Marmox Boards on the Floor andUFH

[Ziggy1979]

Hi Everyone
After a couple of weeks worth of building, etc distraction I'll finally be starting the bathroom this week!


Thanks for all your help and advice so far!


I thought of buying the 2500mm 10mm & 12.5mm Marmox boards as room is approx 2500mm tall and floor is approx 2800x2400. Are the 2500mm boards hard to use? Would u recommend using the 1250mm ones instead?


Also, do I need to leave any expansion joints where the wall boards meet the floor/ceiling and where the floor boards meet the walls?


Finally floor is out of level by approx 10mm across the 2400mm width of the room. Is it ok/possible to level this by using more tile adhesive under the marmox board? They are going over 25mm WBP Ply (thought of using Keraquick without added latex).


Thank u all so much again!!! 🙂


Sent from my iPhone

 

[Qwerty]

Use the 1250 boards, yes do incorporate expansion joints and use SLC to level after laying the UFH.

 

[Ziggy1979]

Hi Everyone

ive finally dot and dabbed the boards. It was a lot easier and less intimidating than I thought it would be...thank god!

I now need to drill through and screw with metal washers (instead of the plastic hammer in dowels). I think it's a dumb question but do I use normal red or brown rawl plugs which won't go much deeper than the keraquick dabs or should I use other fixings that go deep into the brick walls behind?

thanks again for your help!

 

[Qwerty]

Normal rawl type plugs just fine. Drill through further to allow for the depth as you say. The rawl plugs should be into the wall though for a solid fixing. Did you pre drill the board prior to spot fixing?

 

[Ziggy1979]

Thanks PTT

I punched 5 holes with a screw driver and put large dots over them. I also put dabs all over the edges and many more in the middle. Tbh it looked like overkill but the boards are 12 mm and I was worried about them flexing if there wasn't enough adhesive (did seem to use a lot of Keraquick though (and its pricey).

Ok...so shall I drill a bigger hole (eg 8mm) in the marmox/dot/dab and then a 6mm hole (for the rawl plug) in the brick? I've bought 50mm long stainless turbo ultras so hopefully they'll be long enough to reach.

For the bath panel, can I build a frame out of 2x1 and fix 12 mm boards to this? Should/can the bath sit on the frame? If not, how should I secure it? The reason for 2x1 is so that the tiled finish is flush with the edge of the bath. I have to make a tiled panel for the top end and one side of the bath with access for the taps/trap.

thanks again!

 

[Qwerty]

No, just use a 6mm bit to drill through both but you just need to ensure the rawl plug is in the wall securely.
As for the frame, I would try to use cls if it will allow. Fix frame securely to walls and floor (can even use a mastic type adhesive across the top where it adjoins the bath.) Make sure it is a solid rigid frame for the marmox to fix to. You can use thinner marmox here if you like. Two vertical uprights within the frame should suffice. I often use keku or magnetic fixings for hidden panels with a neat bead of Silicon instead of grout.

 

[Ziggy1979]

Thanks again PTT 🙂

For the CLS frame, what sized timber is the minimum I can safely get away with? The edge of the bath isn't very wide and I think the tiles (marble) will be about 15mm so I'm not sure ill be able to use 3x2.

for the hidden panels, do u fix the keku/magnets to the back of the marmox board? If so, can't the screw rip off the marmox when pulling the panel out?

Thanks! 🙂

 

[Qwerty]

Basically you need to use the biggest size you can get away with under there. I use 3x2 if I can. I screw through from the face of the marmox using a washer to spread the load but use screws that screw into the plastic holes of the keku fixings. Once tiled over on the front it is a very solid fixing!

 

[Ajax123]

You have a floor area approximately 2.4x3m = 7.2m2 based on a 100w/m2 mat you will get a heat output of just 720w per hour. That dies not allow for any downward heat loss. You need to calculate the rooms heat loss to see if 720w/h will overcome the heat loss. If the heat loss is more than 720 your room will never warm up ad your electricity bill will be huge.