I am building a new home and want to include radiant hydronic heating for the main floor (basement underneath) and the master bath (garage underneath). I’ve done some research and found a company called Warmboard that provides a 1 1/8″ plywood subfloor of tongue & grooved 4×8 sheets that have a pattern of channels in the surface for the tubing. There is aluminum stamped onto the surface that the tubes rest on.
Has anyone used this product or anything similar? How would you compare it to staple up techniques? I considered a mud floor, but it’s more costly. (I think.)
Replies
If you do a search for "Warmboard" and limit it to just the Energy folder, you'll get 81 past references to it. Have yourself a little bedtime reading and then let us all know what questions remain.
I would rate it as far better than staple up and quite a bit better than a pour.
>quite a bit better than a pour
Why?
Faster response time. More responsive. More even heat distribution. Lighter weight on your structure. I think I am missing a couple of reasons.
Please note I speak only of light-weight pours over wood floors. Not a slab.
>Please note I speak only of light-weight pours over wood floors. Not a slab.
Ahhhhh. OK. Thanks for the qualification. No argument then.
Thermally, I think Warmboard an excellent product. Very good heat distribution due to the laminated layer of Al.
Better thermal performance than a staple-up, but at $4.50-$5.00 a sq ft vs $0.75 a foot for 3/4" CDX T&G ply, much more expensive up front than staple-up. I'd use the same insulation under Warmboard that I'd use under a staple-up.
I was told that Warmboard is now reaching "critical mass" (their term) in production, meaning they're getting to a new efficiency point in the cost vs production curve. Translated, that means the price they charge for their product should be coming down.
I don't recommend lightweight slabs for myriad reasons.
If you really want radiant heat then go with a thin slab or a lightweight pour like Gypcrete. What you want is "Heat mass" A board floor will heat up faster but will not retain heat. The heat will dissipate quickly and take much more energy to keep warm. A heat mass will truly radiate heat especially if you don't insulate it over with wood flooring or carpet. Tile or slate adds to the mass and will thus make the floor more efficiant. Warm boards try to mitagate the loss by using a foil reflector but without mass it is just "make believe radiant". If you are building a new home then you can use appropriate joisting to carry the extra weight. Warm board is more a retrofit solution for remodlers.
Since no one else has picked up on it, I'll jump in. I have a gypcrete floor (and two full slabs) and am not particularly fond of the gyp. The only thing I really like about it is that it's a good sound barrier.
There are high-mass solutions and lo-mass solutions and those in the middle. For the main living areas, I'm fond of the the high-mass, i.e., thick slabs. For our bedroom level, I would have preferred the low-mass, such as Warmboard, because of its responsiveness. I don't consider it to be "make believe radiant". The medium-mass of gypcrete has too little mass to hold the heat for long, but too much mass to just heat at bedtime, for example. A more responsive system would have been preferable in those rooms that we only use at limited times of the day, and Warmboard would have fit that bill.
Cloud,
We are planning to do gypcrete for our main living area. We have been living in our basement for 6 months with radiant heat in the slab. We set the thermostat in October and haven't changed it since. Seems to be fine and comfortable. Wouldn't gypcrete be the same?
Having said that, I do think the bedroom is a tricky area. I had our plumber stub a gas line to our master bedroom for a future gas fireplace or gas stove. I figure that will be the fine tuning. Keep the radiant heat low and if I want some heat in the morning, reach over, grab the remote for the gas fireplace/stove and heat it up.
Also, forgive my ignorance, but do domes have thermal mass to them? If so, how do you think that affects the system?
First, I want to be clear that I'm not speaking in terms of right v wrong. Each approach offers advantages that suit one situation better than another.
Partially because of the thermal mass of the dome, I'm used to a setup where the system is off for long periods of time and yet the floor is still warm. I like that. That doesn't happen with the gyp floor. When the heat is off, maybe 6 hours later I can't feel any heat in the floor. With my slab, it'd be two days. Of course, the lead time for warming the floor would be comparable (and that's what makes it akward in my bedrooms that I'd like to be "on" for rather short periods each day). If you have a system designed so that it's always on, such as your living room, then it shouldn't make much difference--warm floors will feel warm and as long as there's no striping (warm-cool-warm-cool as you move across the floor), it's all good. So then you look at the floor as a substrate and its cost. I personally don't like gyp as a substrate, either for tile or for the bamboo I installed. I didn't like working on it. And it is expensive. I far prefer concrete. Lightweight concrete would be a better substrate in my book than gyp. But there are reasons for gyp, and I want to avoid any semblence of a religious war over that.
Thanks for the clarification. I'm just trying to gather up information. Our main floor radiant heat has not been done and I don't think staple up is an option. Warmboard is too expensive so that left gypcrete. I want to go into this completely informed. Maybe there is some other option that we haven't considered. I don't know. I like to hear about the experience of others, so I thank you!
There are a few drawbacks to gypcrete . It shrinks and cracks and to lay tile or wood over it you may have to apply some self leveling cement. That adds a little expense to the project. It is still far better than warmboard for heat mass. It is almost as good as concrete. Warmboard has negligable mass. If you are concerned about bedrooms and lag time to heat then there are always programmable thermostats that you can compensate for the time lag. You can separate the zones so that each has it's own thermostat. I am cheap when it comes to my energy bill and the most efficiant systems have the most mass.We may be slow, But we're expensive.
Certainly don't want to draw this out, but some of what you say doesn't quite mesh with the 1 1/2" of gypcrete that's on the floor above me right now. For example, tile and wood coverings don't necessarily require self-leveling cement. For tile, for example, the gyp installers I know are recommending the use of an anti-fracture membrane because as the gyp cracks, it will otherwise cause the tile to crack. As with the SLC you mention, it's an added cost that affects the economics of the system.
And I'd challenge that hi-mass systems are inherently and always better than lo-mass systems and that gyp is almost as good as concrete. So what that Warmboard is lo-mass? If it provides the btu's I want when and where I want them, then it's an effective system. My position is that it depends on the purpose of the installation. For rooms that have minimal use, a lo-mass system will be more economical than a hi-mass system. I love my 8" slab and the way it heats, but other ways can be more effective (i.e. cost less) in other situations.
Cloud, you are the best informed and the most accurate poster on this thread. I applaud you!
To the rest... CH is right on. Just because someone tries to sound like an expert doesn't make his or her advice any good. Cloud's knowledge on this subject would put many "pros" to shame. So when he peaks, listen up.
So you imply that my advice isn't worth a s---. I hate those suck up posts. They are waste of time to read. You are about to make my ignore list. Here at Lake Tahoe we only average a mere 25 feet of snow a year. It is snowing heavy right now. I am a General Contractor and have been building here for the last 15 years. I have been at it for over 30 years now. I have never seen anything except Gypcrete for in floor heating in living spaces. A garage is about the only place you ever see a concrete slab with hydronic heat. I have worked in dozens of multimillion dollar homes and almost every one has gypcrete. I have never seen warmboard or any other system used for in floor heating. I know it is available but the conventional wisdom goes with the tried and true. I guess you imply that all the plumbers around here are ignorant too. I will have gypcrete in my own home. I am building it now. We may be slow, But we're expensive.
Myci, please understand that I'm not intending to deny your experiences. Different places, different methods. We live, we read, we learn. Most of what I do is single level and so the rfh is in a structural slab. Vast majority of what I see. Mostly gyp is used around here for flooring in multi-story apartment buildings (without rfh) be/c it satisfies the code for fire resistance. But for multi-story residence, I wouldn't be inclined to use gyp unless the builder and/or client requested it. If I wanted mass, I'd look first to a structural elevated slab, second to lightweight concrete. Or I'd see if a lo-mass system would work. With gyp here at $3/sf + $350 a roll for AFM (can't remember the coverage) + subfloor, it's pricey enough for me to consider alternatives.
Can you tell me more about how you use it? Sleepers? How do you install wood floors over it? Any problems with tiles cracking over the SLC over the gyp? Ever use the membrane instead of the SLC? What do you budget for it?
I was reacting to wethead and his dubious drivel not you. I am usually a subcontractor doing woodworking and carpentry mostly. The observations I make are just observations of other trades doing their work. For wood floors I have seen sleepers installed before the gyp pour at about 8" centers. That is probably the better way. I have also seen wood over gyp that was over two layers of 1/2" plywood over SLC and adhesive. The SLC was so the plywood would adhere without using fasteners. The gypcrete tends to dry a little concave over large areas. The SLC fills and flattens the concavity. Most tile, slate,quartzite or other stone was installed directly over the gyp with thinset or a thin mud bed. I am not the flooring contractor so I can't tell you if there were callbacks. My gypcrete contractor tells me it is OK absolutely to install tile directly over the gypcrete. I asked him being concerned by things I read at this forum. We may be slow, But we're expensive.
Paula,
one of the advantages of having a high mass system, is that if (when) the power goes out on a cold day you'll have a longer lag time before your house cools down. That being said, have you looked at having an engineer design a nice elevated structural slab for the first floor? It might not be any more expensive than Warmboard, extruded aluminum plates or a beefed up wood floor with gypcrete or lightweight concrete on top. I've got structural concrete floors for both the first and second floor of our home and radient floor heat - our home's temperature doesn't vary by more than 2 degree's from what the thermistat is set at (usually 72F).
>My gypcrete contractor tells me it is OK absolutely to install tile directly over the gypcrete.
fwiw, my gyp contractor gets apoplectic over that. Says it's a sure way to crack a tile. The thinset will adhere the tile to the gyp stronger than the tile itself is. Then when the gyp cracks, something has to give, and it's the tile rather than the thinset bond. Different regions, different experiences. Maybe my guy just wanted to sell me 375 worth of AFM! <G> But, no cracked tiles!
I am not sure why you are so upset at me. You have had no experience with anything except gyp-crete type products and yet you want to come off as an expert. Whatever you wish sir.
I will state my case.
I am a highly trained, highly experienced plumbing and heating contractor with a reputation for my depth of knowledge and skills with hydronic heating. I specialize in RFH. I associate with the best of the best in the industry and learn from them constantly.
Now, put that resume up against a GC who has had extremely limited (by his own admission) experience with RFH. He has never used or studied any type of RFH except light weight concrete pours.
Now, who do you think would be the most qualified to give advice on Warmboard type products?
All I did was point out who was giving accurate advice in this thread. Sorry it wasn't you. I wasn't so much trying to stroke Cloud's ego, as I was pointing out the faulty premise upon which some other posters' advice was based.
And YOU are about ready to put ME on ignore for that?
Sir, based on your post to me, I would appreciate that. I have nothing to hide here. There is no reason we can't just all get along and have a good time here. But when I see posts that are documentable as BS I will speak up.
I won't even go into all the errors in your post. To tear you down was never my intention. I was trying to be diplomatic in how I pointed out the BS on this thread. I tried to do it in a positive manner.
So the ball is in your court. I have been here a long time. I have the credentials to back up my posts on plumbing and heating. I am not going away, nor will I cower in fear of anyone here. I welcome intelligent debate and challenges anytime. I wish more pros in my field would post here.
So... what do you say we just leave it at that? Life is too short to get into a pissing match on this forum.
PS. Don't take my earlier posts so personal. It's just business to me. It should be to you too.
I was only disagreeing with your opinion of warmboard being "quite a bit better than a pour". I guess you don't live in an area where the power goes out during storms. Warmboard would be instant off in the case of a power outage. A system with mass might carry through a shorter outage of a half a day or so depending on the mass. Instant on is not as much a concern to me as the risk of instant off. I don't have to be a wonderful plumber to understand elementary physics.We may be slow, But we're expensive.
Cloud Hidden, are you in Alaska??, I always enjoy reading/learning, now if I could just remember. Any who, I'am curious as to how many zones/pumps that you have in your home. Do you have any foam under your slab, I'am guessing that you do. As Myci, mentioned, an individual could break up their home into separate zones, depending on their individual needs. My only experience,with this in-floor heat is, one project- new cons. Main floor, 2"foam, VB, 2" sand , 4" concrete, 2nd floor 3/4" ply, 1 1/2" gypcrete , carpet. basically, owner lives 1 st. fl. only, home has 6 zones, she loves her heating system, 2200 sq ft livable, seemed a little expensive when I paid the HVAC, but hey, the owner is Happy, utility bill is less then her old home 1800 sg ft forced air system, Be safe out there Jim J
Western North Carolina, nestled comfortably into the Southern Appalachians--the oldest mountain chain in the US. I have a bunch of zones and a programmable logic controller for them. The walk-in basement is a 4" slab. We've insulated about 3' within the perimiter. Because of a lot of things, but mostly the type of construction, we have never even run the heat there and it stays above 65 year round. 8" main floor slab, and bedroom level with 3/4 sub and 1 1/2 gyp. As mentioned, likely woulda redone top floor as a more responsive lo-mass floor. We're only there to sleep really, and the mass in the rest of the house--'bout 1.25 million lbs of concrete--is enough to keep it temperate all day long. I'd like to just heat up the floors from say 8 to 11 pm and 6 to 8 am and leave it at that. Tough to do with the system that's there. And it's not that any one of these systems is wrong--they all have a place. Just fit the tool to the job.
I have staple-up in my house, and I am comfy. The house is a copy of the Sarah Susanka "Not So Big House," and is a three-layer cake with about a 900 sf footprint. Bottom walkout level is hydronic in concrete slab, framed floors above have the staple-up. Floor framing is I-joists, and we tacked 15-1/2" rips of 1" foil-faced rigid foamboard to the bottom surfaces of the top flanges, creating an insulated cavity 1-1/2" deep for the hydronic tubing to reside in.
The past winter had a number of nights at 25 below or deeper, and quite a few cloudy days when the daytime temps barely broke zero. We were comfy the whole time.
The entire house is insulated with sprayed in place polyurethane foam, and we took the time to seal every possible air leak spot.
Oh , so much info, so few brain cells, anywho Cloud Hidden, thanks for the answers. I'am guessing that you have,, well do tell, 4" slab in basement, 8" slab on first floor, what have you got, Cloud Hidden, a structural, pretensioned slab on your first fl?? For yesterday, I was wondering type wall construction that would compliment an 8" slab. Anyway Cloud Hidden, sounds as if your hvac system is working is so well. Be safe out there Jim J
Not pre- or post-tensioned. Just a slab. As for the support system...whole other story not related to this thread. Let's just leave it as elevated slabs are in the mix as a flooring system along with all the others. People have to evaluate costs, materials, methods and see which works best for their combo of heating needs, structure, contractor, budget.
Paula,
Another option that has not been discussed is the Stadler panels that are like the Warmboard, but are attached to your subfloor. I have no experience with them but maybe someone else here could pipe in and add their experience.
JasonIf it wasn't for bad luck I wouldn't have Any!
100% A-OKAY
To fill out your research...
http://www.radiantpanelassociation.org/i4a/pages/index.cfm?pageid=1
I have been doing a bunch of research on the same thing and found many other comparable products. Prices are in canadian so multiply by 1.4 for US funds.
Warm board is a 4x 8 sheet at $222 per sheet or $6.94/sq ft (price quoted from supplier)
Thermalboard (similar product but applied over subfloor) sheet=16"X48" @ $26 per sheet = 4.88/ sq ft plus $0.56/ sq ft for sub floor= 5.44/sq ft
looking at "climatepanel" as well which is simillar to thermalboard but do not have a quote back yet. They want my floor plan for an all together bid. Overall the warmboard is expensive and I can't see the benifits over the other two systems. The warmboard is installed right away and then you have to protect it during construction. Also you pay the big bucks fo unnecessary areas like closets and other non heat required areas. Above prices are for materials, installation extra. Gets really expensive after you add 15% for taxes etc.
Cheers,
Brent
Thanks for mentioning those other two options. Sounds like you are a homeowner like me. Our builder mentioned that he would charge more labor to install warmboard since they weigh around 100# per panel. I don't know if this is typical or not, but it seems fair since it would require more labor to install.
Homeowner and building a custom home myself. I'm looking into the benifits vs cost and comfort etc. As all installation will be done by me and crew labour is not as critical I'm looking at getting the most out of the system possible at a fair price. Right now if I was to do our entire place in the "Warmboard" materials alone (just the board) would be around $16000 then add in the cost of tubing, fittings etc and without any outside labour I'm looking at about 30K. This is where the retarded part comes into play because you can purchase a complete forced air system with a/c installed about 4 to five times for just the material money. How would you ever in the lifetime of the house x 2 recover that investment? the comfort level may be higher in some instances but is it worth it in the end? When I wrote warmboard I figured thier subfoor would be 2 to three times the cost of regular subfloor 54 to 80 bucks a sheet- it maps out at almost 10 to 12 times the cost. Seems to be way out of my league.Cheers,
Brent