Gypsum screed in a wetroom?

[tommyzooom]

I'm on a new house at the moment, 100m of 900x450 porcelain, onto a sand and cement screed. This is phase one, I haven't been asked to price for the bathrooms (Yet)
For some reason, the rest of the house has a gypsum screed, including 3 of the 4 bathrooms. These are not that common over here, but I thought this type of screed was not suitable in a bathroom (one room is a wetroom!!)????
What advice should I arm myself with for when I am asked to quote for them? What prep work is needed? I guess they will need fully tanked? with a paint on tanking? If a membrane, what to stick it to the screed with?

A rip out will be a last resort as it has wet ufh too
tia

 

[Ajax123]

Gypsum screed is not suitable for areas where it will remain permanently wet so itis ok for a bathroom provided it is dried and then kept dry. My advice is be to make certain that once it is dry use a tanking membrane to waterproof it from the top.

I thinki would use ditra in this sort of area as well or something of that nature.

Do you know which gypsum screed itis. There are several in Ireland.

 

[tommyzooom]

No, I'm not sure which it is, but I can find out.
I thought about Ditra, what to stick it down with though?? A gypsum addy i guess would be best underneath, but will be very hard to source over here.

 

[The D]

[video=youtube;TjJHnKw7YNA]http://www.youtube.com/watch?v=TjJHnKw7YNA[/video]

 

[Ajax123]

If the screed is dry and you use a tanking membrane you will stop any sulphate migration so you will be able to stick the ditra down using a cement based flexible adhesive

 

[Ajax123]

[video=youtube;TjJHnKw7YNA]http://www.youtube.com/watch?v=TjJHnKw7YNA[/video]

I love that song. And as for my mate Fred and his bird Rita.....well that is Just class

 

[Peter]

Is this your first gypsum screed you've come across? Yet to see one here myself, be it for tiling or just in general flooring. Hoping they don't catch on here - sounds like a lot of headache.

 

[DHTiling]

They are very popular over here now.

I have done 4 large ones in past 18 months And another in July. So get educated , they ain't going away.

 

[doug boardley]

If the screed is dry and you use a tanking membrane you will stop any sulphate migration so you will be able to stick the ditra down using a cement based flexible adhesive

it'd still need priming though wouldn't it Alan?

 

[tommyzooom]

I've priced a few, including sanding and priming etc, but didn't get any. I assume they were tiled by the uninformed, who fired away!!!!!
Certainly getting more popular,

 

[Ajax123]

Is this your first gypsum screed you've come across? Yet to see one here myself, be it for tiling or just in general flooring. Hoping they don't catch on here - sounds like a lot of headache.

You are too late..... There are at least six suppliers now in ireland

 

[Ajax123]

it'd still need priming though wouldn't it Alan?

Now that is a good question. On the basis that the tanking membrane is water proof so will not allow the migration of moisture borne sulphates which is largely what causes the issues I would assume that it would act as a primer. However I am not sure how a tanking membrane should be used once applied. If you wold normally prime before taking the still do so. If you would normally prime after tanking again still do so. If however you would not normally prime when tanking then it should not be necessary....... Hmmmm! Time for a lesson myself methinks. Every days a school day eh!

 

[Ajax123]

For information nicobond have outlets for gypfix in Ireland