applying 1 inch think coat of plaster

[reggie13]

Hi,

my staircase wall needs to be replastered. I'm sure its probably an inch thick or more (I have broken off a small piece to check). I will be getting a few quotes from plasterers.

I want to know what is the proper way to build up the wall back to the original depth ?

I've been told that hardwall plaster is the correct undercoat, but gypsum web site says it should only be applied to 11mm thickness.

Should two separate coats of undercoat be applied?
Or should an initial sand-cement (or other render) be applied and then the undercoat plaster ?

 

[gregers]

normally 2 coats then a finish coat.

 

[reggie13]

thanks gregers, how much time should the first coat have to settle before the second coat is applied. Is an hour enough ?

 

[trowelmonkey1]

hour is probably too soon, same day though will be fine

 

[Richard C]

If it’s being re-skimmed anyway, don’t worry about using a finish coat, just build out flush with the surrounding wall with Bonding, Hardwall or even render. I’d do that thickness in 3 coats applying each one after the other has gone off, couple of hours in between but render will take longer; as it so thick, damp it down occasionally with a water spray as it’s drying out to prevent cracking.

 

[reggie13]

Thanks Guys,

I had the first estimate come in the post today:

£800 for putting up scaffold up the staircase and hacking out all the old plaster (around 8 square metres)
disposing the debris
then putting up plasterboard.

He said it will take one long day or possibly 2 days work

I just rang the guy up and asked him use plaster and not plasterboard. He said he do it for the same price !

The gypsum website says that a 25kg bag will cover around 3 sq metres @ 11mm thickness. So that works out of 6 bags assuming two coats are required. B&Q do a bag for £6.64, I guess the trade price will be lower. Allowing an extra 25% for leveling out that works out to 8 bags. Then there's extra bag of finish plaster. So that comes up to max total for materials off around £60. Is this breakdown valid ?

Would you say £800 is reasonable price ?

 

[Richard C]

I had the first estimate come in the post today:
£800 for putting up scaffold up the staircase and hacking out all the old plaster (around 8 square metres)
disposing the debris
then putting up plasterboard.

Confused, I thought you said you were just repairing a hole & then having the wall re-skimmed?

He said it will take one long day or possibly 2 days work

8m of re-skim over a staircase would be OK in a day but if he’s removing all the old plaster, laying on a base coat & them skimming, I think it’s rather optimistic!

I just rang the guy up and asked him use plaster and not plasterboard. He said he do it for the same price !

I’m very surprised he’s offered to do it for the same price but £100/metre is high for re-skim, even if it is over stairs; nearer the mark if he’s removing old plaster, disposing of it, applying base coat & then skimming.

The gypsum website says that a 25kg bag will cover around 3 sq metres @ 11mm thickness. So that works out of 6 bags assuming two coats are required. B&Q do a bag for £6.64, I guess the trade price will be lower.
Allowing an extra 25% for leveling out that works out to 8 bags. Then there's extra bag of finish plaster. So that comes up to max total for materials off around £60. Is this breakdown valid ? Would you say £800 is reasonable price ?

B&Q trade centres are one of the cheapest around for cement & plaster products, I always get mine from there. £800 is a lot; £180 – £200/day is average for a good spread in the current climate but it can be higher depending on location. Add on the cost of the materials & there’s your price estimate! Always get more than 1 quote.

 

[reggie13]

Richard C, sorry if I wasn't clear; the whole section of the staircase wall needs to be hacked out and plastered back to the original level.

 

[Richard C]

OK no problem; but the rest is still relevant

 

[reggie13]

I has another estimate done, the guy come round and said that he would use sand-cement as the staircase wall is an exposed wall (ie the side wall of my semi detached house). Does it really matter if its exposed or not ? Surely it just like the front and back wall


Also, he asked me to strip off all the wallpaper before giving me an estimate.

 

[Richard C]

How old is the property, is the external wall a solid brick or cavity construction? Otherwise it shouldn’t make any difference but many plasterers will use render as a base coat, it’s cheaper & arguably better than a Gypsum plaster base coat; personally it would rather depend on how much of an area I had to cover.

If the job he’s quoting is to remove all existing plaster & apply a new base & finish, he's got to take it back to brick anyway so don’t really know the relevance of removing the wall paper. Perhaps he’s looking for cracks that may need additional reinforcing but he wont know how significant they are until he gets back to brick anyway, he obviously has his reasons.

 

[reggie13]

its a 1930's semi and the wall is solid brick. The outside of the wall has been pebble-dashed. There is a double glazed upvc window (1.4m high X 0.7m wide) in the middle top of the wall. I would not expect any dampness problem around the window or with the wall in general.

The total area to replace is around 8 sq metres at most. However, the 3 sq metres above the window sounds pretty sold when I tap it. So I might ask for that bit to left alone.

I started taking of the paper over the weekensd. I started at one corner,where the plaster is visibly blown. The plaster came clean off the brick as I pulled the paper down. The plaster was around 3/8 to 1/2 inch think at most.

reggie13