One of the flooring advertisers on this site carries Junckers Hardwood flooring products. Does anyone have this product in their home? I would be interested in feedback.
The interesting thing about this is that it is a "tongue and groove" clip together. There is no adhesive that is adversely affected by any moisture that may come off the floor. The floor floats and is approved for radiant heat (which I still have in the floor). It's a very beautiful floor and looks very modern. Since it's snap together, the flooring person said that Europeans often bring their floor with them when they sell their house - interesting.
I'm still considering going with tile or stone since it's the best engineering choice but the look and softness of the wood (compared with the tile) is so tempting.
It would be interesting to hear from someone who has real experience with hardwood and radiant heat.
In my mind, I just do not see how a floating hardwood floor would be a good conductor of heat. First, the floor floats on some sort of pad, so there is air space between the slab and the wood floor. Next, there is the wood floor itself, and I do not see that wood is a very good conductor of heat.
I always think of a pan on a stove. If the pan has a metal handle, you would not touch it because it will be hot. But, a pan with a wood handle, not a problem, because the wood does not get hot.
I am by no means a scientist, but I did locate a chart that shows the thermal conductivity of various materials.
The thermal conductivity of wood, for example, is rather low (.13), while the conductivity of granite is higher (2.1).
An interesting subject, and it would be great to hear of some real world experiences.
We elected to go with a limestone tile. This will be our first winter with the new floor. We previously had carpeting and froze. With the cooler temperatures thus far, we have been quite comfortable with the heat coming through the tiles.
You are correct. Wood is not a good conductor of heat, as the numbers you provided clearly show. On a percentage basis, the difference btw conductivity of wood and granite is huge.
In conducting research for some articles on kitchen remodeling, many of the designers and experts I interviewed indicated that the lack of conductivity did NOT mean that the floor would't get warm, it just meant that the transfer rate would be slower. It would take longer to heat up and to cool off.
I would have greater concern about woods abilty to handle the temperature swings caused by the radiant heat (i.e., constantly expanding and contracting)--does this create the potential for drying and cracking later? Or worse, squeaking? Also, there is the whole moisture problem. You will likely need a moisture barrier installed, but what happens to your beautiful wood floor if a pipe bursts?
Aesthetically, I have seen pictures of wood floors in Eichlers and they can look quite nice, but I have never actually been in one-- they are not that common, from what I have seen.
We just recently (last month) purchased an Eichler home that had a Junckers oak floor installed in it by the previous owner. The style of the floor is not completely to my liking (it has knots and heavy grain, the 'rustic' look) but otherwise the installation and appearance of wood in the eichler looks very nice. I can't comment on heating efficiency through the floor, however. The old steel radiant system leaked and so we have just finished a baseboard retrofit. The hardwood flooring shows a slight warping/cupping in some areas that are likely due to the old radiant heating or radiant heating leakage.
The floor is floating and very quiet.
Lynn: there has been a ton of discussion on this site about hardwood floors and radiant systems. Stay away from hardwood, especially the kind that "clip" together. Most likely, is will float over your slab. By floating the wood flooring, it will create a vapor barrier, which will kill a large percentage of heat rising through the slab. This is similar as a vapor barrier between two pains of glass in a double glazed window. This is an issue for any substrate not glued down (cork, carpet, laminant flooring).
You are also asking for big problems if you spring a leak in your radiant panel.
If you're looking for softness and still want your radiant heat to be effective, consider looking at Armstrong VCT tiles (Imperial Texture patterns are the same as the asphalt tiles originally used in Eichlers) or a glued-down cork. From there, I would look at commercial tiles (like dal-tile) for some clean, simple colors.
I would also stay away from hardwood while the radiant heat is still working. We made very good experience with engineered hardwood floating on the slab, but again our heating was already converted to forced air by the previous owners.
If you really fell in love with the hardwood look, Pergo floors would be a sensible alternative since they are glued to the floor and are only a minimal heat barrier.
To my knowledge, Pergo is also almost always installed floating. However, the Pergo material has better heat transfer and heat expansion is less than with machined woodflooring, such as Junckers.
I think it is quite simple; I have a friend who have Junckers floors and they are very happy with it. It gives a more natural, softer feeling than Pergo. If saving $40/month on the gas bill during three winter months is more important than the looks (or if your system can't get house warm enough), go for tile/natural stone instead (or get a new boiler).
Thanks for all the information. I think the R-value of the wood is important but it doesn't take into account the air gap - basically the fact that the wood is not in direct contact with the heating source. Adding the felt and a waterproof layer only makes it worse. It sure is beautiful though.
The radiant heat certainly has benefits but it's a bit frustrating being so limited with respect to flooring materials. Newer concrete floors with radiant pipes are much more reliable than our older slabs. You don't need to worry so much about leaking as our old slab pipes do occasionally.
Sounds like it's slate or tile and I will use throw rugs to give it a softer feel where appropriate. Thanks again for the feedback.
Lynn in Palo Alto
P.S. to Cathye...I too am starting to collect lots and lots of tile samples! So much to choose from.
There is another option available today for heating your floors and entire home. It is based on a newly developed technology that uses a thin film, impregnated with electronics (I am not describing it very well) and heats via low voltage. The heat transfer is supposed to be very high, since it has a high surface area, as opposed to traditional radiant systems, which have pipes that are spread wide apart. As a result, efficiently heats your floors without getting hot (thus reducing the concern about laying hardwood over it). It is also designed as a "sole source heating system" - as opposed to some of the other products that are designed for auxillary heat, say in a master bath. Also, with this system, you can do your whole house, or just one room, and adding on is simple. The energy efficiency statistics are astounding. From what I have heard, an entire house can be heated for around $600 per year.
The product is called warm floor and Franz Rogman, an advertiser on this site, has just started using it. So far, he has installed it in several Eichlers. Go to http://www.warmfloor.com and take a look.
I wish I had known about this product BEFORE we tiled our entire house, but it is very new on the market.