Proper design and layout is important with radiant floor heat, especially to end up with an efficient and comfortable installation. Additional precautions and sometimes extra measures must be taken to accommodate radiant systems such as heat spreading installation techniques which may be aluminum heat plates or "warm board" type systems. This is especially true when wood floors are done. In addition on occasion an additional heat producing supplement may be needed to meet the heat loss requirements of the space when the floor temps and usable areas are limited. I do not recommend going any higher than 85 degrees on your wood floor surface, or 88 on tile products. This maximum floor temp is accomplished by mixing valves, injection pumps or motorized 3 or 4-way valves, many times with floor sensors. Humidity level of at least 40% is required in the colder months when the floors are constantly kept at 85 degrees. Past experiences of mine has been that even with prefinished floors, an extra coat or two of polyurethane is needed to seal up the cracks. Also, without a lot of rugs, which hampers the heat transmission, the tile in the kitchen is way more durable for the heavy traffic and abuse a floor in a kitchen can receive. IMO

Thanks for all of the replies. I'll give some more background info. The first layer is the existing subfloor which is real wood, it looks like a 2x4, but the size is actually about 3/4" x 3.5". The subfloor has 1/4" or so gaps between each board. The second layer on top of the subfloor is the existing wood floor, which is real wood. It looks like oak and must be regular cut, but not entirely sure. It has alternating widths of about 3/4" x 3" and 3/4" x 5". It currently has some gaps between most boards about 1/8" or so wide. We plan to install real wood flooring on top of that, but not sure what species yet. Are there certain species that won't work? It sounds like I may have to get a certain type of cut. Do you think it will be okay to install the new wood floor over the existing wood floor, or is the old wood floor likely to buckle underneath if it expands too much?

Hola, Sorry, forgot to post layout: And no, we're not thinking of using our huge fireplace as a heat source. My kids have asthma, so all the tiny particles from wood burning or pellet stoves are not good for the kids. And I don't think they're that environmentally friendly. If we have the money, we would do geothermal heating. Here's our house in about 20inches of snow last year (does this help your decision, since it's nice and warm today?): plllog: "You have young children. You have a budget...Then the children can spread out their painting projects on the floor, roller skate, or whatever. Real linoleum, such as Marmoleum, is an ecologically friendly choice...you can easily replace it when you decide you want hardwood. In fact, you can do the subfloor as if you're getting hardwood... Then it's easy to mop. And you can make the change when the kids are older and you feel like spending the money--or not." These are my thoughts exactly!!! roobear: "Hardwood is better for resale, it would add value to your home, it can be refinished etc. Plus, it would fit the period and style of the house better." EXACTLY! The flip-side of my thinking as well. If I'm going to do hardwoods later, why not do them now and enjoy the benefit of the flooring, rather than pay twice? I've also thought about the heated rugs; the Japanese use them all over their house. circuspeanut: "have cold feet 6 months out of the year" Argh: sometimes it feels longer. cleo: "using engineered hardwood floors" Great idea, but because we installed some in our previous house, I really did not like them. My main concern w/ them is wear and tear, especially in between the planks. What happens if water (or raw meat juice) gets in between and swells the ?particle boards, etc? lovilynne: "have you considered DIY wood" Oh, while my house is not historical, it seems like it with the uneven floor, no insulation in the walls, etc :) We are DIY the hardwood floors for the 2nd floor right now. The learning curve was HUGE for us. And I'm not sure about my skills w/ hardwood floor over radiant heat. "they make a special heater to go under the cabinet" Oh!!! Can you please tell me more? Do you have pictures to share? Hmmm...

The original kitchen had linoleum, and while planning our reno we debated between hardwood, laminate or porcelain tile. I hate having hot feet, so radiant heating has never been a consideration. I live in southwest British Columbia, so it doesn't get too cold, and our forced air ducting runs in the crawlspace beneath the kitchen, so the floors don't get that cold regardless.. Anyways, hubby, the kids love the ice machine in our fridge, and they are always dropping crushed ice. The kids are always having spills and the floor almost always has at least a drip of water here or there. It's a well used kitchen! Because of my concern about water, we ended up installing porcelain tiles. I have always been aware that I should wear shoes in the house because I have a mild foot deformity that is at risk of worsening without appropriate support, but I've always gone barefoot in my home. The tile changed that, my feet become painful if I don't wear my house slides if I'm spending the day baking, but I suppose it's a good thing for me to support my feet. Hubby has dealt with plantar fasciitis prior to changing the floor, so he always wears house shoes as well. We haven't noticed any pain in our hips or knees, but we are still quite young, and I'm sure wearing shoes helps with our alignment. Right after we installed our dishwasher on the new flooring, there was a big leak, and I'm glad I went with the tile! It's easy clean, I don't stress about the kids sliding their chairs and stools across it, and it's an attractive tile. I prefer the warmth of wood, but I know for our family, tile was the best choice, and we are willing to wear house shoes. I've brought wood into the kitchen in different ways, with the stools, utensil "pots", cutting boards, etc.. There will always be pros and cons, you just need to decide which has the least cons and the best pros for your situation :). Also, when you are considering cost, find out if you need to install subfloor. We ended up having to install ditra, which definitely added to the cost. Good luck making your decision.