Tiling onto plaster on terricotta brick wall

[jwatson]

Hi just looking for some advice. Do the normal weight regs still apply on plastered wall if the substrate underneath is terricotta brick or would itit be reduced. They don't seem very strong

 

[Robb o]

Are you talking about Porotherm or sometimes called 'spanish block'?
If you are I would say that these walls are installed on a 1 mm bed of mortar along the horizontal perp and they lock together,with no mortar between the vertical perp.
You are right they are not the strongest and I have seen alot of movement if they are only a single block width.
Has insulation (celotex) been fixed to the wall before plasterboard? as this will also make a difference on your tile weight.

 

[DHTiling]

The weight is the skim coat... so will apply.