I am rather new to this whole ICF concept but am considering it for a home we will be building in the near future. The jist of what I'm reading seems to suggest that radiant floors are the most logical forms of heating for concrete homes. I need hardwood floors in my home. I will have some ceramic or such, but most of my flooring needs to be hw. We don't want any floating floors, so, I guess my question is: am I out of luck? Can hardwood be at all installed over radiant floors?

Well, I don't know about that! Other forms of heating should also work well.


Absolutely. It's very common.

no problems useing real hardwood just make sure you design your system for that type of flooring you will need to run lower water temps for the wood

It just seems odd to me, coming from a woodworking frame of mind, that i could heat a layer of hardwood enough to heat 8 or 9 feet of air above it, and not compromise it's structural integrity. Am I not begging that wood to shrink and check, etc? Are we talking about engineered hardwood?

http://www.greenbuildingtalk.com/Forums/tabid/53/forumid/12/postid/29405/view/topic/Default.aspx


I think this post might help you regarding wooden floors with radiant heat under it. 

Yes, it works great 9' above. I can attest to this.

Ibeams are a dream otherwise its a bitch. Right angle drilling (no clutch) can crack your head and teeth if you hit a nail/knot. Can't say it happened to me ..yet. I have seen the aftermath. "POW right in the kisser!" 

Ahh .... New homes don't have this problem right?

Mikeinnyc

Or, depending on your cost per kilowatt hr for electricity, you can use a low voltage element directly under the wood. There's no floor buildup or maintenance and, just like with hydronics, you can nail through it anywhere on the grid...except it won't hurt the element! ;)

In any case, don't forget the heat loss calculation and some form of humidifaction to maintain the moisture content of the wood.

you need to have proper humidity in your home for the hardwwod it should be 35-55% rh to help prevent checking the hardwood should also be recessed cut on the backside to allow for some exspansion

When you talk about 'lowering the temp', I'm assuming it will still be warm enough to heat the room? Also, while we are on the topic, I'm always taking my socks off because my feet are hot...... can't even go near wearing slippers; will a heated floor drive me crazy?

All I can tell you is this... I installed radiant floors in my 200 year old farmhouse and they are probably my wifes favorite part of the whole house. We have almost 100% wood floors in the house and love it. In the places we desire carpet we simply put an area rug down. It works for us. I tore the ceiling out of my first floor, my wife hand formed aluminum plates and I installed 5000 feet of pex, 2500 feet of radiant barrier, and 2500 fiberglass insulation for this system. Four years later I would do it all again. I just want an alternative fuel source for my boiler.

I'm just guessing, but what you might have to do if you lower the temperature is to run more loops of PEX than you would with another floor covering, or your heating system would cycle on and off less frequently to get the same air temperature.

running more pex lowers the water temperature you need to achieve a given floor surface temp.

the floor surface temp you need to achieve is determined by your heat loss, and heat loss only. This is a number somewhere between room temp and 85 degrees for wood floors, typically, and your output is roughly 2 BTUs/sq ft per degree the floor is higher than room temp. so if you want a 70 degree room, and 85 degrees is the max surface temp (claimed by some wood MFGs.. not sure how they handle sunny days, but hey, I'm not a wood guy..) you can get 30 BTU/sq ft out of it IF you radiant method can get the floor up that warm (which isn't as easy as you think).