Hi all

I've just bought a 1950's bungalow and would like to install a wet
underfloor heating system. The floor construction is suspended
floorboards. Under these there is a void approx 50cm deep. The total
area of floor is about 90sq metres.

I understand that fitting underfloor heating to a suspended floor can
be problematic in terms of installation and efficiency.

As a relative newcomer to DIY I wondered if it would be best just
ripping up the existing floorboards and removing the joists then
filling the void and making a solid floor? If so, a few questions:

1. What would I fill the void with?
2. Would there be a consequence of the weight of the material I use as
infill?
3. How much is this likely to cost?

or does anyone have any other ideas?

I look forward to hearing from anyone with any advice whatsoever.

Cheers

Ben

I understand that fitting underfloor heating to a suspended floor can
be problematic in terms of installation and efficiency.

It is fine, although maximum output is limited compared to a solid
installation. This is only a problem if the wall insulation isn't up to
scratch, or it is a conservatory.

As a relative newcomer to DIY I wondered if it would be best just
ripping up the existing floorboards and removing the joists then
filling the void and making a solid floor? If so, a few questions:

It is a possibility, although it probably a more expensive and messier
option.

1. What would I fill the void with?

Concrete, damp proof membrane, insulation, screed and plastic pipe.

2. Would there be a consequence of the weight of the material I use as
infill?

Possibly. You need to have someone look at it with regards to the
foundations, although it is unlikely that there will be issues.

3. How much is this likely to cost?

A reasonable amount.

or does anyone have any other ideas?

Just underfloor heat the existing floor.

Christian.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Ben R"
saying something like:

I've just bought a 1950's bungalow and would like to install a wet
underfloor heating system. The floor construction is suspended
floorboards. Under these there is a void approx 50cm deep. The total
area of floor is about 90sq metres.

I understand that fitting underfloor heating to a suspended floor can
be problematic in terms of installation and efficiency.

You can get a type of ally channel with two grooves in for running the
ufh pipe. Under the channels is a layer of approx 4~5" of rockwool. The
channels are simply nailed to the joists and the pipes laid in the
grooves then floored over.

This system works well and doesn't have a large thermal inertia. Made in
Germany, iirc, but not too cheap. Having said that 60sqm cost me
~1500Euros in materials some 4 years ago, including manifolds, pump,
etc.
--

Dave

Grimly Curmudgeon wrote:
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Ben R"
saying something like:

I've just bought a 1950's bungalow and would like to install a wet
underfloor heating system. The floor construction is suspended
floorboards. Under these there is a void approx 50cm deep. The total
area of floor is about 90sq metres.

I understand that fitting underfloor heating to a suspended floor can
be problematic in terms of installation and efficiency.

You can get a type of ally channel with two grooves in for running the
ufh pipe. Under the channels is a layer of approx 4~5" of rockwool. The
channels are simply nailed to the joists and the pipes laid in the
grooves then floored over.

This system works well and doesn't have a large thermal inertia. Made in
Germany, iirc, but not too cheap. Having said that 60sqm cost me
~1500Euros in materials some 4 years ago, including manifolds, pump,
etc.

Have a look at www.polyplumb.co.uk

They do underfloor insulated trays for pipes. It ISN'T cheap, but its
quick. If you have the time, make up your own. All its about is stopping
heat going downwards.