drying out time

[kilty55]

hi all again,,ive been using granfix flexible tubbed adhesive suitable for bathrooms etc on the bathroom walls ive just done,one tile which i fixed on 2 days ago came loose when pulling a spacer out which was stuck so i removed the tie and checked the adhesive which was stuck to the wall and it was still moist,,wasnt hard or dried out>? is this a normal amount of time for the adhesive not to have set properly also if im going to grout later on how long should i wait till its set so no moisture is stuck behind the tile?? i tiled directly onto plasterboard walls with no primer as advised is this correct? cheers

[Varley]

That is a long time, what size were the tiles that you fixed? If they were large format tiles (larger than 300mm X 300mm) then the air might not be able to penetrate deep enough to dry out adhesive behind the tile. Never used granfix tubbed gear before but they should state the drying time on the tub, seems a very long time not to have set enough to withstand you pulling a spacer out.

[whitebeam]

What tiles were they, I prime anything that is absorbent and use powdered ahesive 90% of the time nowadays

[kilty55]

thats what i thought?? 2 days and addy was still dampish,,only 2 tiles tho i cheked the rest of wall and all seemed fine..can u answer me this please,should you prime if tiling onto plasterboard with no skim on top? i was told you dont have to?

[Varley]

You sure do, the plasterboard can sap the moisture from the adhesive too quickly.

[ad tiling]

never used flexi tubb gear i have used granfix multifix and never had a problem,
if they are large tiles may take up to 7 days before you can grout
no primer needed.

[kilty55]

oh my god you are joking??? i never done it as advised by 2 tilers that new plaster yes i have to prime,but just boarded plaster i dont have to prime that,,what are the chances of this being disastrous??i did have 2 tiles come away when removing spacers after laying them 2 days ago but when i checked the adhesive it was damp enough to scarpe off??

[kilty55]

also this granfix tubbed addy was self primed surely that means i dont have to prime am i correct??

[Varley]

Never used granfix, but regardless of whether it says it has primer mixed in or not, I always prime anyway because it can't do any harm, that's just my opinion. At least if the fact that you didn't prime the plasterboard is the reason the tiles are coming off then ou should get the full backup of granfix if their adhesive states it has primer in it, What size were the tiles???

[kilty55]

hi they were 300mm by 100mm tiles,,not huge,the rest seem solid so far when the 1 came away all the adhesive was stuck to the wall nothing at all came away on the tile could this be because i maybe missed this tile and never pressed it into the adhesive correctly??

[Varley]

Yip that certainly sounds plausible, those tiles certainly are not too big for tubbed adhesive. More than likely you just haven't set the tile correctly as you stated.

[whitebeam]

It may well have been I always when fixing tiles move the tiles when bedding just so it works into the back of the tile.