Heavy Porcelain tiles????

[Gazebo]

I shall be refitting 2 shower enclosures for a customer and in both the customer has chosen (but not yet purchased) 600x300 porcelain wall tiles.

My problem is that the existing internal walls are 4inch block with some form of undercoat plaster (probably bonding) then plaster skim.

Having removed the tiling in 1 enclosure some of ther skim coat has stayed put some has come away.

I am aware of the weight limits. ie. skim 20kg per sqm, board 32kg per sqm, marmox 60odd kg per sqm.

How do I go about prepping these solid walls to take these tiles.???

Can reline the existing walls with backer board with a bed of adhesive then plug and screw it, or is the only way to do it by hacking bonding off back to blockwork then dot n dabbing board.???

Cheers
Gary

[david campbell]

you can use the backer board as long as the fixings are going into the blockwork and not just the plaster coat,either that it's the time consuming way of removing the plaster

[Gazebo]

Thanks David,

Could I use 6mm Hardibacker and a notched trowel (what size)to spread spf to the existing walls, then as you say drive in some plugs n screws long enough to grab into the blockwork.

Or would you use a 12mm board either hardibacker or maybe go for marmox 10mm.???

Thanks

[david campbell]

i would use the marmox boarbs because it's a shower enclosure,it depends on how bad the walls are for what trowel yoiu are using probably a min 10mm

[Gazebo]

Thanks David,

If I am to use this method with the marmox board fixed with appropriate fixing washers etc.
What prep would you advise if the walls are
1.painted skim coat over
2.skim coat
3.patchy skim coat over bonding coat where old tiles have been removed.


Thanks again

Gary