I am gearing up (finally) to build my dream home, and want to set the bar in the new subdivision that we are building in. I plan to build with ICF to the rafters, and I have been going back and forth with the idea of radiant heating. While researching I stumbled onto the Warmboard products, and like the idea. I am wondering if anyone is UNHAPPY with their product? Is the price still around $7/ft?

The absence of complaints after 4 days, despite the wide open door, should give you a good indication of the quality of the product. There may still be some complaints that surface after a little while, but when they do, dig deeper to see if the complaint is about the product or about the cost or some mismanaged expectation in the house building process.

It does what they say it does and they back the material with a good warranty.

Posted By Barry E. LaDuke on 11 Feb 2011 05:43 PM
The absence of complaints after 4 days, despite the wide open door, should give you a good indication of the quality of the product. There may still be some complaints that surface after a little while, but when they do, dig deeper to see if the complaint is about the product or about the cost or some mismanaged expectation in the house building process.

It does what they say it does and they back the material with a good warranty.

I don't know if the product is good or bad but if the quoted price is right I would prefer an 1.5" concrete overlay for the mass. My concrete cost me under 3.50 / foot to place and finish and my subfloor cost me .38 /sq. ft. Also as you put the product down as subfloor what happens if it rains or snows? When do you install the pipe? If you do it right away all the trades have to work over it. If you leave it to last the grooves will be full of wood chips from the electricians drill and mud from taping etc. As I said I have not used the product so these may not be issues but something to think about.

The original poster asked for input from someone who was "UNHAPPY with the product." Comparing the product to other methods is a different topic entirely. And your cost analysis for the slab is incomplete. There are many more variables to consider when pouring a 1 1/2" thick cement slab onto a joisted floor. Joist size, double-plating, moisture mitigation for off-gassing as the slab cures, etc. etc. etc. Floor covering costs are also going to be higher.

I'll let the Warmboard people defend their pricing as I am a former employee and it wouldn't be prudent to comment publicly about pricing as an outsider with insider knowledge. Plus, I sell a competing product. You might see my "Professionals serving in your area" link in the right sidebar (shameless plug) ------>

It was only my intent to put the concerns of the original poster at ease with regard to the integrity of the product itself, not its relative value compared to something else. I'm their competitor now and I'm telling you that the product is sound and the company is stellar. Certainly there are other ways to get radiant into the ICF house of the originating poster and many will be cheaper to install. If he chooses something other than Warmboard, it should NOT be because of concerns about product or company quality.

FBBP: Mass is your friend if you need it for STORING heat, but mass is horrible at TRANSPORTING heat. As the folks at Warmboard might say: "The purpose of a radiant panel is to conduct heat," not store it.

Water has a much better capacity to store heat than concrete, and water is portable. You want mass? Put in a large water storage tank. Then use solar or some other free/cheap method to gather heat when you don't need it and store it for later when you do need it. If you store it in a water tank, you can pump it to wherever you want, whenever you want, and only as much as you need for the moment.

PassivHaus exceptions apply if solar gain is properly managed using thermal mass.

also with the gyp comparison increase your tubing and manifold cost by 30 to 50% for tighter on centers. that's usually good for a buck a square foot or so. now you're pretty close to the same range as warmboard without a subfloor, and the warmboard will outperform the gyp and greatly simplify wood floor installation.

There are many other products and niches but the cost comparisons are tricky unless you take the whole assembly (and, in most cases, labor) into account.

other hawkers should note the level of integrity Barry just brought to the game. I wish all sales guys could handle themselves with such grace. kudos.

Barry - you are right, it is a different topic but closely related. My apologies if anyone felt it was to off topic. Normally GBT readers don't mind related topics. The price jumped out at me and I just wondered what the other benefits might be to justify the cost. You point out one. Mass is not always your friend. For me it is as in Calgary we have great temperature swings that mass tends to modulate. Concrete or Gyp. floors don't normally require huge increases in floor structure cost as they dampen the vibration of the span. I for one don't mind "shameless plugs" if the vendor is adding true knowledge to the forum. I find this quite different than those who make irrelevant post just to see their name in print. So as to my inquiries of how the trades handle the floor and when is the best time to install the pipe, your knowledge would be a great asset.

Rob - I used concrete @ 3.50. I believe my gyp price was more than 1.25 less which would certainly make up for the headers and such. I just don't like gypcrete that much. There is some advantage to wood floor over Warmboard type installs, however I would think that you would probably need more insulation under the floor to offset the thermal barrier of the hardwood. (but that's more your domain then mine so I won't try to teach Granny to suck eggs.) I like the concrete because I go with a concrete overlay for finished floor that looks like hardwood. My intent of the post was to try to understand the other benefits of the warm board that I felt I must be missing. And as a GC I just naturally look at what any product would do to my construction schedule.

you are doing uncovered concrete floors, you mean, with just a stylized finish? if so, it's pretty hard to beat that for performance, but finding concrete guys that can do that kind of work with confidence appears to be a struggle for most of my clients.

After Rob's very nice comment, I'm hesitant to say any more, but I also want to respond to FBBP: No harm, no foul. You weren't so much off-topic as I was trying to straddle a very precarious place atop this fence.

I have very specific comments regarding the cost differences between products, particularly the differences between WB and the one I carry, but we should go offline for that. The Canadian angle adds more cost complexity to your question as I'm not familiar with how a US-sourced panel product (mine or theirs) fares when border-crossing costs are factored in. With freight being calculated on weight, I know the overlay products will cost less to ship than WB.

As for the construction time frame, that is one of the key strengths of the argument for an after-subfloor approach - tubing goes in later and reduces many of the hassle factors associated with such an early installation. In fairness, though, I know WB will design tubing layouts with a late installation approach if you request it. You wind up either dealing with tubing in early with a strong suggestion that you protect it during construction, or empty grooves that need to be cleaned out if you wait to put tubing in later.

I've analyzed the over-pour cost arguments a-plenty over the last decade, and have taken the feedback of many GCs and carpenters regarding costs into account in my ciphering. As Rob notes, it is still very close to a wash. It then boils down to two important variables for a GC - hassle factor (still favors panels over concrete, in my view) and construction scheduling. Removing the concrete pour from the schedule does have its advantages. Compare the pour to your experience with building a house without a concrete topper. It's arguably easier, isn't it. Then add back the "hassle" of the panel install over the subfloor, which isn't usually your hassle if the heating sub does it.

Hassles of the pour include, but are not limited to, extra sill plates, sleeper strips for either hardwood or carpet tack strips, leveling, damming stairwells, plugging every possible hole in the subfloor so concrete or gyp doesn't leak down, moisture mitigation during the cure, job site down time during the cure, floor covering extra charges and material waste (hardwood guys HAVE to span at least to the sleepers, limiting them on how they deal with slightly warped wood strips that need more nailing to straighten them and hold them in place). Didn't mention subfloor sealing because not everyone does it, but many do, adding yet another dimension to both the hassle and the cost/ft2.

When the trades all pack up and go home, the owner is left with either a time-lag slab that usually requires them to "leave the d**n thermostat alone!" or a highly responsive floor system that can modulate heat delivery in real-time, allowing them to fiddle with the T-stat as much as they want. As a homeowner, I'm miffed when I pay several thousand dollars for something that I am no longer master of.

For me, high mass is like having a car with manual transmission and only one gear - 4th. And only one brake, the emergency brake. It would take a long time to get up to highway speed, but once there, no problem. Stopping would still be possible, but would also take longer and require a little more finesse and effort.

Well, it appears that I have fully uncloaked my anti-mass bias, haven't I? From a performance standpoint, and from a construction process standpoint, I still have a hard time understanding why someone would opt for a concrete pour unless, as you mentioned, they really LIKE having stained concrete as a finished floor, or are building slab-on-grade.

Radiant floors in concrete have been around a long time, and likely will be around a while longer, but it will still be a puzzle to me when cost-similar methods are available that reduce job-site hassle and give the owners more control over their comfort environment, floor covering choices, and a better heating performance.

Sorry for such a long post. Hope this helps.

We're actually doing a 1/4" overlay with a polymerized product. This lets you do smaller areas at a time. If my attachment comes through it is a sample from one of my suppliers. I love the look and not having to worry about the normal problems of hardwoods over hydronics. Having said that I'm sure that some would prefer the real wood. Did some work on one of the local reserves many years ago and on of the Elders gave me some good advice. The conversation was going on about why can't we all be the same and like the same things. He said to me "Young man (and I was once) Young man he said I am very happy that we are all different. If everybody wanted the same thing, they would all want my Wife!"

Barry - fences tend to have pointy objects;-) For my place 3800 sq. ft. of over joist space, I figure it would have cost me close to $4.00 extra to go WB route. With my spans the extra weight of concrete increased the cost of the joist system less than .20/sq.ft. There is the extra cost for the sill plate but it is actually a bonus when we do custom homes. We lay down the extra plate including around stairwells and than let the customer view the floor layout for their approval. No wall changes latter! Also plates don't wash out like chalklines. Carpet tack is installed with PL400 and there are many different ways of installing hardwood but yes if you go the sleeper route is is a hassle. Also increases noise and echo. I simply will not do natural strip wood over radiant due to the problems it creates in our climate. Engineered products either float or glue down. There is no hassle with concrete (or gyp) pour if you are use to doing it but you do have to allow some time for drydown (cure) Just seem to me to be less hassle than dealing with exposed grooves open to weather and trades. One of the big reasons we switched to osb from plywood was the delam factor and now you would have water penetrating right to the core not just the surface. A proper designed slab floor with in slab sensors will very seldom over heat. If it did you could still ventilate with your fresh air system. Barry - you are probably not as familiar with high mass in cold climates as I am and I am not anywhere near as knowledgeable about the WF products that you are so I'm sure the is benefits to both that would apply in different areas of the country. I just think the price is to high. Bob

strip wood over radiant should work fine if you are controlling humidity at all and install at a good moisture content. are you seeing other problems?

Pointy stuff and sometimes splinters!

Your point regarding the hassles of exposure to weather, construction, and other trades is well-taken. That's actually one of the concerns I've heard over the years from other GCs.

You are also correct about the mitigation that can be employed to reduce the tendencies of slabs to over-shoot.

I really like the added benefit of laying the sill plate down before walls in getting customer sign-off before framing them. Great idea!

As for the hardwood-over-radiant issue, you may want to check out http://www.launstein.com/, a hardwood flooring company that is very knowledgeable about radiant and hardwood. They've tested nearly every type of radiant with most of their hardwood offerings and have openly shared their findings. There is LOTS of technical information available now that should provide some better information about how hardwood and radiant can work real well together. The fears and problems of the past CAN be reduced, if not eliminated entirely. Hint: It's more about humidity control and evenness of heat than it is about radiant floors in general.

Again, about the cost - we'll need to go offline for that.

B

Rob and Barry - if you look at Launstein's results both their sample at 30% humidity show issues after just 120 days. Here in Alberta it is difficult to maintain much over 30% most winters and over 30 @ minus 20 has condensate forming on windows. While this is an issue for any type of heating system it seems to be worse for radiant. I suspect it is because the heat is applied from the bottom and the top is being most affected by humidity change. The strips of hardwood swell and shrink the most on the top surface forcing the strips apart and than gapping open. It is not so much about the level of humidity as it is about the change in humidity. If you can keep wood at a constant humidity it doesn't matter wither it is 30 or 90, the woods dimensions stay the same but as soon as you introduce change in levels, the woods dimensions change. So when we have 30% during the winter and then the home goes up to 40 or 60 for any reason, the wood swells. When the % goes down again, the joins open and expose more raw wood making the next cycle even worse. This is one reason prefinished including edges fair better that natural wood site finished. Using engineered products with backer helps to stabilize the hardwood but more importantly all the joints are finished so each can give a little and you don't notice the flaws.
Just my thoughts and feelings on hardwood. Some of the professional installers here might see it differently.
Bob

30% is the bottom end of the range of acceptability in residential construction. if it were me, I'd add humidification to the house and use better windows, regardless of flooring choice. maybe upgrade the HRV to an ERV with preheat to help retain the humidity as well.

It depends on the wood, the water temperature and the humidity. Weather windows sweat or not has more to do with the quality of the window and the installer. My new windows will suffer 40% humidity at -20F and the old ones 1978 start frosting at 5F.

My brothers 100 year old, 4-square, with 5" plank flooring is still perfect after 20 years of 180F water on/off system and no humidity control. Engineered would is more stable, generally thinner and can be operated at lower temperatures.

I agree that 30% is low, but with the condensate on windows in conventional home most people don't go much higher or rather are hesitant to add humidity. Badger's number appear very close to my observations. Last night was minus 22 C and in house rh was 39. My windows (triple glazed, low e argon filled) were just starting to show a bit of condensate in the corners.

Badger - was your brother's hardwood over radiant?

Yes. Staple-up under southern yellow pine in western Wisconsin. I am not recommending it understand, I just don't think that all the concern is always warrantied. As is suggested here, humidity is the thing with all wood. Careful system design including outdoor reset is a must.

I agree that "the concern is not always warrantied" You need to assess all the variables and design around them. I'm not a high stress guy so I avoid thinks that cause me stress in the past. 3/4" hardwood over heat causes me stress ;-) Outdoor reset properly set up will reduce the spiking in heat and reduce stress in both me and the wood. (and in my opinion one of the big savings of energy in today's systems) Two thing. The yellow pine is a soft wood with much more give than oak etc. due to the oils in the wood and it is often laid up a full inch and one half thick. Two- 3/4" hardwood tends to have the nails protruding through the subfloor making staple up a pain. I guess this is one place where the warm board would really shine. The installer doesn't have much excuse for hitting a line when he can see them.

Yes. One of my early staple-up systems, direct contact no mixing perfect performance. I don't do this anymore but it makes me think the problems with wood floors and radiant systems are often exaggerated. Much has to do with the design load and operating or design temperature of a sub-floor system. If you have to cook the floor to satisfy the thermostat, you need more insulation or a second stage to take the load off while in outdoor design conditions, something I did in my own home in fact. My floors, maple, oak and pine were all unaffected by radiant floors though 100 years cured.

As Badger noted earlier, it is humidity that is the main culprit. Not the actual humidity level, but the CHANGE in humidity. It has a MUCH more dramatic effect on the dimensional change in the wood than a change in temperature.

Here is an equilibrium moisture content calculator that will give a clear understanding of the more powerful impact of humidity change on wood dimensions.

http://www.csgnetwork.com/emctablecalc.html

Play with this a bit by radically changing either the temp variable or the humidity variable to see what effect it has on the EMC of wood.

There is a direct relationship between the PERCENT CHANGE in humidity and the PERCENT CHANGE in EMC and the PERCENT CHANGE in dimension across the grain of wood.

That relationship is different for each species of wood, but the relationship is still direct. Softwoods have a more dramatic dimensional change per %change of EMC than hardwoods.

Another excellent resource comes from the USDA: http://www.fpl.fs.fed.us/documnts/fplrn/fplrn268.pdf, which gives the resulting EMC of dead wood left to the ambient RH of a geographical area. I haven't read the whole thing yet, but I'll be looking for the % change in humidity from one season to another. Wide swings would prompt me to artificially control the indoor humidity levels to insure proper health, not just dimensional stability of the wood products in my home.

It is also widely accepted that forced-air furnaces have a more dramatic effect on indoor humidity levels than radiant floors. My f/a furnace drops my humidity levels down to the high 20's quite often, and next pile of disposable cash goes to a humidity control system. I live in Oregon, where the RH outdoors stays high enough to grow mold and moss on nearly any flat surface that is left to its own, so we know that it is the furnace, not the environment outdoors, that is causing the wide RH indoors.

I said all that to say this: Concerns about dimensional stability of wood floors should be aimed more at controlling indoor humidity levels and less on the floors as a source of heat. Keep the surface temps below 85 degrees, use dimensionally stable species, make sure the heat spreads as evenly as possible, and your hardwoods will fare no worse with radiant floors than with any other source of heat.