Confused Lafarge do not reccomend skimming

[paulsa]

Having read the forums receiving some useful replies (thanks Richard C et al) and the obvious preference for skimming over plasterboard and moistureboard (after priming with ThistleBond-it ) I thought I would ask the manufacturers their recommended plaster for skimming on Lafarge boards. I received this :-


"......
Dear Sir

I confirm that no pre treatment is required before tiling moisture board.

In respect of the skimming, we do not recommend a skim finish on moisture board. There is no point using a moisture resistant product and covering it over with a non moisture finish. Also the skim does not adhere to the surface very well and there is a chance it will 'shell off'. However if you still decide to skim you will need to pva the board twice and skim on the second coat whilst still tacky.

Regards

Lafarge Plasterboard Ltd

.........."

I found this odd as I was under the impression that skimming was actually the standard finish for plasterboard including moisture board. Plus as is clear from the forum PVA is not the best for priming MR P/b.

Should I let this influence me or is this not strictly true?

Regards

Paul

 

[PrenticeBoyofDerry]

MR boards are not a suitable base for a plaster finish, I have said this before and will say it again!
MR boards are for tiling or undecorated finishes, you can joint tape them though, but as proved by applying bond it as a surface primer you will get away with a plaster skim, but the manufacturers will not sanction this.

 

[1john]

I think alot of us have stated before what the manufacturer has confirmed, there is no point in applying a non-moisture resistant product over the top of a moisture resistant material, it defeats the object.

 

[STEVESB]

Lafarge is a french company and over here they prefer tape and join so that may be why they recomend not skiming the normal plasterboard. the others are right in stating that there is no need to skim MR board.
I have skimmed MR board when a client used a sheet when he ran out of normal to finnish a room off and found no difference in the application of the paster

 

[paulsa]

Many thanks for the replies I could see their point but thought it best to ask people who have experience.

Sorry it may have been an old question but it wasn't to me. I did check the forums but there is a lot on here.

Thanks again guys.

 

[Richard C]

MR board is not primarily intended for skimming but if you use it in bath/shower/kitchens (which you should) & want a plaster finish to part or all of the wall then you have no choice; it’s far better than just painting over un-plastered board or skimming standard Wall Board.

BG give specific advise for skimming over MR board & there is absolutely no problem with it providing you use a bonding primer/agent first; either Thistle Bond-It or you could probably make your own with PVA & a plaster powder mix. I would not follow Lafarge advice for skimming over wet PVA which could give you all sorts of problems, as stated they are a French company who favour tape & fill; use decent English company products & follow their advice – British Gypsum every time.

 

[Micilin]

Good advice all round - why add skim in a wet area ?

Always go by the spec if you want no comebacks.

But in practice I can honestly say I have seen loads of MR skimmed with no prep and no problems.

If anyone has a spare off cut, skim it and try to get the plaster off after six months - I defy you !

 

[Richard C]

why add skim in a wet area ?

Spot on, it’s completely unnecessary; it will seriously restrict tile weight & cause all sorts of problems; use waterproof tile backer board, it’s what it’s designed for.

But in practice I can honestly say I have seen loads of MR skimmed with no prep and no problems. If anyone has a spare off cut, skim it and try to get the plaster off after six months - I defy you!

I always check specs on anything I do as they are generally (but not always) there for good reason; where it's been necessary to skim it, I’ve always primed MR & never had any problems. I’m positive that loads of it gets skimmed “straight off” purely out of ignorance but I have to admit I've never skimmed it bare.