Insultarp Questions

chuck shaw

The job is slab on grade, was baseboard, the homeowner wants to do radiant. He asked about laying down insultarp (or a similar product.) I have never used it.

What my questions are, 1) What is the R value (or does it vary with manufacturer) 2) How thick is it? (or can you different types) 3) Doing a retro-fit slab on grade, what type of installation method would be best? I am thinking my options are, lightweight (or concrete) overpour, panels (such as quik-trak), or sleepers. If I do sleepers, would I have any real gain, from plates, even if I cant attach them to the sub floor, or would this be a case where the only option would be not using plates. Also, the current slab is not insulated

My first choice is to go with an overpour, but what I want to do, and what the homeowner wants may not be the same. I dont believe he took overpour into account when framing. So the next thought would be trak panels, then suspended, with or without plates.

Any feedback, about any of the above methods (as it relates to insultarp), would be most helpful. The plate debate has already been covered.

Chuck Shaw

hr

I's say an honest

R-2.5 for InsulTarp as it is only a 1/2" thick of real product. I have found it performs real close to 1" foamboard, and the vapor barrier and 12X50 foot rolls really speed installation.

What kind of loads in the basement, heatloss calc?

Overpour would be simple, install tarp, mesh, tube and pour. Going to need 1-1/2 to 2"

Gyp is often called a lightweight concrete, this is not true. A real lightweight concrete is made with special aggerates or sometimes foam beads. Not a great radiant product however. Much lighter than gyp. I'm not sure you need light weight for an overpour?

Concrete is a better conductor than gyp mixes. Gyp levels uneven floors better, although i have never installed gyp over InsulTarp, that makes me nervous

Sleepers and transfer plates is another choice depending on final floor coverings this may be a good option. if tile is the final covering you would need to add CBS's to the top. more labor and expense. More labor involved with sleepers or ply fastened to the floor also and if moisture is ever a concern, think I would still favor an overpour.

Even the thin retro on top products would benefit from an insulation of some sort below. don't think any tarp product would work well under QuikTrac type of products.

With a thin concrete pour beef up the fiber mix ratio for additional crack resistence and spread.

Read this article


http://www.pmmag.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2379,116124,00.html

hot rod


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chuck shaw

There is no basement

so there is no load to deal with there. Slab on grade. I got to thinking about it, and if he doesnt have room for any type of overpour, he probally wont have room for sleepers either.

I havent been over to look at the job yet, so I am not sure what the loads are. I wanted to have some information before I went to look at things.


Chuck

hr

Right slab, wrong grade

sorryt i didn't read that right The thinnest on top would be the Wirsbo Quik Trac. Still be nice to get some thermal break as the aluminum transfer sheet will contact the slab conducting heat downward. How much, and how long depends on the final floor covering R- value.

Maybe the 1/2" Trac with 1/4" insulation?

If they want radiant bad enough there is always a way! Remember Foley's "groove the exisiting slab" job! Didn't cost him any floor elevation increase! Maybe he would come over and groove your slab job.

hot rod

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Unknown

height

overpours are typically 1.5" minimum.
Dry systems weigh in at 3/4" typical height.
Quik Trak is 1/2" but as HR mentioned you'll want a thermal break in this case so you lose the height benefit.
If floor height is the problem, maybe ceiling is an option?

More than just sleepers, I would use the "sandwich" method which is pretty much the same, except your sleepers are 3/4" plywood or OSB cut into strips with a 1" channel at 8-12" on center, using aluminum plates of some kind on top of that plywood and the tubing in the channel. This gets the aluminum over the thermal break of the plywood so as long as your finished floor is R1 or so (wood/tile) you should have decent output. If floor height were less of a concern 1" of EPS with a 1.5" overpour is nice too.
_______________________________

Northeast Radiant Technology, LLC

Robert Brown, Co-Owner

NRTradiant.com

Dan Foley

No Thanks

Nice try, Hot Rod! Thanks, but no thanks. My concrete grooving days are over. -DF

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chuck shaw

Thanks Rob

that method had sliped my mind, I knew there was a way to use plates,

Thanks for poking me in the brain

Chuck