Icynene with plates

Troy_3

We have been involved in these. I agree the foam works great but never against the plates. That stuff sneeks into every crack and crevice. It will surely get under some plates and that is not where you want insulation of any thickness. The tube bends also get completly insulated when sprayed. We've even had a contractor just staple rosen paper over the tubes and then spray the paper. It is cheap and quick and easy. Anything to keep the foam from going between the emitter and the desired heat flow.

MikeB_2

Icynene with plates

I am in the process of insulating my house with Icynene. I was planning to put batts under my radiant install (with plates), but since the Icynene contractor is on-site, I am thinking of having him spray right over the plates. I read on this board that tha 2" airspace is not required with the plates, but was wondering if anyone has done this and what the results were. Any chance the icynene gets in-between the plates and prevents the plates from heating up? Any advice would be appreciated!

Ken_40

If your using...

"engineered" joists, there's a "natural" lip on the upper nailer that affords near perfect spacing to fit 1/2" or 1" foil faced rigid insulation to. If installed with press fit or tacked with a roofer every 5 feet or so, an overspray of Icynene is incredibly efficient and among the best designs on the planet for staple up IMO.

DO NOT spray the Icynene directly onto the plates! Despite the huge R-value of Icynene, it will still act as a "sink" if directly apllied.

Just be sure to seal the bay-ends well and Icynene that "non-contact" area of the bays with as much spray-foam as you can to seal against both thermal as well as infiltration elements.

Sounds a lot like the designs we used on my northern VT home. My fuel bill is cheaper than my IPS (:-o)

GW

heat sink?

I'm trying to lear about foam, this is a new concept to me... the foam has conductive qualities? I've talked with one smart euro-heat guy (actually in VT) that this method works beautifully. Thanks for your thoughts.

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hr

I've done 4 jobs with foam

sprayed against the transfer plates.

Check with the product manufacture for temperature limitations.

However, those spray foam guys think like the bubble foil guys! They try to tell you 1/2" performs like R-19. Don't believe it. You want at least 4" of sprayed foam in my opinion or you will get downward leakage.

That does get costly, however at increased thickness.

hot rod

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Ken_40

Gary,

1) I hope the VT guys is not the one I suspect it is! His designs are based on selling the most product to as many hacks as possible in the shortest period of time possible - and maximizing $$$, not making homes energy efficient, or comfortable.

2) Spraying the plates directly with foam will induce conductive losses. True, they may be minimal, but the foam referred to is incredibly effective at sealing chinks and reducing infiltration to the lowest possible levesl. Its R-value is also great, but like FG, direct contact becomes a "sink" and would be better designed in the manner describe in my post above: ~1" daed air barrier between plates and next layer below them. The reflective properties of the 1" rigid foam board and THEN spraying that cavity/bay is the best of the best.

True, FG, foam or anythung else for that matter will detract from the sub-floor heating via convenction and radiation, but the transfer of energy via conduction is legendery; by any other means - virtually insignificant - in this instance.

The element of direct contact of ANY material to the underside of the plate will induce conduction. The objst being to have as much heat as possible radiante by conduction into the flooring material above is paramount. Anything that dynamic, diminishes performance, regardless of "by how little." IMO

MikeB_2

Foam on plates

thanks. Hot Rod - is there any concerns about the foam getting "under" the plates? I used heavy duty ones for 80% of the job which I don't think would allow the foam to get under, but part of it has the thinner ones that do have gaps between the pex and the plates.

Ken_40

HR,

If you had the option of leaving the natural void from the joist "flange" as an air cavity, then faastening 1" foil faced ins. board snugly to the flange and filling the reamining bay with foam: OR, spray foaming directly onto the plates - which would you prefer?

I tried both foam on FF rigid and the ~2" air void w/plates, AND 12" FG insulation agaisnt the 1" ff rigid. The R- values are so high the cost drove the factor - and we opted for FG!

About 1/6th the cost of the foam.

Agreed, the infiltration factors of foam are undeniably the best. But, when dealing with one a.c per 12 hours...

GW

nope

not the same people; this dude is an installer, I visited one of his jobs with Viessamnn vitodens and solar. Shawn is his name.

I now better understand you point. Yes, I know all the basics. Fiberglass is the rear end of true building performance. Foam, being much more expenside should be used mindfully to keep costs realistic.

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hr

I would most definately

use the spray foam to do the rim joist or box joist detail. This is where the infiltration is greatest at the gap prone plate to concrete wall connection.

I'm not convinced foil faced anything adds to the heat transfer. My experience shows it just dusts over rendering the foil usless for energy reflecting.

I-joists do make the installation very easy.

With the transfer being conduction powerful, with transfer plate installations, I don't know the air space adds anything, but why not. It offers some convection potential.

I do like the air space with foam below. As long as the ends are sealed, but that has to be an expensive build up.

I do HATE exposed fiberglass batts however cheap and R value-ish they may be.

hot rod

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Paul Formisano

Icynene under plates

One thing to remember about icynene is that it's an open-cell foam, so it can be/get damp - I imagine it would act as a heat sink then...

Unknown

Shawn Newcity with Gastech? If so, I've talked to that guy, he knows some stuff for sure.

ALH_4

conduction

I have to disagree with point 2, but I do think it would help reduce striping by allowing some convection to even-out the floor temperature. I also have concerns about foam getting between the plates and the subfloor.

I would certainly never recommend keeping foam off the back side of your wall sheathing because of conduction. Same thing. I don't think conduction is the problem with spraying plates directly.

Question: Why is Ultra-Fin natural aluminum finish if flat black would significantly improve its output? have they done testing on this?

Unknown

I'm on the fence with it myself, but I do have to note that your wall is not a higher than room temp heat emitter, and the plates are. Removing "conduction" from the wall just gives you a vertical airspace which will convect and lessen any benefit from the dead air.

In a joist, with higher temp plates, I could see the arguement for a small airspace.. conduction is strongest, after all.. and with the plates up top, it's a true dead air space, no convective loops.

But.. not sold. Airspaces are only figured as about an R1 for up to a 4" airspace. So that may indicate it's not quite so clear cut.. if you have a 1" airspace acting as an R1, you'd be better off with the R3.6 of icynene. But, I'm not sure how the radiant/convective vs conductive transfer rates are figured into those Rvalue assumptions...

I'm open to a more rigorous arguement either way though. Ultimately I'd wager the difference is small.

ALH_4

air space

I agree that the difference is small. Also the R-Value of air space I have seen is for a vertical air space, which as you stated, will behave differently than a horizontal air space.

I do think the wall could be a very hot emitter though. It could also be very cold. Those dT's could be much larger than the plate vs. room temperature.

Another question: Does it matter whether the air space is above or below the foam?

Unknown

How would your sheetrock inner face to insulation dT be higher, or even close to your heated plate to insulation dT in any circumstance other than a directly heated wall? I'm not sure I follow your thoughts there.

That follow up question is intriguing. I suppose it shouldn't matter, if you are breaking conduction/adding air Rvalue at any point in the assembly, the the total construction of that assembly should be identical whether the airspace is above or below any particular element of the assembly....?

ALH_4

Walls

I was thinking the other way around. The temperature of the outside of the wall could be very high or very low, similar to the floor surface. I guess I was thinking that would be analogous to the floor assembly.

hr

If the foam can get between

the plate and the subfloor, then it wasn't tight to begin with. Hense less conduction transfer.

I noticed my last install of ThinFin over 4800 feet.. I had a tough time getting the roofing nailer or the new Senco stapler to shoot through on every shot. A lot more bent nails and bounced staples then my previous installs.

I wonder that the temper got a bit too hard on this batch.

I will say, since these were pre-punched, that zip screws, even every other hole pulled them much tighter to the floor than the air tools. Both the nail gun and stapler dimples the contact side and actually pushes the plate away a bit.

That would certainly invite expanding foam into the party and spoil some fun

I just wish I could find a quicker screw gun to use overhead that didn't weigh a ton!!

hot rod

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ALH_4

plates

The Grabber guns seem to be the best it gets, but the bits die early deaths and there's nothing that tires your shoulder like installing 5000 ft of original ThermoFin with them. I cannot imagine what a pain it would be to try to hit pre-punched holes. Time is of the essence when installing this stuff. I will agree the pneumatic tools don't do quite as nice a job as the screw guns. Not that pneumatic tools do a bad job, but being able to snug the plate to the subfloor is nice.

I agree that it seemed that sometimes the temper or the alloy or something was a little off. As the extrusion dies wear, the tube gets tighter in the channel too. I remember thinking the stuff from the current supplier was not the same as the one prior when they changed over. It seemed incredibly difficult to get all the details worked out.

I always thought uniformity should be very easy to achieve with something like aluminum in a construction environment. Relative to the wall studs, the plates are precision equipment. However, when installing tens of thousands of feet over a period of years, the small differences are pretty obvious.

I have no idea what Uponor is doing with their plates. I wonder if they have changed suppliers since they acquired RTI. Do they seem to have been consistent throughout the years?

Troy_3

stapling plates

Hotrod: we noticed the same thing. We have two staple guns and neither one would staple the plates on our last job. I thought maybe the staples changed. I don't get it. It really slows down the process to screw them up. If anyone knows the answer I'd love to know. I have a couple jobs coming that I dread. Thanx

hr

hot staples down your shirt

is what you get when they fire back. Good eye protection and a tight collared shirt

What we ended up doing it trying to get one staple leg in the plate and the other in the subfloor. It helped a lot but slowed down the process and took careful aim.

I do think the zip screw every 2 feet holds them tighter than the staples or nails shoving them away.

On a recent small job I used the lightest cordless I own 14V and a pair of "SilverBack" magnetic gloves to keep a supply of screws at finger tips.

hot rod

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GW

yes

That is the dude.

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ALH_4

staplers

May I ask which model stapler you use? When some of the staplers get older they lose some of their ability to drive the staples through the aluminum. I like Hitachi N5008AC staplers.

hr

A fairly new

SNS45 XP! and two Makita coil roof nailers. Both with Senco brand "bullets"

I even tried out the SNS on the original heavy gauge ThermoFins before I bought it.

Both the new stapler and the old Makitas worked fine for years.

I even blew the head spring off the Senco due to all the fire backs.

hot rod

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hr

Foam on a metal \"span-deck\" radiant

this is a shot of the foam sprayed on the basement ceiling. The floor above has radiant in a 4" pour on metal decking. I'd guess 2-3" worth of foam in this shop. Floor above was running 83-85F

hot rod

Ken_40

Avantec sub flooring

is like concrete. Thwe resin binder is not gun-stapler friendly.

We found the solution to be a "slap stapler" worked best - but not without some serious arm weariness):-o(