Old adhesive, bitumen??

[Bartlett]

You can Tile on top but you would need an epoxy primer, i know weber and PCI do one.

Aha, that's interesting. I spoke to Mapei earlier to double-check and they confirmed that all bitumen should be removed 'as it can get warm and therefore become flexible.' So how does the epoxy primer deal with that?

 

[DHTiling]

If the old adhesive is well and truly stuck , then you can slurry coat over it...for increased adhesion.

 

[Bartlett]

If the old adhesive is well and truly stuck , then you can slurry coat over it...for increased adhesion.

Sorry Dave, pardon my ignorance. I think I know what you mean but can you define 'slurry coat' for me?

 

[Gazzer]

Slurry coat is a mix of adhesive and water mixed thinly.

 

[DHTiling]

Slurry coat is portland cement mixed with SBR....or rapid set will suffice...but needs to be SBR...this helps with the adhesion of the slurry coat to difficult substrates...and tile on tile if needed.

 

[Bartlett]

If the old adhesive is well and truly stuck , then you can slurry coat over it...for increased adhesion.

So despite the advice to the contrary from Mapei this really would be okay? ie, leave the adhesive in place (it is a very thin layer and seems firm) then slurry coat over it and then tile as normal? Sounds good to me.

 

[Gazzer]

So despite the advice to the contrary from Mapei this really would be okay? ie, leave the adhesive in place (it is a very thin layer and seems firm) then slurry coat over it and then tile as normal? Sounds good to me.

Its worked for me for the last 32 years

 

[Bartlett]

Its worked for me for the last 32 years

Haha, sounds good to me. So drawing on the benefit of your experience what mix should the slurry coat be? Or are we simply talking very thin and runny? Do you use cement or tile adhesive? I was planning to use Keraflex to do the floor tiling.

 

[DHTiling]

So despite the advice to the contrary from Mapei this really would be okay? ie, leave the adhesive in place (it is a very thin layer and seems firm) then slurry coat over it and then tile as normal? Sounds good to me.

No disrespect to mapei, but they would have been advising you for only using tile adhesive and not using a slurry coat first.

Different method to just using adhesive over it....and yes it works well does a slurry coat.

 

[Bartlett]

Okay, final question (or maybe not?), just want to make sure I do this right!
Slurry coat and tile immediately after, or let it dry overnight?