I WasThinking ..... (Dangerous Thing!)

PhotoGuy

Climate Panel (also known as Quik Trak) is designed with a grove that the pex tightly fits in after a 1/8” silicone bead is put down. What if they made the groove larger and then had the installer place thinset in the groove? The thinset, wrapping the pex, would obviously conduct heat better to the aluminum plates below. I would guess much better than the fraction of pex/silicone that touches the plates they designed into the system. Thoughts? (I also know that there are better systems out there like; extruded AL on top, Warmboard, etc.)

icesailor

I always thought that Silicone (like RTV) was an insulating agent.

Gordy

Thinset is abrasive. Not good for the skin of the pex. there are plate designs which grip the pex with out silicone. That's the difference in plate selection good to bad.

SWEI

There are a number of thermally conductive adhesives available in the industrial world. Generally not cheap.

Thinset is a Portland cement based product. Portland and aluminum do not generally make great neighbors.

PhotoGuy

SWEI: I did read somewhere the same thing about cement/AL. But then it went on to say that it only was a problem when "wet." Once dry, it only had a "1 mil" effect on the AL. They went on to say that if that was a problem, you could always paint the AL first.

Gordy: Isn't pex placed in cement all the time? Maybe you are saying there is difference between thinset and cement being used?

SWEI

Yes, it's the wet/curing time that presents most of the issues. I don't know how much (if any) if fly ash is used in thinset, but that would surely make things worse. I'm picturing trying to squeeze thinset into those little grooves, and thinking it would probably get in the way of some of the contact surface, especially if it's grainy.

PhotoGuy

SWEI: I was also thinking that all the above floor type system have no problem with cement board used directly on their product. As to your latest comment ... I would think with a wider groove it would be real easy to just trowel in. The wider groove would also allow much more cement. More cement = more transfer to plates.

SWEI

Far easier just to get the right plates for the job IMO.

PhotoGuy

SWEI: Well, that didn't answer what I addressed. I said in first post I knew those were better. It's here that I actually got the most information that convinced me of it (Thanks everyone!). I was looking at the Climate Panel before I went to the right side of the fence. Yes, I am convinced. I just am thinking why they came out with this panel that barely touches the aluminum and now see why it fails so bad compared to other stuff. (I do see one advantage - height - but not a problem for me.) I just thought, after reading a bit about gypcrete, that it would have made a great transfer agent in their groove. Was surprised they didn't use "something" other that silicone. I admit I know little (see title) about this. Stuff (questions) pop in my head and I ask - best way to learn! My goal is not to piss anyone off here - just learn. Yea, in the end I'll probably go with the plates (depends on what expert draws up) but, in the meantime, I like finding out the "whys" when hings work better or not.

icesailor

Its the lime in the cement on the aluminum. Not the other way.

Ever see aluminum flashings on a chimney? (Not for long you won't)

Gordy

Yes pex is in concrete all the time. Now let's stop and think about this in an installation manner. I'm talking about during installation trying to force tubing in to channel with an abrasive material.

Your slobbering thinset into grooves trying to either get just the right amount, or hoping it will squeeze out the excess, and seat firmly in the channel. Ever work with thinset? Now do this neatly over a large SF. Area. It ain't gonna happen.

To be efficient in installation you would need another guy mixing very small quantities because the thinset starts to stiffen as time goes by to the point it's no longer useful small window of opportunity.

Later that thinset starts to crumble unless you use a polymer based type. Still it's so thin that there is going to be basically granules left after time.

To me there is no return for the PIA it would cause. Forget it.

Gordy

I did this very thing for an over the top self made sandwich panel. This was for floor warming only since I already have radiant ceilings to cover the load. I used type L 3/8" soft copper tubing 8" oc. Back when copper was still cheap.

When laying the hardie backer I filled all the grooves with thinset as I laid the hardi backer which requires thinset before laying board down. I can tell you the heat spread is very nice. But the grooves allowed for a decent amount of thinset to encompass the tubing.

PhotoGuy

GORDY: That all made sense - Thanks!

A few more questions come up:

1) icesailor, you say it's the lime in the cement - don't know what you meant by other way around? Also, does the Hardi-Backer or cement board stuff not have lime in it? I'm just wondering why manufacturers of above plate AL allow their stuff to touch it then.

2) I always wondered about the silicone they use when putting in the pex. What's up with that? If it transferred heat then why not fill the groove (slobber it up) with more that 1/8th inch? Is it there not because it transfers heat but just keeps the system silent?

3) Copper was at one time cheap? (I'm so old I can't remember) (Those were the days, if I only knew ....)

Snowmelt

Photo guy, are you trying to be a radiant floor engineer?

Gordy

I should of said a lot cheaper than today's prices.

PhotoGuy

Snowmelt: NO! Just find this stuff real interesting. I was just out blowing snow and the lady next door (single) was unable to start her blower up. Unable to get it going for her I just did the thing for her. She's a science teacher for the next community over so I asked her about the cement/AL thing and she had no clue. I filled her in - I felt smart! Is that not a good thing? I'm retired and have the time so I am on a search for knowledge! I was never like this in school (in my young days) so I'm really enjoying what I'm learning. I'm getting the impression that maybe I'm asking to much or I should be an engineer/installer/designer to be on this board. If so, please let me know and I'll take off. I just read something and I get more questions and figured this was the best place to go and ask. (I also have a bit of distrust from non-professionals and companies trying to sell product.) Something as simple as knowing AL & cement don't mix I never knew. I can see where that would help if I ever needed to do a roof repair.

Gordy

Your fine. These discussions are nurishing.

Thinset is not as aggressive as concrete. The aluminum will oxidize during the curing process a little, but that's about it. There is a lot more thickness in a plate than step flashing....well some plates. Copper is fine with it to. All though the copper won't oxidize. At least min did not.

PhotoGuy

Thanks Gordy!

Haha, I just literally so a spot on tv a minute ago where they said there is a "beer can" house in Texas. I Google'd it and saw a picture of how he has beer cans in cement. Ouch - from what I just learned, he's in for long term trouble!

Gordy

That's how you make a honey comb.

PhotoGuy

Nice.

Any thoughts on the silicone? I'm thinking it was there for noise - not heat transfer. I'm not sure there would have been noise from the way the product was designed. The pex had no where to expand, and if it did, pex rubbing wood certainly wouldn't make noise. I can see where noise would be a problem with the cheap stamped AL. And, if silicone was a good heat transfer all these companies would be using.

BobC

RTV is electrically isolating but it conducts heat a hell of a lot better than air does. Almost any medium is better than air or worse yet a vacuum when it comes to thermal conductivity.

Bob

KC_Jones

I am sure there are all types and compositions of silicone, but think about this I have a bunch of silicone mats in my kitchen that are used to insulate the heat of a hot pan from the counter top. Knowing that I personally would shy away from silicone.

RobG

On Quick Trak the aluminum is on the bottom. It snaps in and the only contact with the aluminum is on the very bottom of the pex. If you buy the caulk from Uponor it is a siliconized aluminum caulk. It is gray in color and contains aluminum particles for heat transfer.

PhotoGuy

RobG: I have heard that but I had previously (3 days ago I believe) checked it and was surprised with my findings. I looked at the “Submittle Package” (LINK – page 10) and it has the caulk listed as a “… single-component, moisture-cured silicone rubber.” Their install manual (LINK – page 28) says that “Groove Tube” is strongly recommended. It then says, “Do not use anything but 100% silicone rated for 180F,” and “Do not use caulking or any other type of sealant or adhesive.” (* This was for Climate Panel but my understanding is Quik Trak is same stuff.)

Gordy

I think it's a mountain out of a mole hill.

PhotoGuy

BobC and KC_Jones: I am agreeing with both of you! I'm of the thinking that something is better than straight air. On the other hand, silicone ain't doing much to help. I looked up (LINK) "thermal conductivity" of some of the stuff we're talking about here and found this:

Cement, Portland = 0.29
Cement, mortar = 1.73
Concrete, lightweight = 0.1 – 0.3
Silicone cast resin = 0.15 – 0.32
Aluminum = 205
Plywood = 0.13
Sand, dry = 0.15 – 0.25
Sodium = 135

I guess there is something there for the silicone but not much! I am surprised by the sodium - what's that about?

SWEI

http://www.dowcorning.com/applications/search/products/details.aspx?prod=02507544&type=PROD

PhotoGuy

Gordy said:

I think it's a mountain out of a mole hill.

Ouch. I thought this stuff was nourishing.

Gordy

Power screeds for concrete are made from aluminum, and magnesium exclusively. Enough about that too. Never seen one disintegrate.

icesailor

Too much to cover.

Portland Cement, sand, gravel and water sets and cures in a chemical process of hydration. If you have a concrete walk way, once all the moisture has left the slab, it is as hard as it will ever get. Unless it gets soaked by water in a rainfall or irrigated on. Every time concrete gets wet, it gets stronger. Forever I am told. The Romans figured it out. Roman concrete that is 2,000+ years old, is as strong as most basic concrete mixes of today.

Hardee Board and other cementous tile board hydrate until they dry. Once wet again, they start to hydrate again and get stronger. I started off carrying the brick and block. I guarantee you that not a one of the people I worked for had a clue about this. Just that it had the right consistency.

http://en.wikipedia.org/wiki/Portland_cement

http://en.wikipedia.org/wiki/Roman_concrete

PhotoGuy

I'm guessing that the stuff they sell is the Dow Corning stuff and they mislabeled it incorrectly in their own stuff. I'm surprised they let you use the 100% silicone as an alternative. You would think they want the Dow stuff used in lieu of their's if needed.

Gordy

icesailor said:

Too much to cover.

Portland Cement, sand, gravel and water sets and cures in a chemical process of hydration. If you have a concrete walk way, once all the moisture has left the slab, it is as hard as it will ever get. Unless it gets soaked by water in a rainfall or irrigated on. Every time concrete gets wet, it gets stronger. Forever I am told. The Romans figured it out. Roman concrete that is 15oo years old, is as strong as most basic concrete mixes of today.

Hardee Board and other cementous tile board hydrate until they dry. Once wet again, they start to hydrate again and get stronger.

Fly ash mixes change that ice. A straight Portland mix reaches peak strength in 28 days rather, and rather quickly in initial 3-7 days. Fly ash mixes all though do not reach higher strengths in shorter durations will climb well past Portland mixes after 28 days. There are so many mix designs out there make your head spin. Yes hydration is key. Water is concretes best friend until it freezes.

Gordy

PhotoGuy said:

Gordy said:

I think it's a mountain out of a mole hill.

Ouch. I thought this stuff was nourishing.

To a point.

PhotoGuy

Apologies. I'll try to find another place to get answers. Thanks much for all the insights I got from everyone and putting up with me. If I was young, yea, maybe I would say I'm trying to become a radiant floor engineer. Bit jealous as I do find this interesting. I was a cop for 31 years (about 20 too many!) and now retired. Guess I missed out - this sure looks like a cool (no pun intended) occupation. Good luck to all of you and stay warm (pun intended).

Gordy

Come on don't take it personal we like you. Don't go.


And thank you for being a law enforcement officer. I know that cold not have been an easy 31 years.

RobG

I think that I have a few tubes of the caulk provided by Uponor for Quick-Trak in my shop. I will dig it up and see what it is. It's been about 15 years since I did my LAST Quick-Track job. It's just too much work to put down those small planks.

Gordy

If it's that old it's toast throw it out.

RobG

I don't want to use it, just see what they supplied at the time.