PVA and why you shouldn't use it as a tiling primer.

[jbonding]

thats why i say mix with cement and sand and this has the same effect a sbr it stops the pva coming alive, its been done for years before they put it in a fancy tub and renamed it. applying with a roller and the sand will provide the key.

Actually if you take a look at the post you made on the rendering thread where you cut and pasted the PVA breakdown of / uses from that university type, you'll find that SBR is a polymer modified version of PVA, in so much as it has other chemicals in it.

Adding sand and or cement to PVA isn't doing the same thing. The fact remains that PVA isn't compatible with tile adhesives full stop, you seem to be struggling to grasp this idea.

i agree there are other chemicals added and its not the same but has the same effect. Out of interest and i presume you know your **** by reading your posts, what did they use years ago.

 

[Mudster]

If by years ago you mean before all these carlos fandango adhesives and primers were developed, they didn't use any of it.

It was sand/cement render atteched directly to a scratch coated wall. Now this really works, you'll know if you ever tried to strip out any 30's house.

 

[jbonding]

If by years ago you mean before all these carlos fandango adhesives and primers were developed, they didn't use any of it.

It was sand/cement render atteched directly to a scratch coated wall. Now this really works, you'll know if you ever tried to strip out any 30's house.

oh i know ive tried to shift it, its like trying too split steel with a bolster but with tiny blades flying all over the place, no i mean well after the 30s lets say from the 70s onwards.

 

[Mudster]

normally ready mixed rubbish which had a finite life, I've no idea if people use a PVA coat before hand, but by the way many of these strip off I wouldn't be surprised if they had.

The rooms you walk into that have 4 inch Crystal tiles that you can strip with a wallpaper scraper are the ones.

I've been tiling for about 15 years and during all that time there have been specific products for prinming, although these have evolved in my working lfe time.

 

[jbonding]

normally ready mixed rubbish which had a finite life, I've no idea if people use a PVA coat before hand, but by the way many of these strip off I wouldn't be surprised if they had.

The rooms you walk into that have 4 inch Crystal tiles that you can strip with a wallpaper scraper are the ones.

I've been tiling for about 15 years and during all that time there have been specific products for prinming, although these have evolved in my working lfe time.

it makes you wonder how they evolve when you think back to ten years ago some products were spouting theirs was the best ever and there still doing it now, but there better than ever, the number of times fairy liquid has got better is unbelievable, imagine next year it will be better. i think most of these products are based around pva (not fairy liquid) and it would be interesting to know if the main ingredients were pva.

 

[Horse Hair]

Hi

I have been following the thread on the use of PVA as a primer before wall tiling.
I would like to ask Mudster a question.
Can you use another manufacturers ready mix adhesive after priming with BAL-APD or must you use BAL adhesives.
Not worried about guarantees etc.

Good thread by the way.
Horse Hair

 

[Mudster]

Technically I don't know, I'm not a chemist so can not give a difinitive answer to that.

My opinion, it's probably ok, I just tend to stick with whatever the manufacturer specifies so I have a guarantee.

Many of the ready mixed adhesives claim to be self priming, I'm also no expert on these as I can't use them in the line of work I'm in, they don't have enough mecahanical grip to support natural stone tiles.

 

[braychurchmouse]

Sorry to rejuvinate an old thread, but came on this by accident...and just in time .
I have just "primed" an area prior to tiling with diluted PVA...probably about 5 to 1. Some of the area is bare plaster and some has a coat or two of emulsion. I guess the best thing for me to do is thoroughly scour the surface and reprime with one of the products mentioned in the thread?

Fortunately its only about 3 square metres. Seems a pity I've got to buy a whole new pot of Ardex or whatever...do I really need this primer or could I just tile onto the plaster? Maybe a coat of diluted contract emulsion to reduce the absorption??? What do you experts recommend?

 

[Mudster]

The paint needs to be removed and a correct primer used.

 

[byron]

I am about to have my kitchen floor tiled by a tiler,if the tiler wants to prime the floor with pva should I tell him about Mudsters theory.I do not want to appear to be telling him his job.The floor at present is tiled with the old type six inch square red tiles that are about one inch thick perhaps they will not need priming?

 

[gcol]

I wouldn't pva a floor, especially over existing tiles. Just make sure that they are cleaned/degreased before he tiles them. It should be he that cleans them really - so he will know that it's been done right.
Cheers,
Gcol

 

[byron]

thanks for the reply gcol

 

[Darran]

Mudster (& everyone)

I have just stumbled across this very useful forum thread. We've just had our bathroom re-plastered. We're tiling the shower area. Plasterer said to wait a couple of weeks, then PVA, then put tiles up. I've bought BAL Grip water-resistant adhesive, and therefore following your advice will not use PVA. The directions on the tub of adhesive make no mention of using BAL primer, and the tile shop I bought it from say to apply adhesive straight onto the dried plaster. Does this sound okay to you, ie using no primer at all?
Also, does 2 weeks drying time sound a bit short...it's only 6mm ceramic tiles we're putting up?

 

[Plumbfit]

mix more water with less p.v.a. if there is too much p.v.a. in the mix it will form a layer on the wall and the adhesive sticks to this layer, rather than the wall surface

 

[gaz2923]

ive just tiled my bathroom without priming the plasterboard/paint that was already there

plaster was bare where paint had come off with wallpaper, will my tiles fall off?