Hello,
I have lifted the stone flags in our kitchen and want to re-lay them, with
insulation and wet underfloor heating.
We have dug the clay out to a depth of 300mm below the finished surface and
my intention is to lay 25mm sand, DPM, 25mm sand, 80mm kingspan, fix UFH
pipes to surface, screeded over to protect during flag laying ( not sure of
depth of screed needed), then a solid bed of sand/cement to lay the flags
on, probably one flag at a time.
Does this sound like reasonable construction for the floor and has anyone
got reccomendations for the UFH, I think 22mm might be prefferable, to raise
the temperature quicker.
Cheers,
Tony.

On Wed, 09 Apr 2008 19:29:05 +0100, Tony wrote:

Hello,
I have lifted the stone flags in our kitchen and want to re-lay them, with
insulation and wet underfloor heating.

The UFH article on the DIY wiki has links to maunfacturers' publications
on how to do UFH, which should answer most of your questions.
http://wiki.diyfaq.org.uk IIRC

--
John Stumbles

87.5% of statistics are made up

"Tony" wrote in message
...
Hello,
I have lifted the stone flags in our kitchen and want to re-lay them, with
insulation and wet underfloor heating.
We have dug the clay out to a depth of 300mm below the finished surface
and my intention is to lay 25mm sand, DPM, 25mm sand, 80mm kingspan, fix
UFH pipes to surface, screeded over to protect during flag laying ( not
sure of depth of screed needed), then a solid bed of sand/cement to lay
the flags on, probably one flag at a time.
Does this sound like reasonable construction for the floor and has anyone
got reccomendations for the UFH, I think 22mm might be prefferable, to
raise the temperature quicker.
Cheers,
Tony.



You probably need to check building regs.
Even if you don't the building inspectors usually offer good advice for
nothing.

Tony wrote:
Hello,
I have lifted the stone flags in our kitchen and want to re-lay them, with
insulation and wet underfloor heating.
We have dug the clay out to a depth of 300mm below the finished surface and
my intention is to lay 25mm sand, DPM, 25mm sand, 80mm kingspan, fix UFH
pipes to surface, screeded over to protect during flag laying ( not sure of
depth of screed needed), then a solid bed of sand/cement to lay the flags
on, probably one flag at a time.
Does this sound like reasonable construction for the floor and has anyone
got reccomendations for the UFH, I think 22mm might be prefferable, to raise
the temperature quicker.
Cheers,
Tony.


No. I am fairly sure you need to lay a proper concrete floor first,
possibly with rebar, to prevent soil movement from cracking the lot,
then go DPM and insulation, then pipes and screed.

I'd say 100mm concrete/rebar, 75mm kingspan and 75mm screed is about
right, and then lay stone on top of that.