Advice pls: Floor has already had PVA!!

[natalleyem]

Hi I'm looking for advice as to what to do next:
SITUATION:
Ensuite shower-room with shower tray.
Whole room to be tiled.
One wall leading into and inside of shower enclosure with Mosiacs.
Other wall inside shower enclosure large format tiles.
Rest of walls and floor large format tiles.
All tiles are metallic in design/colour.
Mosiac wall is mix of plastered plasterboard and bare ply - All joints/holes filled.
Floor is floor boarding sheets.
One wall plastered plasterboard
One wall (trowel finished) cement
Husband already started to PVA part of Mosiac wall onto plaster but I stopped him after reading this forum. The area he has PVA will not get wet but is to be tiled. He has also put PVA on the floorboarding sheets.
We are planning to use Unibond Ready Mixed Waterproof Wall Tile Adhesive -Extra Strong (Green/Yellow tub) and will probably purchase a similar ready mix floor tile adhesive product. Would rather use ready mix as DIY'ers.
We need to use a grey drying adhesive as any grouting product will be coloured dark grey.
Am now worried about PVA 'wet reaction' with Adhesive so Questions:
Should we/Do we need to rub PVA down?
What should we/do we need to prime/waterproof these surfaces with instead?
Have also applied PVA to concrete screed floor over underfloor heating which is soon to be tiled is this a big problem?
Your advice and suggestions would be very much appreciated before we go any further.
Thanking you in anticipation.

 

[mikethetile]

:welcome😱h dear😳

first of all take the tubs back and exchange for a mosaic adhesive

how neat was the pva. how much water was in it

 

[mikethetile]

and a cement based addy for your large format tiles

 

[mikethetile]

what are the floorboarding sheets

sorry about all the questions, but we need to get our heads around your bathroom, you will probably be answering questions all night

what tiles are the large format tiles

 

[natalleyem]

thanks for your advice Mikethetile - couple of further qu's if I may?

can you recommend a ready mixed mosiac adhesive that dries grey please?

and a cement based wall tile adhesive?

which adhesive do you recommend for for the floorboarding sheets?
and also for concrete screed floor?

would really prefer to use ready mix if possible!

thanks again
natalleyem

 

[natalleyem]

sorry we passed messages...

the floorboarding sheets seem to be a type of composite board

 

[natalleyem]

pva was 5 to 1 mix. Jewsons

Just one thin coat to only part of plastered wall.

2 x coats to floorboarding sheets

2 x coats to concrete screed floor (this floor is in another room)

 

[natalleyem]

mosiacs - mix of b & Q/casa ceramica metallic glass mosiacs
large format wall/floor tiles - marco polo dry pressed porcelain metallic finish
will check on tiles for concrete screed floor.

 

[mikethetile]

you really cant use tubbed for this job

its the way it dries thats the problem, tubbed dries by water dispersion into the substrate and the tile, the tiles you are using will not absorb enough to bond

you need a cement based addy as it dries by chemical reaction

have you already laid the backerboards to the floor

 

[natalleyem]

okay will avoid the tubbed - thanks

not using backerboards.

Builders have laid composite floorboarding sheets across expanse of bedroom including ensuite bathroom area. Am therefore assuming that it would be best to seal boarding to the bathroom area. Shower tray has already been fitted on top of boarding and waste is fixed in place. All ceilings below boxed in and plastered.