ loose original off back to the masonry. However if the area that peeled off with the roller was applied very thin then it could be you haven't left it long enough before painting. wetting it with stick paint will pull it off.

Preparation is the key to a good job: Too late now unless you take it all off, but next time if it is hollow cut it off if it sound funny cut it off as it's most likely ready to go 'live' that is pull away from the wall and sound hollow. Walls that have hollow spots oras you put it funny sounding spots really need to be stripped and fresh coat all over, and not paster over old stuff, that's called 'bodging'.
Method taught to me by a MASTER plasterer.
Strip the wall back to brick/blockwork. Coat wall with mix of 1 part Unibond or any other quality PVA adhesive to 5 parts water. Throughly coat the wall and allow to dry out. Coat the wall again with 1 part to 3 parts water when tacky to touch it's ready for plaster. Apply a backing coat of Bonding plaster, If you want to fix up right battens to the wall and plaster wall in sections. Get all battens level with one another this will ensure the backing coat will end up flat. Remove battens before the plaster sets and fill in the gaps. You can then skim the backing coat while it's still damp as this will slow up the finish coat setting time.
Apply both backing and finish plaster with a wooden float you will find it lays flatter as metal floats flex leaving a wall hilly.
when finish coat has set polish it with the metal float and plenty water flicked on by brush in front of the metal float drawing it up the wall.
If you haven't put enough PVA on a wall it usually shows by 'Crazing'.

Remember plastering is a two many job as each mix must be done in a clean bucket. Any plaster from the previous mix left in the bucket will send off the next mix quicker. You can tell why by holding a wet piece of plaster and feel it getting hotter as it sets. That heat send the new mix off quicker.

 

[toxictoad]

Do you think the bank will understand?

The bank will always understand...if you can pay it back

 

[kiwipaul]

Just figured out how to find your old posts on this site. Thanks for the replies. I ended up tearing a load of skim off the wall and filling it with some ready mixed filler, gave it a sand and painted it again and it looks alright! Put some PVA on first so it would stick.

Thanks alot for the tips.