skim behind kitchen units/splashback?

[mazears]

I'm in the process of dot dabbin kitchen walls. I've used standard grey 12.5mm plasterboard.

1.Can i continue to use standard plasterboard for the whole kitchen even behind where the sink/washing machine will be or is moisture resistant more advisable in this area? - window cill above sink may also be tiled...

2.The splash back between wall/base units will eventually be tiled. Do i refrain from skimming these areas as i've been told tiles will stick better to bare plasterboard?

3.Also, is it necessary to skim behind base units as this will not be seen?

Just unsure as to whether i should skim the whole of this side of the kitchen where wall/base units are going + tiles for splashback area!

4.Lastly, is it ok to skim kitchen walls 1st and at a later date attach plasterboard to ceiling joists and skim that secondly,as opposed to doing both at same time? (need to leave ceiling off at present as havent sorted plumbing for upstairs bathroom) Just wondering about the joint tape scenario and whether it'll be able to blend in from already plastered walls to ceiling...

 

[tommyl18]

hi the ceiling will need to be boarded 1st as you will never get the tape to match up on a previously skimmed wall, you can just skim donw to where you want behind the base units just make sure you leave it flat so the units fit the wall, you can use standard plasterboard behind washing machine as long as its plastered this area shouldnt get wet if it does there is something wrong, and the wall behind the sink should be ok with standard board make sure its plasterered as this area will be tiled and if sealed properly water should never get to the boards

 

[mazears]

Thanks tommy. I decided to board behind washing machine/sink with moisture resistant board-maybe i should skim this area also for extra protection. Still wondering about splashback area between base units and wall units. If these are eventually being tiled should i refrain from skimming this part? Think you're right about ceiling having to be taped/skimmed as one with walls-was just hoping i could do ceiling seperately at a later date!

 

[2929twin]

I was always taught to skim wall before tiling, cant remember why.

 

[tommyl18]

yea i do to be honest but i was talking to a tiler the other day who phone up british gypsum and they stated that multi finish or board finish is not suitable for being tiled onto as its not strong enough to support the tiles especially bigger tiles although ive never had any problems personnally

 

[Richard C]

Unplastered boards will take 32kg/sqm; skimmed boards reduces the weight to 20kg/sqm (including adhesive & grout) so it really depends on the tiles your using but even at 20kg/sqm, they are going to be pretty heavy tiles.

A skim over boards will help keep moisture out to a certain extent but in wet areas you should really be using waterproof tile backer boards or tanking. Moisture Resistant boards are OK for a kitchen but if you want to skim, you must apply a bonding primer first or the plaster won’t adhere at all well.

 

[mazears]

Richard. I've used normal plasterboard on all kitchen except one full sheet of MR board (horizontal) behind the washing machine/sink. Are you saying this one board requires bonding (Thistlebond-it?) before skimming. Seems an expensive 10l tub just for this one board or does the other normal plasterboard also need bonding before skimming?

 

[Richard C]

MR board & the external paper linings are impregnated with a water repellent additive so need a bonding primer or the plaster won’t stick.

No priming is required for standard wall board, not even PVA.

 

[mazears]

Is there a bonding primer i can use other than thistlebond-it as i don't what to buy 10l tub as i only need a small amount to cover this one board-can i use sbr bonding as i already have some of this?