Laying new slab over underfloor heating.

[jim the plumb]

Hi Guys,

Just a bit of advice needed. I have electric underfloor heating on the open plan ground floor at home.

The original slab is concrete, then the electric wiring for heating and then laminate floor.

I want to replace the laminate with tiles but need a concrete base - so I want to concrete over the heating and then tile on top.

Is this do-able? Obviously I need to consider depth of concrete to allow the heat to still come through as this won't be easily reversible.

Any advice at all appreciated.

thanks jtp

[johnoo]

how much depth have you got ?
the ideal scenario would be to take up underfloor heating lay some celotex insulation relay the heating mat and lay a minimum of 5omm floor sceerd over the top
or if you have not got the room and the underfloor heating is already laid on the concrete i have seen some jobs where they lay the tiles straight on top i think this deends on the type of floor heating system you have cheers john

[Perry525]

You need to think very carefully about this.
If your UFH does not have any insulation under it.
And it should have at least four inches of polystyrene or similar.
Then your heating bills will go through the roof, as heat will go down as well as up.
You will just be throwing your money away.
Underfloor heating works best when it has four inches of insulation below it and a lightweight wood floor above.
Anything else and you will have a considerable time lag between turning the heating on and the floor feeling warm.
Another point. With a concrete floor it continues to emit heat long after you have turned it off.
The money you spent on heating that concrete block is then wasted.

[johnoo]

good point perry 525

[rose]

if you take a look in b&q they have a display for the underfloor heating

that might help

[TheDoctor5]

Last year 64% of the questions asked in our forum were answered within our DIY project pages at www.diydoctor.org.uk/projects.htm The project pages are now separated alphabetically and your answers are accompanied by diagrams and the ability to see, and buy, the tools and/or required to complete your project. Use our search box to look for your answer and save a great deal of time and money!