My builder says epoxy grout too "inflexible"?! - TilersForums.com

[Tardigrade]

Hello,

I'm tiling my bathroom. Rectangular tiles, brick pattern. Most are new stud walls with plasterboard. Floor to ceiling, but not floor itself, and quite a few corners / niches etc.

I specified epoxy grout at onset (because: mumsnet ) so cost isn't an issue (for me). I liked the rave reviews of never having to seal or clean / no mould etc.

On reminding him of the need to use epoxy grout he said:
1) I want to use Mapei ultracolour plus (which he referred to as normal grout)
2) Epoxy grout isn't "flexible" enough and as plasterboard/stud walls flex over time, I should expect tiles to crack if he goes ahead and uses it.

a) is this even normal grout? Looks a bit different going by the marketing blurb
b) is there any truth to epoxy's "inflexibility"?
c) is this because he isn't following best practice and should eg have something else supporting the plasterboard?
d) I've come across some grouts that appear to be a bit of a hybrid eg mapei flexcolour CQ - is there anything to this middle ground?

I'm a bit worried about forcing a reluctant tradesman to do something he is less familiar with in case the quality suffers, and certainly don't want to be storing up problems but I want the quality outcome I paid for...thoughts?

Thank you!

 

[macten]

Epoxy grout is less flexible than a modified grout like UC+ but will be fine to use in your situation. Just be sure to use silicone at movement joints like you normally would.

It is a bit of a pain to use so maybe he's trying to make his life easier.

 

[Blunt Tool]

Yes definitely sounds as tho he is more interested in making his life easier and not what customer is wanting! Maybe he has never used epoxy, ask him.

 

[Tardigrade]

Thank you - total newbie so re: "movement joints":
1) is this something done in any event, or something I have to do BECAUSE I want epoxy grout?
2) Where are these things placed? It would seem to ruin the robustness if some proportion of the grout lines are just silicone or am I missing something?
3) In what scenarios would my builder have a point? Just so I can see if there is any risk I'm near them!

 

[Blunt Tool]

Internal joints should be clean and grout free ready for a matching silicone sealant finish. A wooden floor with too much movement would be unsuitable for epoxy grout unless overboarded to do away with any movement

 

[Tardigrade]

Thanks for the floor example. By internal joints, I take it you mean, as an example, the bit essentially between tiles and plasterboard in a 90 degree corner?

 

[Blunt Tool]

Silicone should be used in corners of one tiled wall leading onto another tiled wall, also around bath/shower and tiles

 

[Tardigrade]

Thank you again! - and sorry to be so pedantic but to 100% confirm this is done regardless of grout type?

 

[Blunt Tool]

Thank you again! - and sorry to be so pedantic but to 100% confirm this is done regardless of grout type?

Yes any grout type, you get exact matching colour silicones and grouts nowadays

 

[Tardigrade]

Perfect thanks so much