Marmox plastic washers.

[judge]

Evening gang. Would there be an issue laying loose ufh cable over the top of plastic marmox washers i am glue n screwing to an upstairs chipboard floor.Or should i try and work the cable around them instead ?( The main reason i ask is the slight height difference itll make.) Obviously ill be self levelling afterwards before tiling.:smilewinkgrin:

 

[AliGage]

Why don't you use hardie instead?

 

[Qwerty]

No issues whatsoever going over them

 

[White Room]

I'd be using hardie to avoid going directly to chipboard....

 

[Qwerty]

I'd be using hardie to avoid going directly to chipboard....

I read it as he was gluing & screwing (Marmox) to the chipboard hence why using Marmox washers. I just assuming you meant that judge, not directly slc to chipboard?

 

[White Room]

I read it as he was gluing & screwing (Marmox) to the chipboard hence why using Marmox washers. I just assuming you meant that judge, not directly slc to chipboard?

You may be right Geoff I zeroed on the chipboard

 

[judge]

I was gonna glue n screw 6 mm insulation board ontop of the chipboard,tape the joints,lay the cable,then self level before tiling.I was just a little concerned about the slight height issue as the washers dont sit totally flush on the insulationboard when screwed down.(probablly worrying about nothing but wanted to check first):smilewinkgrin:

Ali-I allways overboard with Hardi but was only going with insulation board for the the thermal properties.

 

[White Room]

I prefer the metal washers, never used the plastic though....

 

[Rookery]

I use the metal ones too, no height issues then. Arent the plastic ones meant for hammer fixing into solid walls/floors?

 

[Qwerty]

I use the metal ones too, no height issues then. Arent the plastic ones meant for hammer fixing into solid walls/floors?

No mate. There are plastic washers that are identical to the metal ones, only difference is you can't screw down as much as metal ones as the screw just pulls through. I use them a lot still though. They do make plastic "spankers" for solid fixing.
Judge, by the time the screw is in nicely it will only be 1-2mm higher maximum

 

[AliGage]

Ali-I allways overboard with Hardi but was only going with insulation board for the the thermal properties.

I don't think there is much difference between the two mate 0.00something.
Over a timber floor though I would probably opt for hardie. Yes marmox is easier to handle, cut and fit. I've just done a bathroom with UFH, chipboard floor and went over with HBB and I'm starting another tomorrow where ill use the same.

Thats just how I roll! But if its marmox you intend to use and its loose wire youre fitting im sure you could work the wire round the washers. A little less depth on the SLC too.

 

[judge]

Thanks for the replies guys

 

[The D]

I don't think there is much difference between the two mate 0.00something.
Over a timber floor though I would probably opt for hardie. Yes marmox is easier to handle, cut and fit. I've just done a bathroom with UFH, chipboard floor and went over with HBB and I'm starting another tomorrow where ill use the same.

Thats just how I roll! But if its marmox you intend to use and its loose wire youre fitting im sure you could work the wire round the washers. A little less depth on the SLC too.

So Marmox is not a thermal board ??

 

[One Day]

HUGE difference between marmox/wedi/jacko etc and cement boards!
Why would anyone lay ufh on HB???

 

[One Day]

Infact -
Hardibacker 500 U value = 7.7
Marmox u value = 2.7

Big difference there.

 

[AliGage]

Never said marmox wasnt an insulation board deano.

Impish compare like for like sizing. 6mm marmox to 6mm hbb, not hbb 500. Yes there is a difference. But this is going over a timber floor, chipboard infact. Not concrete. Would consider structural strength rather than insulation values.

Would you choose 6mm marmox over 6mm hbb in this scenario then?

 

[One Day]

I was comparing 10mm marmox to 500HB - pretty fair no?
I'd never opt for 6mm HB or marmox to add strength.
In my experience 10mm insulation boards properly installed do add strength. I think if I ever face a floor which needs strengthening I would aim to strengthen it before overlaying anything prior to UFH.
I've used 6mm wedi boards on floors but only when really pushed for height - never to add strength and 6mm adds little insulation compared to 10mm anyways.

Does adding 6mm HB instead of marmox etc add more strength in your experience Ali?

 

[AliGage]

Judge was concerned over height issues so presumed he was looking at 6mm.

You seem to he missing my point or maybe im not explaining.

On the presumption of 6mm to bare height issues in mind, I would oot for hbb. No not to add strength, but you get more flex in marmox than hbb. Of course any deflection would be sorted beforehand, but you can't always guarantee it to be defection free entirely. After all it is timber. So on the basis that structually speaking hbb is better I would chose it and do.
My next question would be does a timber floor really require "insulating" timber being a resonable insulator itself whats important is having a barrier so the UFH doesnt warm the substrate and reducing heat transfer or lose. HBB does this, might not be as beneficial as an insulation board, but on a timber substrate I think its other properties more than makes up for it.

Just my opinion.

 

[AliGage]

Now if you gave me the ootion of a thicker grade of insulation board I'd be open to marmox, but 6mm I wouldn't.
I also wouldnt use 12mm hbb on the floor.

 

[The D]

Never said marmox wasnt an insulation board deano.

Impish compare like for like sizing. 6mm marmox to 6mm hbb, not hbb 500. Yes there is a difference. But this is going over a timber floor, chipboard infact. Not concrete. Would consider structural strength rather than insulation values.

Would you choose 6mm marmox over 6mm hbb in this scenario then?

hbb offers no strength and no insulation whereas extruded foam boards ofer both so in this instance I would go with marmox