Advice Needed?

[HardTarget]

It’s the original floor I think? They have done some sort of alteration to the kitchen side door entrance step in the past.

I have done a total refurb on the house and would love to keep the tiles, but she who must be obeyed wants new porcelain tiles she has seen at topps tiles. 🙄

The lads at work reckon I can just go over them using a flexible adhesive, but I’m worried about problems with movement or possibly damp and don’t mind going the extra if it helps, but so many ways and adhesives it’s confusing to say the least.

 

[Dave]

The black underneath could be a bitumen DPM.
As for the tiles , I'd personalall clean them to remove any old sealer and cleaning products that have built up over the yrs.

Then I'd fix the likes of Ditra over the floor , this prevents stress from the old floor transferring to the new floor and the old tiles will expand at a different rate and could cause issues.

But only you can decide if the old floor is suitable to tile over as we cannot see what you do.

 

[HardTarget]

I clocked that. I guess a lean-to come out-house attachment. Slabbed floor too.

Yeah spot on 🙂 It's a lean-to garage to the side of the house.

 

[Dan]

You need to be 100% sure they're fixed well so try get a few up. Doesn't matter if you make a mess if you're tiling it anyway.

I'd then soapy-water them. Dry them. Prime them. And tile them with a single-part flexible adhesive with no ditra. There's not going to be movement in those. They're very well settled I'd have thought.

Using a flexible adhesive means you'll take into account any lateral expansion and retraction differences in the two tiles. Which I'd assume wouldn't be much. Porcelain wont move much. And decades old quarries wouldn't either. Even fired at thousands of degrees quarries don't expand much.

 

[Dan]

Sorry was writing as Ditra Dave was writing then lol

He's got shares in that stuff I think. 😀 😀 😀

 

[Dan]

I'd seriously try and smash a few up with a SDS though in various places to really see how well they're fixed before tiling. I've seen streams under houses that old. And when the floor came up the substrate slowly washed away.

 

[HardTarget]

I've seen streams under houses that old. And when the floor came up the substrate slowly washed away.

Streams! 😱

I know from putting in the new water mains in with the plumber that the ground was rock hard clay down to 40" (main road to side of the house). The tile that came away when the plumber placed his pipes through I dug down through the black mortar and it was a light sand colour and quite easy to dig up. What adhesives/primers would you recommend? What about the bathroom Dan, would I be better with Ditra or similar or should I prime the ply and tile straight on top?

 

[Dan]

With so much cost at stake I'll let the professional wall and floor tilers recommend what they'd use.

I'm a mere web developer after all. ;-)

 

[Old Mod]

Streams! 😱

I know from putting in the new water mains in with the plumber that the ground was rock hard clay down to 40" (main road to side of the house). The tile that came away when the plumber placed his pipes through I dug down through the black mortar and it was a light sand colour and quite easy to dig up. What adhesives/primers would you recommend? What about the bathroom Dan, would I be better with Ditra or similar or should I prime the ply and tile straight on top?

Prime ply as per adhesive reccomendations and install Ditra and tile.
Any timber substrate is subject to deformation due to expansion and contraction due to temperature change and/or moisture.

 

[Dan]

The quarries, would you Ditra those @3_fall? like Dave would? Just for assurance?

And the "black stuff with soft brown stuff" - think that needs some samples taking? Rather than winging it?