PVA cement board?

[Deleted member 307320]

Just a quick one, never skimmed cement board before!

Doesn't seem excessively absorbent, how will it be to skim when it's butted up to normal plasterboard?

Should I look at PVAing the lot to ensure consistency?

 

[23vc]

Cement board will probably be very low suction. Personally I wouldn’t bother pva’ing it but wouldn’t do any harm if you did. Mix it pretty strong to get it tacky

Edit: assume you’re taking about a shower ar

 

[lostinthelight]

I skimmed around the bathroom window reveals where I fitted Hardie backer and it sucked the life out if it and craze cracked full depth of the skim coat so think pva or sbr could be a wise move.
As above edit, i wouldn't skim if tiling .

 

[Wayners]

Yes. PVA.
No worries then.

As for cement board suction I don't know. I've used it to fill in areas where 9mn plasterboard was too thick and I sealed so I know plaster would stick no problem. Small areas I used halftime to speed plaster setting and never got any trouble skimming over cement board

 

[23vc]

I’m now getting deja vu to having skimmed over this stuff (assuming you’re talking aquapanel/hardybacker) and it crazing as @lostinthelight says above (even though I still think cement board should be low suction). So yeah, prep it if you must skim it, but if the whole thing’s designed right, there shouldn’t really be any of it that needs to be skimmed.

 

[noseall]

Cement board will probably be very low suction

 

[23vc]

I’ve given a fair few right answers over the years, I’ll allow myself one wrong one. As long as the OP didn’t knock the skim up before reading the whole thread we’re all good

 

[Notch7]

Why has the OP deleted his account

 

[23vc]

Why has the OP deleted his account

Oh crikey, it gets worse.

 

[noseall]

I’ve given a fair few right answers over the years, I’ll allow myself one wrong one. As long as the OP didn’t knock the skim up before reading the whole thread we’re all good

I thought the same as you, when I first fitted it. We now PVA then blu-grit it.