Underfloor heating between joists

[Simon Dale]

Hi all
Just looked at a job where builder wants to put down 22m chipboard over joists then Ditra. I said nooooo. The heating system is wet on a polystyrene board with aluminium trays screwed to joists. I have mentioned giffa flooring. The joists are 400 centres so could probably use the 18mm. Any advice on this would be helpful as the builder will do whats best for a change.

 

[Waluigi]

Sounds like a job for Hardibacker, No more ply, Pro Ply or that Dukkaboard XL

I know for a fact that Pro ply is designed to go above UFH systems as I’ve read the technical data sheet. Not entirely sure on the others although it’s widely known that HB is OK above UFH.

Would have to be a thicker board though which limits some choices

 

[Simon Dale]

Sounds like a job for Hardibacker, No more ply, Pro Ply or that Dukkaboard XL

I know for a fact that Pro ply is designed to go above UFH systems as I’ve read the technical data sheet. Not entirely sure on the others although it’s widely known that HB is OK above UFH.

Would have to be a thicker board though which limits some choices

Im not in Hardie good books at the moment

 

[Tile Shop]

Im not in Hardie good books at the moment

Intrigued ..... what did you do?

 

[Waluigi]

Probably said it’s carcinogenic in front of 100 people all wearing those damn Hardibacker hoodies.

 

[Blunt Tool]

Im not in Hardie good books at the moment

What did you do Laurel?

 

[Tile Shop]

Probably said it’s carcinogenic in front of 100 people all wearing those damn Hardibacker hoodies.

Ahhh.... that would explain it. Comments like that usually go down like a fart in a lift.

 

[Simon Dale]

Intrigued ..... what did you do?

Posted someone else floor . It was 18mm ply ditra and 1800x900 6mm tile. Its been down for 2 years with wet underfloor between joists not a crack in sight solid as a rock. I said basically who needs Hardie

 

[Simon Dale]

Posted on TT its kicking off again Seems everything I post on there gets people angry

 

[Waluigi]

Not that angry if you’re still on there

 

[Simon Dale]

Not that angry if you’re still on there

I just rant occasionally. Spoke with Bal technical not much joy even with Giffa floor

 

[Waluigi]

I’d look into NMP

 

[Simon Dale]

I’d look into NMP

I would like to use minimum 18mm ?

 

[Simon Dale]

Just looked they do 22mm

 

[Waluigi]

Yes, 3_fall swears by it.

You might swear when you see the price.