Re: [GBlist]DIY radian floor heating

[Sacie H Lambertson <dlambert@grasshoppernet.com>]

Since a number of people have asked me about our specific experience with
DIY installation of radiant heat flooring, I'm going to answer publicaly.
	Via the people in Vermont who specialize in selling RFH material to the
DIYer, you can get full and complete advice on how to install the tubes in
the floor--in our case a concrete pour, advice on type of system, direct vs
indirect, and if you call several times more, hints about the easiest way
to handle the tubes.  Along with the advice, after you've paid for it, you
get all the tubing you will need, and all the bits and pieces you or a
plumber will need to hook up the system, including pumps.  They sell a
super expensive DHW heater, but of course you don't need to buy that.  I
didn't.  The booklet they send you is helpful but we still had to call with
questions.  There are several people on the 'tech' staff who are more
knowledgeable than others.  Those are the people you want to talk to.
After you've asked the obvious questions and still need to understand more,
call back to ask for the oldest most knowledgeable person.  They are very
friendly and not impatient.  I called probably half a dozen times.  As with
anything new, you will be anxious to do it right, and overly careful about
the instructions.
	There are no special tools required for installation, just a lot of
patience.  Although we/I am used to building, no special skill is required
to unwind the tubes (frankly the hardest part and here hints are useful)
and fastening them down.  (You can learn to 'tie' very quickly and it's
fun) We tied ours to a grid of #3 rebar (underneath the rebar so the tubes
had to be held down with concrete blocks until we got the rebar down).  It
took us about twice as long as we expected.  The rebar served a dual
purpose, ie useful for holding the tubes at the right place in the concrete
(in the middle) and it strengthens the slab, far superior to the standard
#6 mesh commonly used in slabs. 
	We put RFH in 2600 ft sq of flooring.  The cost for the material excluding
the DHW heater (ours is a direct system) was $3311.00.  A plumber is doing
the rest, although Radiantec assures you you can do it yourself.  I don't
trust my soldering skills.  We have used Pex throughout the house btw and
anyone can do that.  The supplies from Radiantec include everything you
need for the installation of RFH except the thermostats for the different
zones.  They will help you design the whole deal as well.  It is not rocket
science.
	There are specific suggestions that I would be happy to pass on to anyone
who actually is going to do this job themselves.  Assuredly it is not
difficult.   But read the EBN article first to make sure you know more
about the system.
	The article mentions that old Korean houses use this system.  But I can
tell you that modern houses over there have it too; furthermore I believe
it is the most prevalent heating system in that country.  Others are way
ahead of us in some things. 
	Our floor is 3" thick concrete sitting over 4" of EPS which rests on steel
joists over a full basement.   In the walkout portion of the basement where
the tubes are placed, the insulation is 4" of mineral wool with the
exterior concrete wall isolated from the concrete slab by a couple inches
of mineral wool-ie a thermal break.
					Sacie Lambertson

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