Diluting primer before tiling - Tile Advice

[SP87]

Am getting conflicting answers online and manufacturer support lines, have a bathroom which has Hardiebacker, moisture plasterboard and multi finish on different walls and is being fully tiled.

Can anyone advise correct dilution ratios for priming these walls with Mapei Primer G? Will be using Mapei S1 powdered adhesive.

Mapei support said no primer needed if using Mapei adhesive, but to apply 1:1 diluted ratio if I want to.

Hardiebacker support said their boards do need priming, although their website says they can be tiled onto without primer...

Am I correct in thinking the more dilution (ie. If I did 1 part primer to 2 parts water on all surfaces), the less likely a skin would be formed and less likely adhesive will fail in long term?

 

[Dave]

Wipe any dust off with a damp sponge. No primer required on the boards. The multi finish will require priming .

 

[SP87]

Wipe any dust off with a damp sponge. No primer required on the boards. The multi finish will require priming .

OK will just prime the multi finish, not the hardiebacker and moisture resistant plasterboard.

Hardiebacker boards are in the shower wet area, is tanking them necessary before tiling?

 

[SP87]

Also what ratio should I dilute the multi finish with Mapei Primer g before tiling?

Many thanks

Wipe any dust off with a damp sponge. No primer required on the boards. The multi finish will require priming .

 

[Dave]

OK will just prime the multi finish, not the hardiebacker and moisture resistant plasterboard.

Hardiebacker boards are in the shower wet area, is tanking them necessary before tiling?

Tape the joints, that suffice for a domestic shower.

 

[Dave]

Also what ratio should I dilute the multi finish with Mapei Primer g before tiling?

Many thanks

Is it primer G. ?

 

[SP87]

Is it primer G. ?

Yes Mapei Primer G

 

[Dave]

Yes Mapei Primer G

3:1 will be fine x 2 coats