Poured slab, staple under, radiant panel ........ ?????

[Fi-Q]

Ok,

Let’s try to make this short. 3 Years ago decided to get our house build. Took a building technician for the drawing, was really disappointed, so took an Architect, was even more disappointed… So I modified & completed the drawing myself on Autocad. So the drawing were not sealed .

It was decided since a long time that I wanted in floor radiant heat, and back then decided too go with a in slab radiant heat on every floor.

I gave the foundation and the shell of the house to a contractor (basically getting it weather tight, with roofing, windows, door, Tyvex). When the house got build, I was working on the road, away from home. Then went home for a visit and found out that there was a Post, on the main floor. A post that, for me, had nothing to do there in my vision of the floorplan, in fact it was kind of destroying it. Then talking with the contractor, I found out that it was like that because of the load calculation for a poured slab on the second floor, Let say that I was not a happy camper at all, and, lets not get into details, but there was no way for me to get after the contractor for this. So it was there, a post in the middle of the living room…. And there was nothing to do about it, the way windows & door are spread around the house, putting a h or I beam was not an option….. the shell was completed, it was too late….. Then, got pretty busy, the house got over budget, ect…. Let say that for a while, the house fell way down in my priority…. So haven’t done any work on main floor / second floor since, basically finished the exterior and insulated the whole house. but haven’t touch anything else inside (Just finished a basic apartment in the basement).

So, I always wanted a poured slab for the efficiency, the low temp, ect…. But now I am starting to think getting work done inside the house. I talked to the company who design my floor joist. They say that if I am not pouring a slab on the second floor, I can get that post out with no problem.

Then starting to think that 2nd floor won’t need much heat anyway. So I think to go with staple up radiant under the second floor. Second floor have 4 bedrooms and 1 bath, want to go with hardwood floor for bedroom & ceramic tile for bath.

So I would still go with a poured slab on main & basement (Already done) and staple under for 2nd floor.

What do you guys think?

How much efficiency & comfort difference between heated slab & staple under.

Realistically, except for extra comfort in the bathroom, how much heat is really needed for a 2nd floor in a very well tight & insulated house ?

 

[711mhw]

When you say slab do you mean a conventional 4" or so concrete? If so, would your floor (without the post) support a Gypcrete type "slab"? This would/should give you close to the same performance.

 

[Fi-Q]

Was design for a light concrete slab, 1.5 in thick.

 

[711mhw]

Darn it!!

 

[jimbom]

If you have a very well insulated structure and don't install heavy carpet upstairs, you likely will be happy with staple up. Radiant floor heat is very forgiving in my experience.

 

[infinitymike]

I'm not an engineer, BUT I am a Residential Contractor for over 20 years with a degree in Architecture and close to 30 years of field experience.
(never pursued the architecture field only wanted a degree to help in my construction business)

Here on Long Island, NY, we staple under the plywood sub-floor all the time for 2nd floor as well as 1st floor.
It is rare to have a poured concrete 1st floor with a basement below. And even more rare to have a 2nd floor poured.

We do however run it through the mud of a tile floor.

On occasion we will put sleepers down on the sub-floor, run the pex through that, then cover with more plywood and the finish with the hardwood flooring.

Some manufactures make a plywood panel that has a groove routed out to except the pex.
We will install that over the plywood sub-floor and then put the hardwood right over that.

If you staple it under the floor you should install the hardwood flooring first so you don't hit the pex with a nail.
And if you put it on top you REALLY have to be careful not to hit it!!

It does work very well. IMO
and my customers opinions.


Heres a some links u might like
http://www.warmboard.com
http://www.woodfloorsonline.com/techtalk/woodwater7.html
http://www.thisoldhouse.com/toh/video/0,,20365330,00.html


Hope that helps.

 

[Fi-Q]

I will give a close look at those warm board panel. Wonder what they cost......

 

[Reggie Dunlap]

I'm a builder here in VT and we pour 1 1/2" heat slabs all the time. We size the joists according to the load, frame the floor, install 3/4" Advantec subfloor, then screw down 2x3 sleepers 16" on center. The pex goes between the sleepers and we pour lightweight concrete between the sleepers. The wood flooring then gets nailed to the sleepers. If there is tile or carpet we skip some or all of the sleepers.

We've found that this works a lot better than normal staple up radiant, as the concrete acts a thermal mass.

I've used the warm board and other similar systems in retro fit projects where we either didn't have the head room or enough structure to pour a slab. They work OK, but you can't beat a slab for nice, even heat distribution.

 

[Fi-Q]

I'm a builder here in VT and we pour 1 1/2" heat slabs all the time. We size the joists according to the load, frame the floor, install 3/4" Advantec subfloor, then screw down 2x3 sleepers 16" on center. The pex goes between the sleepers and we pour lightweight concrete between the sleepers. The wood flooring then gets nailed to the sleepers. If there is tile or carpet we skip some or all of the sleepers.

We've found that this works a lot better than normal staple up radiant, as the concrete acts a thermal mass.

I've used the warm board and other similar systems in retro fit projects where we either didn't have the head room or enough structure to pour a slab. They work OK, but you can't beat a slab for nice, even heat distribution.

That is exactly why I always wanted a slab on every floor. However basement & Main floor will be slab, just the 2nd floor will most likely be something else. I know for a fact that a slab is the most efficient, but right after, what is it ? Staple under or panel ?

 

[Paver56]

I built my house 2 years ago. I have radiant throughout. My wife's salon in the basement and my garage have the pex poured in the concrete-very nice. The first and second floor have the pex under the floor. I used wirsbo clips to fasten it. I have hardwood and tile along with a little carpet. It is very nice under the tile and hardwood(engineered hardwood designed for radiant heat) I would say that I really like my system. Under the carpet, although the heat is not as warm on my feet, it still does the job. I would recommend using alluminum plates wherever you can. I put them under my master bathroom and in my kitchen. They seem to hold and transfer the heat more efficiently. It is also important to insulate beneath the tubing. I would also recommend spraying the exterior walls with foam insulation. I sprayed about and 1.5" and them put R13 behind that. It really does a great job keeping the house warm and preventing any wind from making its way into my home.
BTW-I am getting ready to install my new Froling in the coming weeks

 

[bpirger]

I built my place (still in the works) and I have radiant in the slab on the first floor....and someday I will most likely put staple up under the second floor. Last year I installed the Garn and used only the radiant in the first floor slab for heating. Previously I burned wood in the woodstove as primary heat and just maintained a minimum in the slab of 66 or so with oil. So with just the radiant downstairs last year, the upstairs would get a bit nippy....low 60's. So, if I did put the radiant in, I'm sure there'd be no problems. I'd like to pour a lightweight floor myself...still toy with the idea sometimes...we shall see. Most likely it will be stapleup. Extruded, thick panels for heat distribution are key. Graphite panels are available...they should be an even better conductor than extruded aluminum. Panels aren't cheap.... Warmboard looks like a VERY nice product, but I believe it is horrendously expensive....something like 10's the price of a normal 3/4" Advantech sheet. I do believe it would allow for lower temp water however...as likely would the slab. But warmboard would be even lower.... If you look on the heatinghelp.com forum, there are some wonderful examples of the advantages to the extruded plates....

I'd be bummed if there was a structural post right in the middle of the living space I didn't plan. Not sure what your decor is, is it possible to make this post fit in? For example, I have a couple of white pine logs I hand peeled holding up a glumlam beam in my house. They are most certainly a part of the design...I love them. Not sure if you can do something like this....obviously you have thought of this.

It is certainly true that warmer temp water will be required in the staple up, but in my experience, I don't think it would have to be too much. I have R38/R19 and 2800sqft footprint.

 

[Reggie Dunlap]

Also, I'd have a structural engineer verify that the post really is needed.

 

[jimbom]

Also, I'd have a structural engineer verify that the post really is needed.

Bingo.

 

[Fred61]

The original intent is to comfortably heat your living space. I personally wouldn't go through the hassle of pouring concrete on any floor in order to feel a slight difference on my tootsies. About 4 years ago I installed staple up in my circa 70's ranch and have been happy with it. The living space stay's a constant 70 °F . Two years ago I added a mud room/ half bath to the house and since it was over an un-heated basement I decided to go with in-floor heat. Put down 1.5 inch sleepers on two foot centers, laid 3/4" foil faced polyisocyanurate board between them and then laid my own home made sleepers to accept the 1/2 inch barrier pex. (pic below). I then put down 1/2" cement board in thinset and nailed the heck out of it. On top of that went ceramic tile. Nice sturdy floor and warmer than staple-up but still only heats living space. The only one in the house that appreciates the extra warmth in my dog.

Last year I decided to remove the carpet from the second bedroom in favor of laminate. I decided to experiment with the Viega Climate Panel system.
http://www.viega.net/xchg/en-us/hs.xsl/productcatalog.html#modeldetail-group2772655483218
Warm board was out of my price range plus the Viega was the perfect thickness. This coming heating season will be the test for that system. I left the staple-up in place just in case the in floor fails and turns the laminate into pretzels.

 

[Fi-Q]

Well, from you guys comments and everything else I've read in the forums, i guess it's not the end of the world to go with staple up under the second floor. One of the reason I didn't weant to go with it, is my sister in-law use to have a house with staple up underneath hard wood floor and in the cold dry days of the winter, just by looking at the floor, you could almost bet where the pex was stapple underneath, there was more dilatation between the hard wood plank where the pex was running.... Or maybe it was just me that was definetly looking for something....... maybe they were running too hot water, No clue, she's divorce now.... I know engineer hardwood floor is the best, but I want a floor with no VOC in it, and in engineering floor it'S twice the price of regular hardwood, so approx 4k$ extra just for the 1000 sqft of the second floor..... so I will go with regular hardwood.

I did check with the engineer from the firm who sold me the joist and they said the post is needed to pour a slab as I have open floor plan, but I don't need it if I eleminate the slab..... Just to gave you an idea, here's my main floor plan. The post is 14 in from the Kitchen Walk-In, towards the living room. I think my licving room will be small enough as is, I don'T want to cut 14 in in it..... and coming in the house by the Side door (Wich will be use 95% of the time) itMs the first thing you would see looking in the house, is a pst, 14 in from the wall.... in the middle of nowhere.... SO For 2 years I tried to make my mind of living with it... but I was home alst week end, sitting at the main floor, looking at the psot... thinking of still pi** off I still am every dang time I am seeing it.... So I decide I need to find an alternative to it.....