Heating difference of hardwood and tile over heated slab
dfvellone
| Posted in General Questions on
I’ve experienced the difference in feel when walking on hardwood flooring and tiles laid on a heated slab (the tiles feel warmer on your feet), but I wonder if there is much if any measurable difference in the heating performance each flooring system. The hardwood would be installed directly on sleepers.
Thanks, Daniel
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Daniel, heat moves at different rates through wood and tile; the speed is described by their U-factors. (Or the inverse, the resistance to heat flow, the R-value.) Ceramic tile is more than 10 times more conductive to heat flow than hardwood, so the heat moves through it more quickly. But given time, and enough insulation below the heat pipes, the wood floor will transmit essentially the same amount of heat as tile.
You will lose more heat to the ground with wood flooring than with tile flooring, but with insulation below the heating pipes the difference won't be noticeable.
Daniel,
I will trust you looked into and are aware of the warranty restrictions for some wood floors over radiant heat. Some solid wood flooring materials do not respond well to the cycling over seasons from radiant heat. I do wonder how the sleepers will be put down. Do you know exactly where the tubing or wires are? How deep a fastener can safely go? Will the sleepers be deep enough to accept the flooring fasteners without them hitting the slab? Do you anticipate a lot of humidity variation over the heating/non-heating seasons?
I worked on a house with both tile and floating wide plank engineered wood flooring. However, the floor temperatures were being driven very high (95) due to the generally poor insulation in a 50's era house. Being in direct contact with the slab, the wood felt very warm to sock feet, the tile ridiculously so. Assuming your new home is much better insulated, your slab temps should even out at much lower temps to suit actual heat loads, which may give the wood an edge over tiles for thermal comfort.
The wood will not draw the heat out of your feet the way tile does thanks to the same point Michael makes, wood is less conductive than tile. Since you will likely not need the slab to go over 75-76 even in dead of winter, the highest tile temp will still be several degrees below the magic "toasty toes" figure of approximately 84F. Especially during low heat load parts of the year, the wood floor should still be perceived as "warmer" than the tile because it transfers heat less quickly.
If you are anticipating warm to feet tile, hopefully you are expecting that only in very small areas like bathrooms for short periods of use.