As part of my bathroom refurbishment, I'm looking to purchase an UFH kit from either Omnie or Continental Underfloor. They both sell a system using 22mm chipboard that has been routed to accept 12mm UFH pipes.
My bathroom previously had 18mm chipboard with 9mm (I think) plywood sheets screwed and glued and then tiled over. No issues with the tiles in 22 years!
I have already removed all the flooring.
The Omnie boards are called torfloor and details can be found here.
The Continental boards are called oneboard and details can be found here.
Both systems are identical in terms of installation. Because the boards are pre-grooved they must be strengthened by gluing and screwing a minimum of 6mm plywood sheets. Because the boards have pipes running along them, the glue and screws can only be placed between the pipes.
While I understand that the 22mm routed boards require the plywood to complete their structural integrity, I don't like the idea of having wooden sheets above the UFH as wood is not a good conductor of heat.
I considered using Hardiebacker boards, 6mm or possibly 12mm as these are cement boards and so will be much better at conducting the heat and I get the impression they are just as strong as ply, if not stronger. However, Hardiebacker boards must be laid on a full layer of adhesive and I'm not keen on the idea of putting adhesive over all the pipes.
Another possibility would be no more ply as this can be installed using grab adhesive, so I assume I could just run the adhesive between the pipes, like I would when gluing ply. The problem with no more ply is that I believe it is thermally insulating, so I assume it would stop the heat getting through to the tiles that will be fixed to the board.
Another issue is that both Continental and Omnie state that unless 6mm or greater ply is used they can't offer any guarantees. They have never tested their system using Hardiebacker or any other type of board, only ply. In this day and age, that's a shame given their are so many different products available on the market.
Another possibility would be to glue and screw 6mm ply to the routed boards (meeting their guarantee requirements), and then fix 6mm hardiebacker board to the ply. This feels like it ticks all the boxes (although I still have sheets of wood over the UFH), but it will be a lot of work!
I would appreciate your thoughts and guidance on the different over-boarding solutions.
What would you do?
My bathroom previously had 18mm chipboard with 9mm (I think) plywood sheets screwed and glued and then tiled over. No issues with the tiles in 22 years!
I have already removed all the flooring.
The Omnie boards are called torfloor and details can be found here.
The Continental boards are called oneboard and details can be found here.
Both systems are identical in terms of installation. Because the boards are pre-grooved they must be strengthened by gluing and screwing a minimum of 6mm plywood sheets. Because the boards have pipes running along them, the glue and screws can only be placed between the pipes.
While I understand that the 22mm routed boards require the plywood to complete their structural integrity, I don't like the idea of having wooden sheets above the UFH as wood is not a good conductor of heat.
I considered using Hardiebacker boards, 6mm or possibly 12mm as these are cement boards and so will be much better at conducting the heat and I get the impression they are just as strong as ply, if not stronger. However, Hardiebacker boards must be laid on a full layer of adhesive and I'm not keen on the idea of putting adhesive over all the pipes.
Another possibility would be no more ply as this can be installed using grab adhesive, so I assume I could just run the adhesive between the pipes, like I would when gluing ply. The problem with no more ply is that I believe it is thermally insulating, so I assume it would stop the heat getting through to the tiles that will be fixed to the board.
Another issue is that both Continental and Omnie state that unless 6mm or greater ply is used they can't offer any guarantees. They have never tested their system using Hardiebacker or any other type of board, only ply. In this day and age, that's a shame given their are so many different products available on the market.
Another possibility would be to glue and screw 6mm ply to the routed boards (meeting their guarantee requirements), and then fix 6mm hardiebacker board to the ply. This feels like it ticks all the boxes (although I still have sheets of wood over the UFH), but it will be a lot of work!
I would appreciate your thoughts and guidance on the different over-boarding solutions.
What would you do?
