What adhesive and grout to use

[matt_w18]

Hi guys,

I'm doing up both my kitchen and bathroom in preparation of an additional family member and have opted for underfloor heating. My house is an old Victorian building with poor insulation and the UFH is to the primary, if not only, heat source in each room. After speaking with Perfect Heat they recommended 200watts per square meter and 10mm thermopanel tile backer boards with Warmsole underfloor heat cable wire. With a baby on the way I want to be sure each room is adequately heated, does anyone have any comments on this?

The first question is how to secure the boards to the floor. The kitchen has a concrete floor and the bathroom has wooden flooring. I have purchased some no more nails for the kitchen boards, which are suitable for UFH and was planning on screwing the boards to the floor in the kitchen. The second question is what adhesive and grout to use on top of the UFH. I have heard some bad things about Unibond, who seem to be the only people in any of my local DIY/tile shops that say the adhesive and grout is suitable for UFH. I have heard some good things about Mapei and wanted some advice on which is best for my specific areas. The tiles are porcelain in both rooms with the kitchen being 12 square meters with 60x60 tiles and bathroom is 3.5 square meters with 45x45 tiles.

Thanks I advance for any advice.

Matt

 

[kilty55]

hello matt.ufloor heating will not heat your rooms to the same degree as a heating system,i wouldnt really treat it as an alternative to that,im not sure if thats what you mean?

insulation boards are fixed using flexible tile cement basd adhesive tot he floor using a thin trowel,you mention 2 substartes concrete and also wooden boards are these 2 rooms adjoining at all?

 

[matt_w18]

Hi Kilty,

Thanks for your response.

No, the two rooms are not adjoining and are actually on different levels. The kitchen is on the ground floor, hence the concrete and the bathroom on the first floor, hence wooden boards. So am I correct in thinking the same adhesive used for fixing the tiles will also be adequate for fixing the insulation boards? (although I still do not know which one is best)

And yes, I was meaning as an alternate to a radiator. The way the kitchen is being moved around means its difficult to reposition a radiator and it will be a bit of an eye saw too. Even with a 1300watt cable in the kitchen, do you feel I will need an additional heat source?

 

[kilty55]

hello mat,,yes i dont think ufloor heating will heat a room im afraid,are you installing ufh only because you need the rooms heated? cant you add a wall mounted tall radiator and incorporate it into your kitchen plans?

i fix insulation boards with flexible cement based adhesive,ive never used the ones your talking about personally maybe another fixer on here can specify if those type are the same as most others, and yes it would be the same addhesive for the tiles,,flexible and make sure its suitable for porcelain,mapei keraquik would be good for this,,all mapei grouts will also be suitable for your installation they have good colour range too

 

[matt_w18]

Hi Kilty, thanks again for your responce.

The idea of UFH was more because I was re-tiling the floors in both rooms and I thought why not, and if I could get rid of the radiators in either room then it was an added bonus. The bathroom is very badly insulated, and even with the radiator I currently have, the room is always very cold in the winter, even if the heating has been on all night! Even if this just takes the chill off the floor/room I'll be happy.

I purchased some Mapei Keraquick the weekend, for a good price I think too. Screwfix wanted £9 for a 5kg bag and I got the 20kg bags for £18 instead.

Thanks for your help, all to do now is get started :smilewinkgrin:

 

[kilty55]

hi matt no probs,if your bathroom is so cold do you have cavity wall insulation? if its an option most local authoritys are doing schemes where you may be able to get it installed free of charge

 

[matt_w18]

No, the walls are mostly solid brick. My property is an old Victorian building where the toilet has been retrofitted to the property some time after it being built. It means it like a conservatory that sticks out the back of the house and has 3 walls that are external, all being solid brick, a flat roof above and a utility room below that like the bathroom has 3 external brick walls but actually has no form of heating at all. The window is also single glassed with wooden frames. The whole insulation side of my property leaves a lot to be desired...