Tiling on Overfit board,

[NZ_Tiler]

I have a client down here in New Zealand with a product called Speedfit Overfit board (UK Product)

Can this be tiled over or is it only good for floating floors?

If tiling is ok what prep needs to happen over the top?

Communication with client is only per email so far, yet to see installation board installed.

TIA

 

[Old Mod]

Think it's this.
Not something I've used unfortunately, sorry.

John Guest Board systems - http://www.jtmplumbing.co.uk/john-guest-speedfit-c432/john-guest-speedfit-underfloor-heating-c131/john-guest-speedfit-john-guest-board-systems-pp4243

 

[Uheat - Jake]

If the panels have a foil on the top then they wouldn't be suitable for tiling directly on top. They'd have to have a ply overboard first.

 

[Spare Tool]

If the panels have a foil on the top then they wouldn't be suitable for tiling directly on top. They'd have to have a ply overboard first.

Thing is though Jake that if you mix ply with hot and cold its going to move, thats even if you lucky enough to miss every pipe when screwing it into the subfloor at 300's...only takes one screw.
I did one of these last year, it was discussed on here at the time...
Got the subfloor flat first, pipe boards were then fixed with spf, pipes were then pressured up, 10mm of Webber fibre SLC over it then ci matt then tiled with 600 porc and to my knowledge (ie. no complaints) its been fine.
None of the manufactures of these types of systems have 100% agreed with adhesive manufacturers just what to do with them, and one or the other will no doubt wriggle out of any warranties should any problems occur.

 

[Uheat - Jake]

Thing is though Jake that if you mix ply with hot and cold its going to move, thats even if you lucky enough to miss every pipe when screwing it into the subfloor at 300's...only takes one screw.
I did one of these last year, it was discussed on here at the time...
Got the subfloor flat first, pipe boards were then fixed with spf, pipes were then pressured up, 10mm of Webber fibre SLC over it then ci matt then tiled with 600 porc and to my knowledge (ie. no complaints) its been fine.
None of the manufactures of these types of systems have 100% agreed with adhesive manufacturers just what to do with them, and one or the other will no doubt wriggle out of any warranties should any problems occur.

We've recommended the ply for a long time and haven't had any problems to date, we've asked numerous times about tiling directly on top of the polystyrene boards but there's two answers we receive from the manufactures and that's the foil on the top will react with adhesive or the boards compressive strength isn't strong enough especially if it's a EPS150.

 

[Spare Tool]

We've recommended the ply for a long time and haven't had any problems to date, we've asked numerous times about tiling directly on top of the polystyrene boards but there's two answers we receive from the manufactures and that's the foil on the top will react with adhesive or the boards compressive strength isn't strong enough especially if it's a EPS150.

I spoke at length with J Guest about this particular job and got their RECOMMENDATIONS in writing, the email is on the forum somewhere, I stress recommendations as they wouldn't guarantee neither ply nor SLC, I then spoke to Webber who would then only recommend their products also. Just sat better with me to go down the slc route and as I say no problems in over a year.

 

[Old Mod]

I know of two recent cases where tiling direct to the foil has resulted in failures.
I certainly wouldn't, not now.
The foil layers had delaminated causing the whole floor to fail.

 

[Uheat - Jake]

I know of two recent cases where tiling direct to the foil has resulted in failures.
I certainly wouldn't, not now.
The foil layers had delaminated causing the whole floor to fail.

That's why we recommend our newer product which is a gypsum board and has no problem with tiling on, solid panel so no issues with overboarding while walking about the room. Cost's a slightly bit more, however is worth it in the long run.

 

[Spare Tool]

That's why we recommend our newer product which is a gypsum board and has no problem with tiling on, solid panel so no issues with overboarding while walking about the room. Cost's a slightly bit more, however is worth it in the long run.

View attachment 88791

Have you talked to any adhesive manufacturers to offer any comprehensive guarantee's on fixing straight on the boards?

 

[Uheat - Jake]

Have you talked to any adhesive manufacturers to offer any comprehensive guarantee's on fixing straight on the boards?

We haven't spoken to any manufactures about that, however the boards have been tested with Fermacell Adhesive as they are a Fermacell product.