Primer. Im lost.

[geordie2013]

Starting a bathroom next week thanks for tips already recieved.
One thing still confusing me iv been advised to prime the floor and walls.

This probably sounds stupid but what is a primer. what does it do. how do you use it.

Sorry for asking a silly question but me mam always said if you dont know ask.

Cheers lads.

[Fekin]

Basically, a primer for walls is called Acrylic Primer and is only needed when the walls are plaster and or have been painted, and you need to use cement based powdered adhesive to fix your tiles, because the chemical compounds in cement based adhesives react against the chemical compounds in the plaster so that makes the adhesive not want to stick too well to the plastered walls.

This does not happen if you use tubbed ready mixed paste adhesive, as the chemical compounds in it are different and does not react like cement based adhesives.

Some people often prime the walls anyway even if yhey are not using cement based adhesive as it drys tacky giving you more stick so to speak.

Acrylic primer is just liquid, you paint it onto the plastered walls, and let it dry off, then you apply tile adhesive onto the walls as normal.

This is taken from Bal's website on Acrylic Primer APD

A modified acrylic polymer dispersion for use as a primer for a variety of backgrounds/bases prior to fixing ceramic tiles, mosaics and natural stone and prior to the application of levelling compound and the BAL WP1 TANKING SYSTEM. BAL PRIME APD isolates products containing calcium sulphate such as gypsum plaster and anhydrite screeds from cement-based adhesives, thus minimising the risk of reaction between the two materials.

Also suitable for use on cement:sand rendering, blockwork, plasterboard, cement:sand screeds and timber. It also provides surface strength to friable surfaces and reduces the porosity of porous backgrounds/bases, thus preventing the formation of air bubbles and prolonging the flow time with levelling compounds and extending the open time of tile adhesives. The primer is blue in colour to help ensure that a complete and even coating is obtained.

[GazTech]

Good advise Adam as per usual....Gaz

[Fred]

And , please don't fall for the ' pva will do' bit. pva isn't right for ANY tiling. As Fekin says, spot on.

[Fekin]

Yeah, PVA's worse than a dose of the clap

[geordie2013]

Why whats wrong with pva. Got to tile a bathroom floor monday ply on floor. Customer has bottle of pva. cheers

[Dave]

hi ..read this and will explain all about p.v.a...........dave..

http://www.tilersforums.co.uk/tiling...s-primers.html

[versatilene]

P.V.A. has no place in a tilers van, If you haven't got any your'e not tempted.

[devonmark]

Originally Posted by versatilene

P.V.A. has no place in a tilers van, If you haven't got any your'e not tempted.

well said that man..

geordie, use pva on a job, say new plaster ,go back to it in 6 months and see if you can get the tiles off the wall? they will come off as though they have never had any adheshive on their back, acrylic is more expensive but if the tiles fall off after 6 months and the job has to be re-done then how cheap will the acrylic primer look then???

roughen up polished plaster before priming. Its possibly a little OTT but i remove the polished surface completely with coarse paper ( by hand) dust down and then prime. Tiles should NEVER fall off

[Matty A]

So whats the difference between Acrylic primer and SBR cos it says on the back of the bottle of sbr that i have that it can be used as primer prior to tiling installations.

Also the bottle i have is a 5ltr everbuild and cost £11.99 plus vat which is much cheaper than your bal stuff and if you charge the customer half that i dont think you will use half a bottle on one job. Plus if its cheap it doesnt seem such a waste to prime the under sides of ply when overboarding flors prior to tiling.

Mat