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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Painting, Decorating & Tiling Questions >> undeer tile heating https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1157667906 Message started by scotspark on Sep 7^th, 2006, 11:25pm

Title: undeer tile heating
Post by scotspark on Sep 7^th, 2006, 11:25pm

Have just fitted some electric under tile heating in a bathroom and was talking to tiler about how long to leave before switching it on.

he said a week minimum so I have said a month

but he said it should only be turned on twice a day for an hour or the adhesive becomes baked????????????

i thot this stuff was left on all the time

it is only a 150 watt with no backing board jujst onto ply as tech dept said i din't need a backing board with the 150 watt set

Cheers :)

Scotspark

Title: Re: undeer tile heating
Post by AndyOlds on Sep 8^th, 2006, 12:13am

Hi Scotspark,

I have to say straight off I'm certainly no expert, but I've also recently installed underfloor heating in my bathroom. Like you, it's only 150W as the room is tiny. After reading the advice on here and elsewhere, I decided to put a layer of Aquapanel concrete sheets down on top of the floorboards first, and then bed the heating mat in BAL multibase (apparently, the concrete sheets help to reflect more of the heat upwards, rather than being absorbed straight into the floorboards and the multibase provides a totally flat base to lay the tiles on).

I certainly want to leave it on for more than a couple of hours a day - especially in the winter! I've not seen any advice anywhere to say this will cause a problem with the adhesive (as long as you've used the flexible stuff). If that was the case, it would be a pretty useless system!

Are you sure your tiler's used the correct adhesive and grout?

Title: Re: undeer tile heating
Post by jasonB on Sep 8^th, 2006, 10:17am

I always say a month before the (electric) UFH should be used, although the adhesive will set in a few hours (24 if not rapid set) it does not reach its full strength until 28days, infact the curve flattens out to almost full at that stage but it continues to harden over a much longer period.

There is no problem leaving the heating on for prolonged periods. Depending on what controller you use you can have a backgrounfd level that the floor will not drop below and a comfort level that can be set when you want.

I usually set bathrooms to come on 6.30-9.00 & 8.00-11.30, most customers seem happy with this and there is a boost button if they want extra heating in the day much like central heating controls.

Jason

Title: Re: undeer tile heating
Post by CWatters on Sep 8^th, 2006, 6:43pm

We're about to lay stone over UFH and my builder told me today that I need to mention we have UFH to the stone supplier because the adhesive he supplies will be different for those areas. Not sure if it's different for tiles.

Title: Re: undeer tile heating
Post by jasonB on Sep 8^th, 2006, 8:05pm

You need a flexible adhesive even if going onto a solid concrete/screed floor when using UFH to take up any expansion/contraction.

Jason

Title: Re: undeer tile heating
Post by scotspark on Sep 10^th, 2006, 2:43pm

cheers

I spoke to the tec dept and she said no need for the backing boards if she had said they improved the performance I would have had them fitted instead of the ply the builders put down >:( >:( >:(

as the job is for my brother price isn't really an issue because of the saving he is making on labour :'( ;D

tiles are down now and will leave for at least a month it is only for background heat as there is a towel rad on the central heating system in the bathroom.

not to sure if there is different levels of control but the digital stat/timeclock is outside the bathroom with a probe in the centre of the floor.

SS

Title: Re: undeer tile heating
Post by jasonB on Sep 10^th, 2006, 3:10pm

The thermal panels are not structural, you would have needed them in addition to the plywood, only really worth fitting on an uninsulated solid ground floor.

Jason