Help!: water underfloor heating with no screed

[ms.tiles]

Hi all

Ive been to look at a job, its a nice big one 130+ mtrs but there is insulation boards on top of plywood. The insulation boards hold 10mm or so pipework which is the heating system, the pipes are just below the surface. The builder has said i can tile straight on top of this.
Is this correct as ive always thought there should be a sand and cement screed on top which should be min of 50mm. I called a plumber who fits the water underfloor heating systems but he hasnt come across this before.

the tiles are 600x600 porcelain,not polished and as the floor is flat so i can get a few day down quickly.
just the underfloor heating is stopping me putting the estimate in until im happy i know enough about it.
the builder said its fine, any thoughts from the pro's????

Thank you in advance
MS Tiles

[Ajax123]

there are a few specifically designed systems that can be tiled straight onto without the need for a screed but if it is just insulation then I suspect it is not suitable. Do you know what system it is?

[ms.tiles]

hi

its a proper underfloor heating system and the insulation boards are made for the pipes to run in. the problem is i dont have the name of it.

has anybody actual tiled onto it before.
The boards are light grey and it has black ends for the pipes to return back and down the next run. there are 4 runs of pipe per board. they have screwed the boards to the ply and it looks like silicone or some form of glue between each board.
sorry for it being a bit vague.

[Ajax123]

does it look anything like this

Polypipe Building Products | Overlay Home | Polypipe - Water Management, Underground Drainage, Flexible Plumbing Systems, Underfloor Heating

[ms.tiles]

That looks like it. thats great thank you very much.
i'll read it all later.
Have you tiled onto it yourself?? the builder is supplying adhesive and grout. i'll state flexible products in estimate.

[Del W]

Had a quick read,couldnt see anything about tiles.Let us know outcome.

[whitebeam]

Only shows a wood floor.

[Dave]

Be careful, most of the time these systems are laid loose on substrate, so in theory it is a floating floor..

[ms.tiles]

hi all

Polypipe Building Products | Overlay - Choice | Polypipe - Water Management, Underground Drainage, Flexible Plumbing Systems, Underfloor Heating

shows 2 different systems but one shows tiles on directly on top.
the lite system needs ply on top for tiles i'll need to find out what is down if this is the actual system used.

[ms.tiles]

the boards are screwed down

[Dave]

As long as it is Solid then an S1 adhesive will suffice.. but always check suitability with manufacture of adhesive.

[ms.tiles]

hi
i always use weber spf rapid when i need flexible adhesive and ardex fl grouts. hopefully the builder can supply these,i know the tile shop he uses have ardex grouts.
i'll call weber tomorrow and ask them.
the floor was solid from what i could tell although i will pop back and check it again when i get 5 mins.

Thank you everybody for the info and advice, very helpful and i appreciate it

[thompsonbrown]

if its the poly plumb system then your fine. but let the heating engineer fit the system fitted a 30mtr kit in a conserver try ended up using 4 sheets of kingspan and 100kg of self leveler also system runs at over c alot hotter than most warm water heating systems double the amount of baggie needs

[Ajax123]

That looks like it. thats great thank you very much.
i'll read it all later.
Have you tiled onto it yourself?? the builder is supplying adhesive and grout. i'll state flexible products in estimate.

No not I - I hate the system cos I sell screeds. I don't hate it because it is a poor system....it is probably very good....I just hate it on principal