Dr. Tim Padfield is a world renown specialist in museum environments says this about moisture content in materials...
"...the water content of materials depends mainly on relative humidity and is largely unaffected by temperature."
Dr. Tim Padfield
Professional Engineer, ASHRAE author and expert in the field of humidity control, Donald P. Gatley, P.E. provides these words...
equilibrium moisture content of materials is almost solely dependant on relative humidity and is
largely unaffected by temperature."
The Wood Flooring Manufacturers Association says...
(photo credits NRDC)
Learn More (be patient with this link, large file)
Radiant & Wide Plank Floors
Flooring Ltd. v. MacLeod, 2012 NSSM 25
Last but not least - the final word.
Part III : Our Favourite Reference Book on Wood and Wood Flooring
support visit our
visitor services page.
As visitors and contributors to www.healthyheating.com know, we do our best to dispel myths or what we call inoculating against viruses. We have not decided yet which of the following is worse, believing that
reflective bubble foil insulation under a heated slab is equal to the performance of XPS/EPS insulation or radiant heating causes hardwood floors to crack
or perhaps its the ignorance over
radiant cooling and condensation.
To prevent catching a bad information virus on radiant and wood floors lets establish that wood is a hygroscopic material which means its' dimensional stability is a function of its' moisture content which is influenced by the humidity changes in a space regardless of the heating system. All
the facts are explained in the Wood Handbook published by U.S. Department of Agriculture, Forest Service, Forest Products Laboratory.
Excerpt: "In the living tree, wood contains large quantities of water. As green wood dries, most of the water is removed. The moisture remaining in the wood tends to come to equilibrium with the relative humidity of the surrounding air.
Correct drying, handling, and storage of wood will minimize moisture content changes that might occur after drying when the wood is in service and such changes are undesirable. If moisture content is controlled within reasonable limits by such methods, major problems from dimensional changes
can usually be avoided."
Refer to Chapter 12 to combat the radiant causes hardwood floors to crack virus...and remind those who continue to spread the bad information that exactly 100%
of all hardwood floor complaints in homes heated exclusively with hot air - did not have radiant floor heating to blame.
"Dry wood undergoes small changes in dimension with normal changes in relative humidity. More humid air will cause slight swelling, and drier air will cause slight shrinkage."
"Flooring is usually dried to the moisture content expected in
service so that shrinking and swelling are minimized and
buckling or large gaps between boards do not occur."
Our comments: If the moisture in the home is not controlled to the RH% expected by the wood supplier, then home owners must expect dimension changes regardless of the heating system. Learn more.
The fine folks at Forest Products Laboratory make the entire book available online in a .pdf file to anyone at no charge - that's right! The online version is free of charge and full of facts. In our not so humble opinion, this is the best
deal in town. Hard copies can be purchased
Suggested reading for consumers and office
How to "ball
park" your budget for indoor climate control.
Built to code: What does it mean for
consumer thermal comfort?
Indoor environments: Self assessment
Comfort: A 40 grit perspective for consumers
Comfort System - The "Un-minimum" System
Comfort: A Condition of Mind
Do-It-Yourself HVAC - Should you do it?
The Cost of HVAC Systems -
Are You Paying Too Much for Downgrades?
Radiant Installations - The Good, Bad and Ugly
Thermal Comfort Surveys - Post Occupancy, Part 1
Thermal Comfort Surveys - Post Occupancy, Part II
support visit our
visitor services page.