New kitchen floor - best material?

[Katie279]

Hi all,

ok am planning to tile kitchen floor and install electric UFH.

have stripped right back to squeaky floorboards and would appreciate some advice on best way to tile to ensure a super solid and heat insulated surface!

from what I've researched people seem to highly recommend using marmox board over hardibacker etc when using UFH, however they also say marmot is a bit more flexible than hardibacker.

so I have choices and would appreciate your expert advice on what's belt and braces and what's pointless overkill.

Option 1
- rip up floorboards
- replace with 18mm WBC ply
- lay 12mm marmox board
- UFH
- slc
- tile

Option 2
- screw down floorboards
- lay 12mm marmox board
- uFh
- slc
- tile

im assuming hardibacker etc can't be laid instead of floorboards/plywood? If not I guess that could be an option too!

many thanks in advance!

 

[DHTiling]

Hi Katie , the floor should be solid before using Marmox etc anyway... and no IMO marmox does not deflect more than hardibacker.. and also 10mmmarmox would be ok for UFH , as on a timber substrate it will be around the 100w sqr mtr system... but some will allow upto 150w/160w whe using marmox over timber... but best to check with supplier.

 

[cam_low]

belt and braces option 1, option 2 will work too.

 

[Katie279]

Thanks guys, some great help!

Dave - interesting you mention re wattage, was pondering 200w UFH kits, so what do you mean by it'd 'work'. Is this an efficiency thing or a safety one?

 

[Mr Tiler]

hardi cant replace floor boards either

 

[Martyn Leeds]

What's your Tiler's input / ideas on the floor prep??

 

[cam_low]

I think shes doing it herself, am I right katie ?

 

[DHTiling]

Thanks guys, some great help!

Dave - interesting you mention re wattage, was pondering 200w UFH kits, so what do you mean by it'd 'work'. Is this an efficiency thing or a safety one?

You cannot use a 200w system. They are for conservatories etc.


Sent from my iPhone using Tapatalk 2

 

[Qwerty]

No requirement for 200w in wooden floors

 

[Ajax123]

Are the floor boards on joists? If so how deep are they. The more insulation the better and as you will probably need to take up the parts it gives you a perfect opportunity to put insulation between the joists. If this is an option your floor would be a whole lot warmer. Also if you are set on electric underfloor heating you would be far better off using a gypsum based levelling compound over it due to the higher thermal conductivity. You may even be able to install a wet system screened between the joists.

Dn get too fixed on just one possibility. If the boards are to come up ou have numerous options.

 

[Protilers]

IMO......rip up the floor boards......and put "noggins between the joists @400mm spacing".....then overlay with 18mm WBP Ply......glued and screwed to the joists and noggins.......(polyeurothane)
then if the surface is not "flat".....use a Flexible SLC.....to flatten the floor.....then install 6/10mm insulation boards in a brick bond fashion......(or herringbone)(using flexi tile adhesive and screws
(to bite into the ply below!) with Wedi/marmox washers!)

install heatmat......and SLC over the wires.....then install the tiles!.......

but this is just one opinion......and it is mine!

heehhehheeeeeee

all the best

Lee

 

[Protilers]

you can use 200w (sole source heating).......but it will need a direct "feed" back to the consumer unit (fuse box)....and it can NOT BE INSTALLED ON A SPUR (NOR A FUSED SPUR!).........
THIS COULD BE DETRIMENTAL TO YOUR HOUSEHOLD!!!!.....

all the best

Lee

 

[Protilers]

stick with 150/160 watt..........you can do two 10m2 mats (20m2) on one [email protected] install it on a spur........provided it is an RCD spur!....but that is the max!......i believe......

Lee

 

[Ajax123]

stick with 150/160 watt..........you can do two 10m2 mats (20m2) on one [email protected] install it on a spur........provided it is an RCD spur!....but that is the max!......i believe......

Lee

current building regs do not allow you to use a spur in a kitchen as far as I know. All sockets and PowerPoints must be on a ring except the cooker and a boiler which can be on separate but dedicated radial circuits. I am happy to be corrected though.... AND regardless of spur or not as it is an electrical installation in a kitchen which makes it notifiable under part p of the regs. it MUST meet part p of the regs so will need to be installed and certified by a qualified electrician who is a member of a competent persons scheme. Most building control authorities will not certify this type of work for you. It is NOT a DIY job.

 

[Protilers]

current building regs do not allow you to use a spur in a kitchen as far as I know. All sockets and PowerPoints must be on a ring except the cooker and a boiler which can be on separate but dedicated radial circuits. I am happy to be corrected though.... AND regardless of spur or not as it is an electrical installation in a kitchen which makes it notifiable under part p of the regs. it MUST meet part p of the regs so will need to be installed and certified by a qualified electrician who is a member of a competent persons scheme. Most building control authorities will not certify this type of work for you. It is NOT a DIY job.

cookers require 6mm cable...........(no one else in the house uses that!) boilers should always be independant (just because its sensible!)...............due to the fact that they are always on........(even when they are off!)......
but a "radial" is just a glorified spur!!!!!!.........IMO......

anyway.............all the best

Lee

 

[Protilers]

Radial loom:

View attachment 53244

 

[Protilers]

Ring Loom:

View attachment 53245

 

[Protilers]

but you could argue that a couple of those sockets are "spurs"......nite nite........

All the best

Lee

 

[Ajax123]

Cable size is dependent on current loading. My cooker actually runs on 10mm cable (diversity included) but would need 16mm if I didn't allow or diversity. So house builders are putting 4mm in which in my opinion is dangerous.

As for arguing that there might be spurs all I know is that current regs don't allow spurs for sockets in a kitchen.

I certainly brings into question all the UFH installations being done by tilers. Because I beleive this would be cased as fixed wiring it MUST be installed and certified to part p to meet the regs...

 

[Katie279]

Brilliant, thanks all!

spoke to electrician who couldn't see what the issue with 200w would be, indeed like me he was thinking it'd offer better performance at very little difference in running costs. Is on separate 20amp run so miles below limit (don't worry have an MEng in electrical engineering, so not completely daft in these matters!)

whats the thoughts on decoupling membranes? Seen a few posts saying these are essential when using UFH with tiles? Are these required?