Warped backer board | warped no more ply after priming!

[SteUK]

Evening all, me again!

Just primed (3 to 1 sbr) one side of a sheet of my backer board in preparation for putting some up tomorrow and it has warped! I can press it flat to the wall but it has me concerned. How much warp is too much? Is this normal?

Thanks!

 

[Dave]

What backer board ?

 

[SteUK]

6mm No more ply (for my uneducated sins)

 

[Dave]

Soooo, why did you prime it ?

 

[Dave]

Just checked NMP website , for complete waterproofing prime with SBR 3:1 lol lol.... Nah!!!!!!!



As for your question , the screws will flatten it out .

 

[SteUK]

Hehe. Yeah. They say prime both sides with 3 to 1 mix of sbr.

Even with my diy knowledge I laughed when I read that. Don't worry, I have a mapei tanking kit for around the bath (and over shower) area

It's probably only warped 5mm on the short end and 10mm on the long edge. I was going to put it up with adhesive then screw down when set. Guess I will have to kind of level it out with screws before the adhesive sets. But be careful not to go mad with the driver!

 

[judge]

Hi ste,Im pretty sure 6 mm is flooring grade.(never used it ) with hardi its 6 for floors and 12 on the walls

 

[SteUK]

Hi judge,

Thanks for the input!

Manufacturers say their 6mm is fine for walls. Though they say dot and dab is how to fix to solid walls, which I cannot get on board with...so putting down a full bed of adhesive and mechanically fixing as per instruction as well.

 

[Rizzle from the Portizzle]

so this board does not like water on one side only reminds me of a sponge .the water resistant a great get out always read the small print if you go to b&q you will find water proof bucket adhesive read the small print water resistant .shame on mapie so when do they put the truth in big letters

 

[White Room]

so this board does not like water on one side only reminds me of a sponge .the water resistant a great get out always read the small print if you go to b&q you will find water proof bucket adhesive read the small print water resistant .shame on mapie so when do they put the truth in big letters

Your'd then read it Ray.....