On 21 Feb, 12:26, wrote:
Hi,

I have just completed a large extension (approx 50m2) and installed
hot water underfloor heating. *I have partially tiled it but my better
half now wants to install Parquet wood block flooring over the
remaining 30m2, to match the rest of the house.

I have my reservaitions about expansion and warping with the heat
variations and have heard of complications with moisture content etc.
I am keen to lay it but dont want to come home to find speed bumps in
my living room. *I cant find any info on the internet about this, any
ideas? *I know that engineered boards would be far more suitable but
I'm told that matching it up is a must!!!

Also, does anyone know of any good suppliers of new (not reclaimed)
hardwood block flooring? *I have been dealing withwww.woodenflooringsupplies.co.uk,
who's prices start at a v reasonable £15-20pm2 for european oak, but
their service is absolutely shocking. *I've been trying to get samples
from them for weeks, completely incompetant.

Any advice greatly apreciated.
SPC

Dear SPC
I would work out carefully from the thickness and species of the
woodblocks just how much heat you are going to stop from coming up
into the room. Data do exist for such calculations so it should not be
difficult to google. Basically the denser the timber the more likely
it is to retain heat and not let it through. Once you have found the
ideal thickness and species with which you are satisfied the next
problem will be to ensure that they are equilibrated to the same mc
that it is likely to be in situ. This can be calculated by determining
the likely temperature and RH and hence the projected mc.

Next will be the problem of how to fix them in a suitable medium that
will stick it down and still transfer heat AND allow for some
movement.when moisture contents vary.
All in all some pretty careful assessment and design will need to be
done if you are to have both a structurally sound floor and heat
transfer. Much depends on your Delta T - my water circulates at 33/34
so is not very hot and so I need to have as little insulation from
carpets and wood as practical. A higher difference will be more
tolerant of thicker timber. Have you considered parquet as opposed to
blocks?

Regardless, I would get SWIMBO to sign a disclaimer as I share your
concern at her ideas and would go for a tiled floor myself!
Chris