Radiant tubing under a subfloor

In my previous post, I described installing hardwood tongue and groove flooring directly to 3x3 floor joists on 12" centers... thereby forgoing the typical plywood subfloor. Based on our first experiment (and 200+ years of historical precedence), it looks like that will work just fine. The brand new floors squeak a little bit, but I think I can solve that in the other areas with a shot of Liquid Nails between the flooring and the floor joists.

Where we'll be installing tile, slate, or stone floors, we'll need a typical subfloor - I just don't see any way around it. This first picture is the subfloor for the foyer and master bath. I chose 3/4" t&g plywood instead of 3/4" t&g OSB. Although Advantech (tm) OSB has a 50 year warranty, I feel that plywood is the lesser of the two evils. On top of this plywood, we'll install Hardibacker brand cement backer board before installing the actual flooring material. Never having done this before, I'll be using guidelines found in books and the internet. If anyone has any tile installation advice, please post now! :)

The last step before installing the subfloor is installing the 1/2" radiant heat tubing. Technically, we could install the radiant heat tubing from below, after the subfloors go down, but it seems to be a lot easier to pre-install it from above. My brother-in-law is using his router to cut channels in the floor joists wherever the radiant tubing must cross the 3x3's. Per the instructions on radiant heat web sites (google radiant heat if you're interested), I'm installing about 1 linear foot of tubing per square foot of floor space. The tubing costs about 40 cents per running foot. I'm trying to keep all of the loops about 200 feet in length. If you make the lengths too long, the water will be harder to pump, and will give up all of its useful heat before reaching the end of the loops. We've been careful to mark the "NO NAIL" regions of the subfloor because we don't want to poke a nail through the radiant tubing after it's all been installed!

The last picture shows the tubing beneath the kitchen, just before we installed the subfloor. Here, I used store bought fir 2x4's on edge instead of home-cut oak 3x3's. Using store bought lumber was a shortcut that cost me more money, but also helped to solve the problem of leveling the transition between adjoining tile floors and hardwood floors. BTW, if 2x4's and 3x3's sound like wimpy floor joists, keep in mind they are spanning less than 4 feet and are on 1 foot centers. After installing the plywood subfloor, this floor system has zero noticeable bounce or deflection. (Hear that Uncle Jeff? I know this has been keeping you up at night!)

Later, we'll go back in the basement and tack the radiant tubing up to the subfloor and hardwood floors with highly conductive aluminum brackets. Keeping all of the tubing in place so we can nail the subfloor down is has been somewhat of a chore. The tubing has a spring-like shape memory and wants to coil back up like it was shipped from the factory. Beware - it will reach out and smack you or trip you whenever it gets the opportunity. We have learned the hard way!

Cheap hardwood floors in the concept room

I found some really affordable hardwood flooring at a local lumber yard. In fact, these 1x6 yellow poplar tongue and groove planks are so cheap, I can't really see how they afford to make them, but that's not my problem. Whereas most of the wood in our house (and all of the timber frame) is from our farm and cut on my sawmill, I am becoming very rational about trying to finish this house. When I can buy something for cheaper and better than what I can make it, then I'll buy it. The flooring is 50 cents a linear foot, which works out to be a little over $1/square foot (the 6" boards actually only cover 5.2" in width). What's even better, these are random length, with the average length being 12 feet!!!

As in these pictures, much of my house will have no plywood subfloor. Instead I plan to install hardwood flooring directly to oak 3x3's that were cut on my sawmill. The advantage of this is that I'll save about $2000 in not buying plywood, and reduce the amount of resins and glues in my house. (I'll take solid wood over plywood any day, because among other things, plywood burns so much more readily) The drawback to this flooring is that it is (yellow) poplar, not oak, which means it is not as hard. My wife and I rationalized using it in low traffic areas (kids bedrooms and closets), and resolved that if it doesn't work out, we can floor over this flooring in a few years and it will become the subfloor! (per foot, the hardwood floors are only about 40% more than 3/4 plywood itself!)

The pictures shown here are of back-to-back walkin closets that connect my two sons' rooms. We call this large closet our "concept room" because we're trying out our floor and ceiling concepts in the closet to see if we like them. If we don't like the finished result, well, it's a closet and no one will care too much. So far, we like the result - it looks like poplar floors are a go!

Dry wall in the tower and great room

It's been a while, so I thought I'd post this just to let folks know that we are alive and kicking... and still working on the house. Most days are spent hanging drywall. It is slow going, especially when the dry wall has to be trimmed to fit in spaces between the timbers, or when working from scaffolding 20 to 30 feet in the air. We're getting there though. Although most of the electrical wiring is done, we haven't started on the plumbing, so some of the interior walls will just have to wait. I definitely plan to hire a professional to "mud and tape" the drywall after we finish hanging all of it.

My oldest son's room, located on the second floor of the tower:

A picture from the great room loft - the pink lines are strings that will guide the construction of our chimney (in a year or two?!):

Top floor of the tower. Piecing in drywall around the windows and braces is sometimes tedious:

Cool angle of the hammer beam from the second floor balcony. Only the scaffolding betrays the fact that this is not a finished house! (I'm allowed to dream though, aren't I?!)