Hi, I've been reading around and asking questions elsewhere and I'm about to start preping my surfaces for tiling (tho haven't settled on the tiles yet), I'm just not certain about something.

Here is a list of the walls...

• Main wall has been plasterboarded completely with 12mm.
• A narrow wall, mix of sound plaster/render and plasterboard patched on (where the loose plaster was removed)
• Opposite main wall, lined with Hardibacker (will have the shower/bath against it)

I'm looking at using Mapei products, possibly Keraquick and also Mapegum (for my tanking), but when it comes to priming I want to make sure I don't bugger it so I asked Mapei about each of these walls.

Basically they told me:

1. Prime the plaster with 1:1 primer g + water
2. Backer boards need priming with 1:2 primer G + water but make it a thin coat
3. Don't prime the bare plasterboard

Does this seem correct?

Thing is I'm sure I've read somewhere on here that Hardi doesn't need priming if a cement based adhesive is being used ?

Perhaps I shouldn't question the manufacturer, but thought I should ask here just to be sure.

Thanks,
Stu.

Stu,

I'd guess they're bang on with their advice mate. Though manufacturers do sometimes over-engineer but it's not a bad thing.

Mapei are the world's largest manufacturer of building materials. What they say, pretty much goes.

Though I'll let the professional's on here give you more info mate, I don't tile any more myself to be honest.

Just wipe the hardi over with a damp sponge to remove surface dust.. the rest by Mapei is fine..

Thanks guys, much appreciated

Mapei advise 1:1 to 1:3 for primer G. I always use 1:3 I think it penetrates better thin, rather than sitting on the surface. Just my opinion

Thanks Phil, I'll go with 1:3 then, looking forward to doing this job. I'm only DIY but I enjoy it and like to (try to) do things better than the previous owners.

I'm down the M60 in Stockport so if I balls it up you'll be getting a call from me.