Mapei primer

**CUSH68** · 13-09-2008

Hi All,

Just started using the mapei range and have a job next week with large format tiles onto green plasterboard but struggling to get an exact dilution ratio with regards to the primer required for this.
Have downloaded the specs for mapeis primer "g" but only covers gypsum plaster (neat coat), nothing really for plasterboard.

Any info on this would be appreciated.

Mark

**Alberta Stone** · 13-09-2008

I use ultraprime L and for porous surfaces they say 3 parts water to 1 part primer for the first coat and the second coat is 1 to 1.

**pjc** · 13-09-2008

i am not a mapei man but most cement based adhesives you don't need to prime but it is better with the ordinary plaster board you will be better using SPF as it doesn't key as well to the green plaster board :Pete