COUPLE OF QUESTIONs

[southside]

Regarding underfloor heating in a house which has had a pumped screed (one level house) does a decoupling mat Have to be used? even in a area where tiling is small ie 10msq in total will latex in adhesive not do?

Do you have to backbutter large tiles such as Travertine ,porcelin on walls even when using a 10 m trowel?

[Dave]

Hello.

When you say pumped screed.. is it a cementious screed or an Anhydrite one,..?

[Phil Hobson]

I would go for de-coupling membrane, with ufh. Back butter all large format tiles, imo

[southside]

I would go for de-coupling membrane, with ufh. Back butter all large format tiles, imo

How do these membrane go down do they get glued ,adhesive whats the procedure?

[Phil Hobson]

How do these membrane go down do they get glued ,adhesive whats the procedure?

The membrane is cut to size, and then fixed using a flex adhesive eg. Mapei keraquick. Mixed slightly thinner than for fixing tiles. Use a 4mm notched trowel

[Rich]

Id go for the uncoupling as well.
When you say under floor heating, do you mean in screed (water) or heat mats (electric)?

[david campbell]

i would go for de-coupling also tend to need back-buttering with larger tiles

[doug boardley]

I'd uncouple too https://www.pureadhesion.co.uk/store...Data_Sheet.pdf

[southside]

Id go for the uncoupling as well.
When you say under floor heating, do you mean in screed (water) or heat mats (electric)?

sure its in screed water buddy

[southside]

The membrane is cut to size, and then fixed using a flex adhesive eg. Mapei keraquick. Mixed slightly thinner than for fixing tiles. Use a 4mm notched trowel

do you just lay ontop of adhesive or pat it down and do you have to wait a day before you can tile ?

will i still need to use latex with keriquick etc or will the membrane take care of moment on its own?

my worry is that the heating system has not been put on yet and wont be untill after tiling .

Sorry for the questions lads never tiled upon ufh just want exclude any risk factors that might be there.

[Phil Hobson]

do you just lay ontop of adhesive or pat it down and do you have to wait a day before you can tile ?

will i still need to use latex with keriquick etc or will the membrane take care of moment on its own?

my worry is that the heating system has not been put on yet and wont be untill after tiling .

Sorry for the questions lads never tiled upon ufh just want exclude any risk factors that might be there.

Sorry southside, but ufh should be commissioned prior to tiling. Lay onto adhesive, use plastic/ wood float to expell air. If poss leave overnight ,fill surface of membrane with adhesive then serate as usual for tiling On a solid floor latex plus is not necessary, but if within budget wouldn't hurt.

[merlecollins]

Do you have to backbutter large tiles such as Travertine ,porcelin on walls even when using a 10 m trowel?

I always backbutter as procedure with large tiles, you'll get a much better bond - and if you're fixing the trav on the floor, make sure you back skim them to fill any cavities in the stone

[Phil Hobson]

Just to add, after tiling. Floor should be left for two weeks, then heating brought up gradually no more than 5 deg in any 24hrs to optimum temp. left for 2 days, then brought down no more than 5 deg in any 24hrs. Hope this helps

[Dave]

It's ok saying to use this and that.. what screed is it..?

Different prep for either screed.

[Phil Hobson]

Sorry Dave, yeah we haven't established that yet.

[southside]

Will find out what screed and will get back to yous
cheers for the replies

[southside]

Sorry southside, but ufh should be commissioned prior to tiling. Lay onto adhesive, use plastic/ wood float to expell air. If poss leave overnight ,fill surface of membrane with adhesive then serate as usual for tiling On a solid floor latex plus is not necessary, but if within budget wouldn't hurt.

Cheers for the info PHIL ,Appreciated

[Ajax123]

Southside - are you a pro tiler....not wishing to be insulting but some of the questions seem pretty basic and heated screeds can be tricky blighters and pumped anhydrite even more so. If you are doing it DIY maybe it's worth hiring a pro in. If you are already a pro I apologise....just trying to help.

[nybor62]

if its hydrite it must be primered .i would use a thick bed pourable flexi addy 15mm trowel .i know folk go on about all these different types of mats theres no need for it

[Ajax123]

if it is anhydrite I would simply use Gypsum based adhesive and an acrylic primer. Try not to mix materials if possible (cement and anhydrite don't like each other)

[diamondtiling]

if its hydrite it must be primered .i would use a thick bed pourable flexi addy 15mm trowel .i know folk go on about all these different types of mats theres no need for it

What are you basing that statement on? Are you saying that it makes no difference what materials are used to fix the tiles?

[Phil Hobson]

Each to their own, as far as de-coupling membranes. I tend to err on the side of caution, I always explain to the customer the potential problems of uhf. Advise the use of the membrane, let them see the tech info, then it's their decision. Most go for it

[Ajax123]

What are you basing that statement on? Are you saying that it makes no difference what materials are used to fix the tiles?

On the contrary diamond. It makes a good deal of difference. Most tilers I have come across stick (excuse the pun) to the materials they have always used. When it comes to anhydrite we all know that it can be a difficult substrate and needs careful consideration. The more traditional materials present risks over anhydrite (especially when heated) which can be avoided by using GYpsum adhesives. These are used more routinely in mainland Europe but don't seem to have caught on so much over here. Maybe it is our good old British conservatism which prevents us from demanding it of the manuacturers especially those who already manufacture for the German, Dutch and French markets where anhydrite screeds are used routinely in small builds and single houses. Where Gypsum addy has been used there have been almost no issues.

[southside]

Southside - are you a pro tiler....not wishing to be insulting but some of the questions seem pretty basic and heated screeds can be tricky blighters and pumped anhydrite even more so. If you are doing it DIY maybe it's worth hiring a pro in. If you are already a pro I apologise....just trying to help.

Just never tile over Water ufh Tiled for over 15 years your always learning as they say only a basic procedure when you have done it before.

[Ajax123]

Just never tile over Water ufh Tiled for over 15 years your always learning as they say only a basic procedure when you have done it before.

No offense intended and it seems non taken so thank for taking my question graciously.