A reply from the industry regarding floor plates vs no plates

Dave Yates (PAH)

Before I post this reply from a gentleman whose opinion I greatly respect, I want to interject my personal experience with plates vs no plates and 180 degree temps on zero degree days.

When we built our home, I (unfortunately) allowed a supply house salesman to hoodwink me regarding a number of radiant products and sizing issues. One of them was the plate issues. I did not use any.

As a result, I must run 160-180 degrees F on bitter cold days for all of my second floor staple-up. The home was saturated during construction. My floors pop and squeek like crazy during the heating season and are as quiet as a church mouse in summer. It's not the heat so much as it was the rain that set up this scenario (my beliefs). I will one day rectify this by abandoning the underfloor system and installing a surface product such as QuikTrak or SubRay.

Some ceramic & lots of carpet.

Here's the e-mail I recieved.

I have been watching Dan Holohans sight and have been particularly
interested in the discussion over joist heating. I will not get into the
plates vs clips debate right now. The point that I wish to address here
is in regard to plywood and TGI products.
I have been doing lots of reasearch as to the potential effects of
radiant floor heating on plywood or other laminated products. I have
talked with several manufacturers and with several manufacturers
associations about this topic. I have baked, burned, and soaked several
types of laminated products. (My wife is real pleased over this use of
our oven.) The overwhelming consensous is that RFH and laminated
products are a non-issue. Plywood and all of the other laminated
products that I could find use a heat cured resin and all of the resins
used have a higher cure temperature than we can achieve, even with a run
away system. The products will not fail until the glue reaches ignition
point which is very near the ignition point of the wood, about 700
degrees.
The issue that can occur with any wood product and with any type of
system is excessive drying. Wood needs moisture to retain it's strength.
6 to 8% is the normal range and this is also an acceptable range for
hardwood applications. Water is also an issue. Most homes get rained on
at least once during the construction process. It is important to
properly dry out the structure before applying the finished floors and
also to keep the plywood in tact. Hope this helps.



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Bill Clinton

pops and squeaks

could be from the tube. We are just fighting our way out of a noise problem with suspended tube. After doing many problem free jobs with non-barrier pex, we moved up to barrier. Better job, I thought. All those non-barrier jobs were quiet as could be: the barrier jobs would make you think you were living in a bowl of Rice Crispies.

Turns out that EVOH barrier is much stickier than plain pex. We had grown accustomed to allowing two or more loops of tube to lay hard against one another, therefore rubbing during thermal expansion. We did this with no problems.

With barrier pex, rubbing can be a noise problem and is henceforth a no-no around here.

Bill