Priming Question

[cosmarchy]

Hi,

BAL advise priming the underside of chipboard with SBR before tiling. Is this necessary if the chipboard is the green moisture resistant type?

And why prime the underside anyway?

Thanks

 

[tpt]

i'd be surprised if they have intentionally advised to use chip - ply would be the usual reccomendation, but either way the reason is to try to prevent moisture ingress from the back

take it from me - stay away from chip - especially the new green stuff. nothing sticks to it well, use ply or overboard it with no more ply type backerboard

 

[Richard C]

Good advise from TPT; dump the chipboard it's crap & probably the worst possible tile base you could find. Get some WBP ply, 18-25mm actual thickness you will need depends on the floor joist size/pitch/span.

& yes acyrlic prime the underside & edges.