Hello everyone,

My first post here. Last year I purchased a fixer-upper, my first home. Although it needed (still does!) a lot of work, it was very obvious from day one that the heating system needed to be replaced ASAP (20+ year old forced air system). I knew that I wanted radiant and opted for a staple-up installation. My house is about 1400 square feet with all living space on the second floor. The ground floor is my garage and a large unfinished basement with ceiling heights from 5 to 10 feet. This is one of the reasons I went with staple-up. It was easy to install. I had considered Warmboard, but was talked out of it by the company who installed the heating system. While they like the product, they think it's too expensive. Furthermore, they didn't think I needed it.

To be fair, I didn't get all of the floor insulated (3" thick R-MAX) last winter and I know that the rest of my house isn't the most energy efficient. I still have to replace the insulation in the exterior walls, re-insulate the attic, replace the roof and siding, and add new windows. My gas bills last winter averaged $350. OUCH! That seems nothing short of absurd to me for a 1400 square foot house. Oh yeah, I'm at Lake Tahoe, so we tend to have mild winter days with lots of sunshine and very cold nights.

I need to finish insulating the floor. I know that. But is there anything else I can do to improve efficiency and lower my costs? Would it be worth considering installing Warmboard now? I haven't put down my finished flooring, so it wouldn't be difficult to add Warmboard. I'd have to bring the Pex into the house from underneath, but I can't imagine that's very difficult. Would I see a dramatic improvement in efficiency if I did that? Is it worth it? Or total overkill?

What other options are there? Is there a way to draw more heat out of the tubes than those flimsy little aluminum plates? Any way to hold the heat longer?

Even with good cuts, the R-MAX insulation leaves gaps. My joists aren't exactly perfect and there are all kinds of little corners and places where existing electrical wiring, pipes, etc. prevent me from getting a nice tight fit with the R-MAX. Is it possible, after installing R-MAX, to spray some type of expanding foam insulation onto the R-MAX sheets and floor joists (there's about 2" of floor joist showing after installing the R-MAX) to seal up all the nooks and crannies, trap heat, and prevent bugs from getting between the subfloor and the R-MAX? Or should I ditch R-MAX in favor of a better product? I've seen some references to MicroFoil on here and it sounds very interesting. I'm sure I can eBay the R-MAX...

FYI, the house has a 3/4" plywood subfloor throughout, to which we added a 3/8" top sheet to tighten things up. I plan to put down hardwood in all living/sleeping spaces and tile in the kitchen and bathrooms.

Finally, I see a lot of references to some type of "vapor barrier" when installing radiant flooring. Does this apply in a staple-up system? Currently my Pex is stapled directly to the subfloor with aluminum sheets and the R-MAX is pushed up against this.

Any and all advice is much appreciated!

-Rob

I would concentrate on figuring out why my heating costs are so high prior to deciding a course of action. Some things to consider:

• Is the heating system installed in an inefficient manner?
• Do you have an inefficient heat source(usually a boiler)?
• Have you had a Heat Loss calculation performed?
• Is your Air Infiltration rate High?
• What size pex are you using and it's spacing?

I really wouldn't try to solve a problem until I knew what the cause of the problem really was.

Fair enough. I think the big cause of my problem is 1970s construction in Tahoe. A $350 gas bill for a 1300 square foot home seems excessive, whatever the reason.

I don't know how much it cost to heat the home before I bought it. The former tenant was quite cheap and kept the house at 60 degrees, so even knowing his gas bills doesn't tell me much. My windows are old aluminum sliders and they're always very cold. I'm sure the exterior insulation has a meager R value. It's probably original.

My radiant system is brand new. The boiler is a Munchkin. My floors are on 16" centers and the plumber ran 2 tubes per joist. I believe the tubes are 1/2", but I'd need to dig up the paperwork to confirm (or go measure). The company that installed the system is one of the most reputable, if not the most, in the area. They weren't the cheapest, but they do a lot of the big new homes, the ski village, etc. here so I figured (and still believe) they know what they're doing.

Until I re-insulate the walls and replace the windows, for starters, I know my bills will remain high. I'm in the midst of this remodel (living in the house) and, quite frankly, am in over my head a bit. I feel like I made a few less than educated decisions early on.

What I'm hoping to do now is bring this thing to a conclusion. One of the areas in which I feel less than educated is heating. I knew I wanted radiant and received so many different opinions about how best to incorporate it into my remodel. Had the existing heating system worked remotely well, I would have waited, but winter was coming and I needed heat. When I evaluated all of the different installation methods, staple-up proved the easiest.

I'm prepared to not have the *most* efficient heating system. However, I'm at a point now where I need to make some decisions and bring all of this to an end. I want to put down flooring throughout the house. I've weighed the cost of adding Warmboard, for example, and bringing the radiant tubes on top of the subfloor, with ever-increasing heating bills. Assuming new windows, new exterior insulation, etc., would having the radiant source inside the house, pushing heat through a 1/2" piece of engineered wood versus 1 1/4" of subfloor and 1/2" of engineered wood, give me a dramatic increase in efficiency? Does the Warmboard draw out that much more heat?

Is there a better way to insulate the floor and seal up all the nooks and crannies than R-MAX? I like the concept of Microfoil, and the fact that it adheres to the joists. How well does it work? Would it increase efficiency to put this product down first, then stuff the R-MAX into place?

I'm not asking for anyone here to solve my problems. And I won't be able to figure out why my costs are so high until after I finish all of the other work. I'd rather not wait that long to address my floors. The way I see it, I have a well-installed staple-up system and I want to make it more efficient and I'm willing to incur some expense to do so. I'm just trying to figure out what's worth exploring and what isn't.

I would install an efficient outdoor gasification E 3400 wood furnace.  burn wood, a renewable resource. Call me and I can get one shipped to you. call 877 904 8424

I think you need to spend the money on insulation and stopping air infiltration.  Spending money to redo an already new system is a waste.

Take apart an outside wall and see what you have.  Put any extra money you have into increasing the insulation on those walls and roof.
Make sure you check for air flow in and around windows, doors and electrical outlets. Simple penny saving solutions will start to add up and every dollar you spend that way will cut the costs of heating.

Is the system performing from a comfort standpoint?  If so, it is not a capacity issue and the problem is heat loss and/or system inefficiency.  What are your supply and return water temperatures?

I agree that solving the insulation/air infiltration problems should be your first priority.  As heat rises, roof insulation is generally a higher priority than wall insualtion.

xexpat

"As heat rises, roof insulation is generally a higher priority than wall insualtion."

Actually as this is radiant heat, you want to start with the area close to the tubes. and move outwards. the area between the tubes and the outside wall with spray foam is a very good start. Add insulation under the tubes so all heat radiates upwards and then the walls and you will start the process well.

First, let me say it is definitely not economically worthwhile to rip out a radiant system to put in warmboard. While warmboard might help you achieve a more efficient system, it would never have payback in this situation. Adding heavier plates might help, if water temperature or "heat constipation" is a problem for your efficiency. What water temperatures are you running? What boiler are you using?

However, your fuel bills mean nothing until you are done insulating. Insulation is huge. Not having it is likewise huge.

Ignore radiant barrier insulation for the joists (I can't comment on the ceiling except to say that ceiling loss is fairly low, typically, with the levels of insulation we typically have in the ceiling in cold climates), and use real R value under the plates and seal up the ends of the joists.

Beyond that, you could get a thermal imaging camera out to look for deficiencies in your house envelope, which would be well worth the cost if they identify any major issues. I think Firefly Infrared is in CO.. not sure if they are near tahoe, but it would be worth checking.

I just installed a new hydronic system at my remodel also in Lake Tahoe. It uses the staple up tubes below the floorboard. My problem is the 'rice crispy sounds' that propagate when the system starts the heating process. Can anyone tell me if this the noises are due to the installation technique or would I get the same noises with Warmboard or Gyp-crete. Would the noise level be less if the water temp. was brought down from 135? Robbyx, can you tell me the name of your hydronics provider at Lake Tahoe? I need someone new to work with. Thanks, Rob

Thank you to everyone for your thoughts and feedback. Much appreciated. I was visiting family and they didn't have reliable Internet, so I'm just following up now.

I'm meeting with someone tomorrow about spray foam for the floor joists. I've been struggling to properly insulate the floor with RMAX, but it leaves too many little gaps, especially with my warped old floor joists. I'd like to sell it and use MicroFoil plus spray foam, but I may just have them spray from directly onto the RMAX once it's installed. I'll see what I they say. Any thoughts on using MicroFoil vs. RMAX in my situation. Is one going to reflect heat better than the other (when used in combination with spray foam)?

I also agree that I need to better insulate the house and that it will be impossible to truly gauge how efficient (or inefficient) my system is until all of that is finished. So I'm trying to focus my attention there right now. I don't think there's anything wrong with the equipment I bought. I went with a Munchkin boiler, since someone asked.

Also, to the guy in Lake Tahoe, I used Jack Rabbit Plumbing down in Minden. I think they also have an office in Carson City. As for the popping sound, mine does that too. Have you insulated your floor yet? I find that once the RMAX is shoved into place, the popping noise stops. The only spots I hear it are still without insulation. Maybe coincidence? But the other spots stopped making the noise once I insulated.

Thanks again to each of you for your thoughtful advice.

-Rob