Under-tile heating question.....

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Newbie alert!! Hi everyone. :D

Apologies in advance for the impending essay!!

Anyway, regarding Under-tile insulation boards. We have P5 Chipboard suspended flooring both in the Hall and adjoining Bathroom. We understand that this isn't the ideal flooring base for tiles, but nevertheless we laid Travertine tiles in the hall with no problems (10mm tiles with 3mm adhesive bed, no heating).

Now we are going to do the bathroom and want to add heating (secondary, not primary heat source). The tiles we like are called Q-Rock Black (Topps Tiles) and are 8mm thick, which is quite thin for a floor tile, that I realise. We plan to fit heating using the loose cable, probably the 'Warmup' brand.

Our problem is this. Warmup say definately DO NOT tile onto Chipboard. Why?

So, the answer we figured is to fit backer-board of some kind, so decided to look at insulated boards as these should also reduce running costs. However, of course with the adjoining floor at 13mm, we are tight for height. Having said this, I don't mind a little difference as we are using the variable height door bars and these aren't bad.

Our choice appears to be :-

1. No backer-board. Running the risk of whatever 'Warmup' feel might happen in these circumstances and with no insulation.

2. Fit 6mm backer-board, from someone like 'Fastwarm'. This will of course keep the height down a little, taking us only 3-4mm above the adjoining floor (if we only screw them down).

3. Fit 10mm backer-board, from 'Warmup'. This will provide slightly better insulation, but take us 8mm above the adjoining floor.

On top of this, some manufacturers of boards say that their boards should be laid onto a bed of adhesive in addition to screwing them down. This would, of course add a further 3mm to the height, making the 6mm board option 6-7mm higher and the 10mm board option 11mm higher than the adjoining floor.

Please guide us as to what we should do!! :confused:

I would really like to fit the 10mm board, but aren't really sure if the 11mm differential is going to cause a major problem.

Thanks in advance!
 
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I daresay that you could get the addhesive (under the backing board) down to less than 3mm.

Whether or not you follow Warmup's recommendations is up to you, but maybe you should consider what would happen if you wanted to make a warranty claim? You wouldn't be able to say that the product was installed correctly.

In any case, whatever the finished height of the floor, you can always install a short ramp - whenever this happens to me I Email a drawing to a local capenter who makes me up a nicely made and fully laquered strip of mahogany (or whatever) to bridge the difference. I arrange that this ends up under the door so that it doesn't look odd.
 
The other option is to rip up the chipboard and replace with either 22mm T&G flooring ply or 25mm WBP ply and lay straight onto this. Either bedding the wire into a self leveler or putting the adhesive straight onto the wire and laying the tiles in one go.

I don't think the insulation makes a lot of difference on a first floor room, different if it were the ground floor. But you could always fit some insulation between the joists under the ply.

Jason
 
18mm wbp through out
an noggins an substrate wood preserved ...

doing this has just made you a KING /QUEEN


to ever buys this property in the future ,


alas the 70s an 80/90s were couldnt care less ...

before then you an I know our dads/an mothers were ALWAYS doing jobs around the house /maintaining the property ...

something we appear to of lost generally .... except here of course :) :)
 
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Thanks for your replies guys.

We have opted to stick with the P5 Chipboard, but we have also gone for the 10mm 'Warm-up' boards too. When laying the floor, I will and keep the deficit between the adjoining floors as low as possible. With all the best will in the world it will end up with a difference of around 10mm.

Cheers. :D
 
Christian and Beccy

in other words cheap an cheerful bodge job .........

tell it like it is at least , be honest with yourselfs
 
Moz said:
Christian and Beccy

in other words cheap an cheerful bodge job .........

tell it like it is at least , be honest with yourselfs

When I hear strories from Porcelanosa contractors of bathroom jobs costing several thousands of pounds, yet being laid on NON waterproof CHIPBOARD. Or if they are to tile/heat onto Concrete subfloor, the cement backer boards (if used) are not being fixed atall, I hardly think my job is a bodge-job. I strongly resent that remark. :rolleyes:
 
"we have also gone for the 10mm 'Warm-up' boards too. When laying the floor, I will and keep the deficit between the adjoining floors as low as possible"

a bodge job ...

WRONG FLOORING AS SAID BEFORE ...
 
I have installed underfloor heating in an extension which is joined to a conservatory, this is what I did.
The base flooring is tongue and grooved (treated) chipboard....as said above , not ideal.
Onto that I have put Thermal aqua panels which are 12mm thick and available from Wickes or any of the Tile warehouses and are about £13 per 1200x600 panel. Nothing needs to go underneath them just make sure you use duck tape to seal the joins. Also lay them to a pattern similar to brickwork bonding. Lay the heating mat (better than just cable in my opinion) to shape. This is where it got tricky. I used a hell of a lot of flexible adhesive( a must). At £23 per 10kg tub it got expensive as I used 11 tubs of the stuff due to the depth of the matting underneath. But it has worked out well. You have to make sure you use an electrical tester to test the resistance of the element at various stages of installation because otherwise you'll finish and find it doesnt work...especially as you have to wait about 8-10 weeks for the adhesive to totally dry out ( otherwise the heating will expand and contract the stuff and leave holes and pits)....I have no expertise at this, I just followed instructions However, Whilst at work my wife has grouted the flooring and left lots of grout onto the tile surface which has dried out.
I would welcome any quick solutions to getting it off without damaging the tiles.
Regards to all
 
Job_n_knock

hope you got a fully qualified electrician to sign that work off as competant ?

or else you will never sell your house without ..lol






Christian and Beccy

you came here with questions regarding flooring an I gave it ,

"We understand that this isn't the ideal flooring base for tiles"
you started as you meant to go on ..bodge job .....lol ....

"Our choice appears to be "
so why post here AT ALL !!!

"Please guide us as to what we should do!! "

then this whine ...lol




Your tiles WILL fail with heat under them on that substrate ,
Trust me ..........
I gave a professional opinion ........
but some people dont want help !!!


Fozzy bear hahahaha lol
 
Softus said:
Rock on Moz :)

You reckon? Appears to me that there is only one way and that is moz's way, well as far as he is concerned anyway. :rolleyes:

I came back to this thread detailing my desired game-plan as there may have been people wondering if/how I solved it. That's all. In actual fact, this was backed up by more than one tradesman, from whom I sought advice in the end.
 
Christian and Beccy

boooooo hooo hooo ... booooooooooo...hoooooooo..bo

I gave good advice an you , chose to call me..


Fozzy bear ,,YAYA YA YA , cheers , cheers , cheers , cheers , cheers , cheers , loll ol lol lol ..lol..lol..lol...lol......lol...lol everyone , loves fozzy ..
 
Moz, your manner of so-called answering looks very retarded. I am a member on many forums and am quite happy to have a keyboard-style argument on any one of them, but I came here for open-minded advice.

Whether you have professional knowledge or not, you replies are on a par with those of a 6-year-old child. :rolleyes:
 

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