skim coat on green plasterboard for bathrooms

bertie 56

Hi everybody , plasterboard specialists and others...

I have a simple question here :what type of finishing plaster is needed for a skim-coat in a bathroom , over green boards ?
Is it the same plaster as in other rooms, or is it a special " moisture resistant " one ?

I've noted that a primer is necessary and that it's possible to find some moisture resistant filler for the joints , but no sign of moisture resistant plaster for a skim coat .

Any recommendations ?

Thanks in advance

Bertie

kkelliher

bertie 56 wrote: »

Hi everybody , plasterboard specialists and others...

I have a simple question here :what type of finishing plaster is needed for a skim-coat in a bathroom , over green boards ?
Is it the same plaster as in other rooms, or is it a special " moisture resistant " one ?

I've noted that a primer is necessary and that it's possible to find some moisture resistant filler for the joints , but no sign of moisture resistant plaster for a skim coat .

Any recommendations ?

Thanks in advance

Bertie

Its the same skim plaster everywhere if required. I have always queried if you need to skim in areas of tiling and I have always received differing opinions

D_D

kkelliher wrote: »

Its the same skim plaster everywhere if required. I have always queried if you need to skim in areas of tiling and I have always received differing opinions

I was told that 'it is a better job' if the skim is applied to the plasterboard beforehand. It limits the damage when you're taking off the tile in the future, as the adhesive is applied to the plaster and not directly to the board. The adhesive can go rock hard and is a nightmare to get off once it is in constant contact with water.

sky6

Make sure to do any Tiling before you do any painting. I've seen people paint as soon as possible in order to clean the room up. Only to find that they have a problem when it comes to Tiling. You then have to try and clean the paint back off in order to ensure good adhesion for the Tiles.

whupdedo

D_D wrote: »

I was told that 'it is a better job' if the skim is applied to the plasterboard beforehand. It limits the damage when you're taking off the tile in the future, as the adhesive is applied to the plaster and not directly to the board. The adhesive can go rock hard and is a nightmare to get off once it is in constant contact with water.

This is wrong, firstly why would you do a job to make it easier to take off in the future, the whole idea is that it's supposed to stay for as long as possible, I've seen tiles lift off because they were applied onto skim

And secondly the adhesive is supposed to go rock hard, that's the whole idea, if water gets in between the tile and skim it will lift off, sometimes it won't do if applied straight to the slab

bertie 56

Thanks everybody for sharing your experience.

What about the joint filler for taping before the skim coat ? I saw that Gyproc has some " green " joint filler , for green plasterboard.
It seems hard to find this type in shops, though. Is it commonly used ?
My concern is to cover the few butted seams I have . Would it be better to use some moisture resistant filler instead the normal one ?

Any recommandations ?

Thanks.

bertie 56

.

whupdedo

Are you going to tile over the green slab ?

bertie 56

whupdedo wrote: »

Are you going to tile over the green slab ?

Yes, partially, a good bit around the sink and outside the shower . That is roughly 20% of the walls.

No tiles in ceiling though

no1murray

I would use 1/2 inch wpb plywood for the areas that will be tiled. Green board with skim everywhere else. I would also use a tanking material in the show area.

whupdedo

bertie 56 wrote: »

Yes, partially, a good bit around the sink and outside the shower . That is roughly 20% of the walls.

No tiles in ceiling though

You'll be fine using green board everywhere, just don't skim the areas that will be tiled, and don't use plywood anywhere, no matter what anyone tells you, and it doesn't matter whether it's marine ply or not it is not suitable to be tiled on, the tile will get plenty adhesion to the green board

cerastes

I followed the thread so I could see what recommendations were made,
curious as to whats being said,
Id never had green board in my house, at least I dont believe so, when I moved in, the walls already had been painted with a base coat and I presume skimmed before that.
I tiled over it and what went up has been in place ever since. Ive heard of green board since but only recently, but with differing opinions on whether to prime, skim or none of that at all.
Is tanking done with some kind of flexible sheeted material or applied as a paint like substance? is it recommended or now a better option.
Are there different categories of it? depending on just tanking the sides of a shower with a tray or if used in a wetroom. Id consider a drain in the floor connected into an existing drain for spills/cleaning, although I dont think Id be keen on a shower room set up. Either way is tanking a better option for an entire room anyway to contain any moisture as Ive read tile adhesive is only water resistant and not water proof.

curious as to the condition under my tiles now.

bertie 56

Thanks for your advices.
Yes, tanking in the shower is planned.
I won't use ply, the quality of so-called " WBP " is not really impressive...
So, yes, green boards everywhere ( except shower ), but what stuff to use for jointing and taping, ( prior skimming) that is the question ?
Basic joint filler , like in other rooms , or green joint filler ( which seems hard to find, by the way ) ?

cerastes

bertie 56 wrote: »

Thanks for your advices.
Yes, tanking in the shower is planned.
I won't use ply, the quality of so-called " WBP " is not really impressive...
So, yes, green boards everywhere ( except shower ), but what stuff to use for jointing and taping, ( prior skimming) that is the question ?
Basic joint filler , like in other rooms , or green joint filler ( which seems hard to find, by the way ) ?

I thought the green boards were for wet areas? showers, baths?
I'll be interested in the replies to this post, but wasnt skimming advised against? what about priming the surface of the green board?

mfceiling

Green board is specific for high moisture areas ie showers.

The boards don't need skimmed however where you intend on painting you should fill and sand the joints where the boards butt together to leave an even surface.

The latest board that we are seeing more of is "gtec aquacheck"

http://www.siniat.co.uk/products/gtec-board/gtec-aqua-board/

BryanF

mfceiling wrote: »

Green board is specific for high moisture areas ie showers.

The boards don't need skimmed however where you intend on painting you should fill and sand the joints where the boards butt together to leave an even surface.

The latest board that we are seeing more of is "gtec aquacheck"

http://www.siniat.co.uk/products/gtec-board/gtec-aqua-board/

MF is this stuff just cheaper than fermacell or gyproc placocem et al ?

mfceiling

BryanF wrote: »

MF is this stuff just cheaper than fermacell or gyproc placocem et al ?

I think it's cheaper than Fermacell Brian..we are not supplying, the main contractor is. Fermacell is very expensive and to install it properly is a pain!! All joints need special glue and the proper screws must be used - even cutting it is a skilsaw job. Not to mention the bloody weight of it!!

The aquatec board can be cut with a stanley knife and screwed with regular drywall screws. Seems to be popular enough nowadays.

bertie 56

cerastes wrote: »

I thought the green boards were for wet areas? showers, baths?


According to some people that have a better knowledge than me on the subject , a better alternative to green board in a shower enclosure would be cement board.

fozz10

wow, 18 posts in and no one mentioned you should NEVER skim directly over green slabs. if you are then you must thistlebond all slabs first. I hope none are ye are plasterers. moisture resistant.... hence the skim will not stick properly and can be pushed off over time.

bertie 56

fozz10 wrote: »

wow, 18 posts in and no one mentioned you should NEVER skim directly over green slabs. if you are then you must thistlebond all slabs first. I hope none are ye are plasterers. moisture resistant.... hence the skim will not stick properly and can be pushed off over time.

Thanks for your input, Fozz10, but as said in my first post :
" I've noted that a primer is necessary" .
( with the product you named, by the way )

fozz10

bertie 56 wrote: »

Thanks for your input, Fozz10, but as said in my first post :
" I've noted that a primer is necessary" .
( with the product you named, by the way )

Ah sorry!