seal rendered wall before tile ?

[Alan Knight]

hi everyone, long time lurker but first post here

Building some new toilets at work so the old one can be knocked down, new room is 1.2m wide x 5m long, the door is in the middle of the 5m wall.



(dorway is going to be trimmed with stainless steel)

(toilet at each end, doors 200mm above floor, open top, knee operated sink in the middle)

I planned to go with smooth concrete rendered walls, the idea being we can steam clean in there when we do the rest of the factory - have seen the same thing working well elsewhere - there's a bit here my grandfather did in the 60's and it's still good as new

customer who is a brickie made a nice job of a couple of walls... and said he worked as a plasterer for years, he could do the render no problem... great I thought

but the render is pretty crap, I've done a couple of little non important bits myself before and mine was better than this, it's rough/dusty, rubs off by hand, not that flat etc. etc.

so the new plan is to tile the walls, I'm thinking I should seal the walls before I tial them - any pointers on which product to use?

when I tile them, I'll need them stuck on tight to wall and good grout to stand up to the steam cleaner - any recommendations for products to use there?

I'm thinking 200x200 tiles will be best with the walls not being that flat?


thanks in advance for any ideas/replies

Alan 🙂

 

[WetSaw]

If the render rubs off with your hand I'd say it needs to come off. You say factory and steam cleaning, what sort of factory?

 

[White Room]

If the render is solid then tile straight on but as mentioned above if powderer then you may need to stabilise and hopefully he didn't use soft sand to render.

 

[Alan Knight]

it's a dog food factory

maybe saying the render rubs off comes across too strong.. you run your hand across it and you make dust - you can kick it with a steel capped boot and it's not loose, non comes off, it's well stuck to the wall

sand is proper rendering sand, I organised that myself

I was thinking decent waterproof PVA on the wall first, then tile on top of that

when looking for adhesive I saw some "Bostik Super-Grip" stuff, thought that might be better stuff to use? no idea how different it is, and if it's any different long term or if it just grabs better at first when you put the tile on?