electric ufh on plywood

[Mike]

I've been to see a job today where the tiles have lifted (i never laid them, i was too busy so the customer had to get someone else) 300 x 300 ceramics on ordinary ply. don't know what thickness yet. the ufh heating wire is of course ruined too, it was switched on fully almost immediatley after tiles were laid:yikes: the customer is getting a joiner to change boards to 25mm marine ply and after me recommending she has got some new ufh cable from u-heat. i will be priming the boards prior to re-laying the tiles with rapid set flexi. would you lay any differently? i've done this many times but just checking due to the tiles already failing. i know it's prob due to heating on straight away and wrong ply. cheers guys. mike

 

[Ian]

I always like to lay the matting on an insulation board or a cement board so if you could add that into the equation that would be good. The SLC and addy stick much better to the boards than ply.

 

[Rich]

I would over board with a cement board as well if given the choice, also I woulnt prime the ply as the manufacturer I use (Mapei) doesnt recommend it. May be different with other brands tho. 1 last thing, make sure that the heat mat is recommended for ply

 

[Rich]

I always like to lay the matting on an insulation board or a cement board so if you could add that into the equation that would be good. The SLC and addy stick much better to the boards than ply.

Beat me to the punch

 

[Ceramico tiling]

6-10 mm wedi over the ply,should act as insulation aswell,,or so im told.Prime the ply and fasten wedi with adhesive and mechanically.place underfloor heating then 2 part mappei levelling compound over the wires....Then ditra to top it all off.This is the system the contractor i work for uses on very high end properties in london and he has not had any complaints,,,

 

[Mike]

i thought you coulnt put slc over the ufh as its on ply not concrete? and there s no matting , it's just the cable only type

 

[Stewart]

Slc on ply Is fine as long as it's specified for that purpose.....

 

[Ceramico tiling]

i tank and tape all the wedi first in the joints and corners,,,I am new to this particular system,what is the problem with slc and ply?

 

[Mike]

i tank and tape all the wedi first in the joints and corners,,,I am new to this particular system,what is the problem with slc and ply?

i was led to believe it wasnt flexible enough unlike flexi addy. also i've never seen it mentioned on the instructions of the different slc's i've used

 

[Time's Ran Out]

Use the Mapei Fibreplan.

 

[Mike]

i'll try get that tomorrow thanks john

 

[Gazzer]

Use the Mapei Fibreplan.

Get Mapei Renovation screed, its half the price and awesome stuff to use.
View attachment ultraplan renovation_uk.pdf

 

[White Room]

Use the Mapei Fibreplan.

Last time I asked for Fibreplan, was asked if it was a diet, walked out

 

[Daz]

I often use Ardex Arditex NA over slc on ply, but would always prefer to overboard prior to installing the UFH.

 

[Mike]

I always like to lay the matting on an insulation board or a cement board so if you could add that into the equation that would be good. Place under floor heating then 2 part mapped leveling compound over the wires. Thanks.

that's how i did it, a long time ago i may add, this is an old thread