Priming Insulation Boards

[Flintstone]

who usually primes the back of a cement coated board? I have some times and not others

 

[jobdone]

I know some manufacturers say it is not necessary bit I always prime first.

 

[Sean Kelly]

Just wipe them down with a damp sponge/cloth.

 

[radim]

I hoover them but dont prime. But interested wot others recomend...

 

[kevsalt]

yeah always do with acrylic...stops em sucking all the life out of your addy

 

[Flintstone]

They won't suck the life out as there is only a very small skim or cement on them and then it's foam

 

[kevsalt]

sorry read it wrong thought you ment no more ply

 

[MW Smith Ceramics]

Ye

sorry read it wrong thought you ment no more ply

yeah I thought the same

 

[Stef]

I prime before I tile but I don't prime the backs of the boards.
It's only recommended to prime the back & sides of a ply wood overlay.

 

[White Room]

Never primed a cement coated board as in wedi, marmox etc...

 

[MW Smith Ceramics]

I always prime Hardi & no more ply but just run over cement boards with a very damp sponge before fixing onto them....

 

[Stef]

I always prime Hardi & no more ply but just run over cement boards with a very damp sponge before fixing onto them....

Hardie is a cement board.
They state you only need to wipe over boards with a damp sponge but I prime them as there isn't going to be an adverse reaction to doing it..
Almost everything I tile gets primed.

 

[hmtiling]

I prime insulation boards so the ufh sticks to them better

 

[Doggit]

is that xps boards as well, and if so (as I'm about to lay some) what ratio primer to water please

 

[LM]

is that xps boards as well, and if so (as I'm about to lay some) what ratio primer to water please

It depends on the make of primer, they all have different densities. It'll tell you in the data sheet. Treat it like your priming a skimmed wall, first coat well diluted 2 or 3-1 to allow it to soak in and second coat 2-1 or neat, it depends on the primer