underfloor heating - Insulation boards yes or no?

[papereyes]

Putting UFH in my bathroom (on top of wbp 18mm) and conservatory (concrete sub floor). Then laying porcelain tiles on top.

Do I need insulation boards or can i just install the mat?

Thanks

 

[tpt]

bathroom not really, conservatory - yes usually a very good idea unless is a very modern and well insulated house\sub floor

 

[Richard C]

I have electric UFH as the primary heat source in a 22 sq/m conservatory; it works extremely well but make sure you spec it at 200 watts per/sqm over heat reflecting backer boards or it wont cope! Electric UFH can also be expensive to run, especially if you try & keep the cons in use all year round. If you need 12 month use, you would do better to consider building either a garden room or a proper extension.

UFH heating in bathrooms & even kitchens is very much in vogue but, personally, I cant see the point in it as a secondary heat source in a bathroom & especially not a kitchen; these tend to be hot enough in any case. I know many folks that have gone to all the trouble & expense of installing it leave it switched off because it proves to be inconvenient & impractical in use. The problem is that if you leave it on all the time it’s expensive & if you switch it on the timer you’re restricted to using the room at the same times every day. If you switch it on add-hock, you will have to wait 30 minutes or longer due to the warm up time. In my experience, tiled bathroom floors aren’t cold in any case.

You should also be aware that electric UFH is notifyable building work requiring Part P compliance.