Gypcrete, Warmboard, Quik Trak... Which should I choose

pk pgh

I am building a new home in western pennsylvania. I have decided to go with radiant heat for the entire house. However, I am having trouble deciding on which system to implement. I have heard good and bad things for gypcrete, Warmboard, and Quik Trak. Any comments, suggestions, or experiences would be greatly welcomed including any that would suggest another product or even change my mind to a cheaper forced air system! Also, as I am the g.c. for the project, any recommendations on heating contractors in the Pittsburgh, PA area would be welcome. The house is over 10000 sq feet

Gordy

Not a sales person

 So no monetary interest. Warm board will give you the lowest water temps which equals less energy. And as far as material costs remember you are taking care of the sub floor, and radiant minus tubing in one shot. So when comparing costs you need to deduct your sub floor material out of your building costs. Labor will be a little more than a standard sub floor install. There is some thought, and planning that goes into the warm board install.



With gypcrete floors have to be modified to handle the extra PSF. Plates need to be built up to allow for the extra depth of the gypcrete.



Forced air don't look for me to talk you into it. I have had it, and once you go radiant when properly done you will never go back.. The only draw back is cooling so you still need air handler, condenser, and duct work for that.



Gordy 







Gordy

Simply Rad

Options

 If cost is the deciding factor, then forced air wins without any doubt.  If you are looking for comfort and efficiency then radiant is your choice. I have completed many radiant floor projects, from basic to 18,000 ft2 homes, from staple up plates, gyp, concrete, quick track and Warmboard.  My personal opinion( which includes feedback from 40 customers) is that Warmboard (WB) provides the most comfort and efficiency.  For me the radiant floor heating installer ,I find it easy to install, the system is document from the plans WB provides and the nothing compares to the system performances,  I have homes with both WB and concrete slabs and the customer feedback has tremendously favored WB. 

Now for the GC's(general contractors).  I have had a lot of negative feedback from GC's that have not used the product.  I am not sure how they can possibly have an opinion with out using it but they do.  Reality is WB is heavy( 4'X8' of 1 1/8" sheeting), its a custom layout and  you need to take your time and follow the plans that WB provides and it can be slippery when icy or wet. 



I find those cons to be negligible to the benefits that WB provides.  Lots of contractors preach the concept of "thermal mass".  Well That is what the home is, its full of great places to store radiant energy, drywall, wood, beams, insulation, they all hold the heat.  My personal opinion is that you want your radiant system to transfer the energy and not store it in a concrete floor.  The house will hold the heat, allow the floors to transfer it.  I find that WB works best with condensing or high efficiency heat sources that use outdoor temperature feedback(OTS-outdoor temperature sensor).  The weather is always changing so why should your floor temperature to provide you a very consistent environment?  Concrete is lazy and does not want to change, and it takes hrs to change,  Not with WB changes can begin happening in 15mins. 



The idea is to provide you with a constant environment, and not only is WB comfortable but extremely efficient.  On average I supply the floors with 90F fluid... and that is the sweat spot for condensing boilers, solar or ground source heat pumps.  What that means it less energy and money to provide you with the ultimate in comfort. 



Just my 2cents and maybe alittle more

Gordy

2 cents plus some.

   That was beautiful. Response time is everything.



Gordy

Gordan

In that vein...

Let's not forget radiant ceilings. Low mass (fast response), inexpensive to put up, not sensitive to floor coverings or furniture placement, and shouldn't require much warmer temps - if at all - than Warmboard, with similar tube spacing.

Sal Santamaura

Or get Warmboard's benefits...

...by using Warmboard R on the ceiling, then drywalling over it. 



http://www.warmboard.com/radiant-heat/warmboard-r/

Gordy

Radiant ceilings

Have them through out, and love them for all the reasons Gordan says. Save the radiant floors for basements baths, and tiled kitchens.



Gordy

MikeG

Drywall thickness

Has anyone used Warmboard R in a ceiling application with less than 1/2" drywall.  Looking at the weight issue in an older house or retrofit application.  Since the ceiling is totally backed up with the warmboard would 1/4" or 3/8" drywall work?  Structurally it would work but is there any issue with the thermal part of thinner drywall.  I've done remodel work plastering and drywalling using 1/4" over existing surfaces with no issue.  Not real fun hanging 1/4" on a ceiling.   I've stripped out ceilings with 3/4" furring strips or plywodd then 1/2", but in that case needed the backer support.  Thereare some light weight drywall boards out there.  Just seeing what others thought.  I may try it in my own house.  Thanks  Mike

Gordan

Warmboard R is OSB...

It would have to be heavier than furring strips. As far as thermal performance, it could only help... less R value on top (eh, bottom) of the conductive layer. Heck, if performance were the only concern, spraying some ceiling paint on the Warmboard and leaving it exposed would do even better! The paint would be to increase the emissivity (which is low for bare shiny aluminum.)



But how would you stop 1/4" from sagging on a ceiling application?

MikeG

Total weight

Gordan,

What I was looking at was total weight of the system.  The warmboard R which is OSB, on the whole ceiling, plus say 1/2" drywall, vs using thinner drywall.  Maybe not that much difference in the big picture.  The extra weight may be an issue in an older house.  In going the furring strip route, ther are only 3/4" strips, with thin plates and then 1/2" drywall.  Proper insulation above would be installed in either method.  We used to do the 1/4", sometimes 3/8" drywall over existing wall or ceiling surfaces to get a more uniform surface.  The surfaces had to be reasonably sound, but maybe hairline cracks or old wood lath and plaster.  Construction adhesive or a drywall mastic and screws made a good install.  In this case since the warmboard is all OSB, a closer fastening pattern is needed.  Don't know what that would be, 6"x6", 8"x8".  Mabe some adhesive.  Maybe it's all more hassel than the benefits.   Mike

STEVEusaPA

you could use either....

After you installed the warmboard, like you said, you would have full backing.  Just glue and screw, and screw.....  Although you probably already know, unless you're skim coating the whole ceiling, I think it's pretty hard to tape/spackle 1/4 inch drywall and have a nice finish.  The screws dont dimple like they do with 3/8 or 1/2, and even the factory edges aren't that great.  Plus 1/4 inch, over head, you break a few hanging them.

Jean-David Beyer

spraying some ceiling paint on the Warmboard

I hope I never need to install a radiant ceiling (i.e., have a professional install one), but my main heating zone is copper tubing in a concrete slab; slab and tubing are a little over 60 years old so they may have used a beneficial mix for the concrete. Since the pressure does not go down when I turn off the makup water for over a month, I assume it is not leaking yet. But I think of what I must do if it happens. And a radiant ceiling makes the most sense. I figure if the floor leaked, there would be no point in getting an IR camera and the jackhammer team to fix it because, like bedbugs, if there is one leak, there are more leaks to come.



If I have Warmboard-R put up on my existing ceilings (painted real plaster), I wonder how heavy it is (with the tubing and the water in the tubing). Would it be practical to glue the Warmbard to the existing ceiling with industrial strength contact cement or something? Or would the weight just tear the paint from the plaster? I wonder if the joists are easily found to nail the warmboard up there, or whether the plaster will have to be ripped out? If the latter, I could stuff the area with fiberglass insulation.



But once that is all solved and the warmboard is installed, with the tubing (Pex-Al-Pex, I assume), I do not think I could stand just painting it. But maybe contact cementing something very thin and painting that would do. I doubt anyone could do a good job with aluminum foil, but maybe 0.040 or 0.032 inch aluminum sheet would work. It would be low-R for sure. I wonder about the joints, though. Tape and heavy paint? Has anyone tried something like this (and is willing to admit it)?

Gordan

I was joking...

...to make a point. :-) I don't think there are too many who could stand to have their "business" in everyone's face like that. 1/2" drywall is R .45. It will work more than fine; there's no reason to resort to desperate measures! Especially since, as I recall, you're already running higher temperatures for your baseboard upstairs. (In fact, one issue with using drywall is that the manufacturers recommend not exceeding 120 F water temperature, lest the gypsum core get damaged, so you'd want some way to limit this.)



In your case, all things considered, warmboard on the ceiling may be overkill - unless the extra materials cost is offset by lower installation cost.

Jean-David Beyer

joking... ...to make a point.

I know your point. It just might work in a den or something like that. Paint the ceiling white, but cover the tubing with a sharply contrasting bright color, such as red or blue. In other words, since you cannot hide it, flaunt it. Trouble is, I have no den. I might try it in my computer room, but not my kitchen, living room, bathroom, or bedroom.



As far as warmboard being overkill, I have not priced it. But trying to consider the alternatives, what would I do? Rip out the ceiling (I might have to do that anyway) install lots of insulation, hang the tubing down and hope it contacts the drywall I would put up? Sounds lousy to me. I worry about getting a good enough contractor to do the job at all. It seems to me that Warmboard R or something like that would make it harder for the contractor to screw it up. Installing the radiant in the ceiling is going to be trouble because the joists run at right angles to the desired direction of the tubing. I cannot have all the floors upstairs ripped out to work from above, and working on ladders sticking up tubing in the ceiling looks too difficult to do a good job of.



It seems to me a contractor could get the old plaster ceilings out of there, put in the paper-backed fiberglass insulation in there, and then fasten the Warmboard to the joists. He would not enjoy putting the tubing into the warmboard, but surely that would be better than just pushing it up there under the insulation and hiding it with drywall.



I wonder if thin drywall glued on top of (actually beneath) the warmboard would work out. I would just as soon use the thinnest drywall possible, consistent with it being strong enough to support itself. But a suitable contact cement should do that, I hope. Seems like a bunch of contractors; One to put up Warmboard, one to do the hydronics, one to deal with the drywall on the ceiling. One to paint it.



I hope my existing copper tubing lasts longer than I do.

Gordan

It ain't all that complex...

Punch some holes in existing plaster in order to blow in some cellulose on top, furring strips attached to the ceiling (screws through into the joists, construction adhesive to the plaster) and then staple transfer plates to the furring strips (on one side), snap in the tubing, drywall over. You lose 1 1/4" of ceiling height, big deal.

Jean-David Beyer

You lose 1 1/4" of ceiling height, big deal.

Since my ceiling height is just under 8 feet, and I have track lights on the ceiling, and carpet on some floor, losing 1 1/4" is a big deal. Looks as though the plaster will have to go. I would prefer to glue one half of each transfer plate to the drywall, but that does not seem to be a practical proposition.



I just hope my copper tubing lasts another 25 years, because I probably will not. I am 73 now.

Gordan

Think of it this way...

In your old age, you might well lose 1 1/4" of height yourself. :-) Plus, you're not as likely to practice your golf swing indoors.



My ceilings were just under 8', as well, and I have track lighting, and losing those 1 1/4" wasn't a big deal for me. But I don't have any friends who are NBA superstars.

Jean-David Beyer

In your old age, you might well lose 1 1/4" of height yourself.

I already did. It is not me I am worried about: I have a friend well over 6 feet who bumps into lights already. But I could keep a coffee table under the lights and subtly guide him away from them. and he would not be going into the other rooms. I hope the drywall in my undersized, unventilated bathroom will not suffer from the water vapor and condensation. As it is, I cannot keep the paint from peeling off from the ceiling. Maybe with heat up there, it will reduce the condensation.



I guess I will wait and see and pray that they put a mix of concrete in the slab that does not eat copper tubing.

MikeG

Any other products

Is there a product that combines the furring strip concept and thin AL plate, like warmboard R in just long strips for 1/2" tubing?  I entertained the idea Warmboard R in my 12x14 utility room ceiling.  Currently it is open ceiling/floor joists.  Insulating not a problem.  With the can lights to work around I thought there might be too much waste to work the grooves where I wanted them.  I'll go back to my original plan of furring strips, thin plates and 1/2" drywall.  Is there any issue of just leaving the end loops free of any support for movement.  They'll just lay on the top of the drywall.  Part of the area above the utility room is a bathroom, 7'x8'.  If I didn't put insulation above the ceiling in this area, is there a way to figure out how much heat will go up?  I can always use a little more heat in the bathroom.  The floor is 3/4" plywood, 1/4" underlament and then linoluem.  I already entertained the idea of plates under the floor, but nails on 6"x6" and did'nt feel like doing the grinder thing since I'll have the ceiling radient.  I shouldn't have any issue getting enough heat in the rest of the ceiling for the utility room, but I have to relook my heat loss calcs.  Currently the wals and unheated above area is insulated but  unfinished.  There is 60' of soft copper in the gravel fill under the 4" concete slab.  2" extruded foam under and around perimeter.  I run 112-115 degee water through it now, and it works pretty well.  It has it's own pump but it is wired in with another small copper BB zone so I can reduce short cycling.  I'm getting closer to finishing this room so I'm just looking at ideas.  I know the copper under the floor may have a short life so all my piping is installed to bypass it if necessary.  Any ideas welcomed.    Thanks  Mike

Zman

How much passive?

I think the first question should be, how much passive do you get?High mass systems with tons of passive are a nightmare to control. They just overshoot and undershoot all day long. If you have passive go low mass.I would also recommend you keep it simple. If you do an accurate heat loss calc, then size the panels to meet the loads of each room based on the same supply temp, you can run the whole house off the boiler's built in reset curve and have a great simple system. Read "radiant precision" then only hire contractors who "get it"

NRT_Rob

for radiant ceiling

we love radiant ceiling, but for heat only applications you can crank a ceiling's output with just strapping and light plates.



when we are looking at cooling as well, we go to warmboard-R to really maximize output. or if cost effectiveness is not the biggest deal for heating as well.

Gordan

Rob, what kind of heat spread are you seeing in your installs?

Just yesterday I took some measurements with an IR gun from up close, and at 12" o.c. I'm seeing 95 F at the tube all the way to 79 F 6" from the tube. I took the measurements at half inch intervals and averaging all of them, it came out to 84.5 F. Is a sixteen degree spread more than I should be seeing?





Plotting it, it kind of looks like a peak right at the middle (no surprise), a slower drop-off for the first 2", then a faster drop-off for the next 2", then it kind of levels off (as it gets a little bit of contribution from the neighboring run.)

NRT_Rob

depends

on warmboard we see very little spread indeed.



with plates/strapping, we don't see a lot of conduction past the plates, so there is a definite drop after you leave the aluminum and the wider your spacing the more you'll see.

Sal Santamaura

Radiant ceiling cooling in the humid northeast?

Rob, how do you set up / run Warmboard R ceilings for cooling in your area?  How do you avoid condensation problems during periods of high humidity, i.e. most of the time cooling is necessary in the northeast?  :-)

NRT_Rob

several ways

dehumidification coil, ERV, tight home, condensation monitors. all necessary. but once humidity is controlled, should be all set...

Gordan

Construction detail...

This is thin "omega" plates, 4" wide, 12" o.c. backed by polyiso board, with furring strips in between.



Do you see a drop of a couple degrees even over the plates?

NRT_Rob

hmm

need to crank up our ceiling again to test.

Gordan

I'll post my numbers this evening

It'll be interesting to have something to compare to. I took measurements at half-inch increments from no more than 2" away, to avoid the "cone."

Gordan

Ok... here we go.

0": 95

.5": 93

1": 92

1.5": 90.5

2": 86.5

2.5": 83.5

3": 80.5

3.5": 80

4": 79

4.5", 5", 5.5", 6": 78.7

Greg_23

where to buy gyp crete

where can a contractor buy lightweight cement or gypcrete?