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My local radiant floor rep is promoting the use of a double bubble wrap insulation with a radiant foil barrier for insulating existing concrete slabs. It supposedly gives an R10 insulation value in a 1/2″ thickness. The product can be see on the web site at:
http://www.tvmi.com/rfoil/
Has anyone had any experience with this product or similar products in radiant floor applications? What is the Thermography method for determining R value?
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Jim,
My plumbing supplier suggested the same product. Sounded great, but if you're pouring a floor over it you may want to speak with that contractor before buying.
The guys who poured my Maxxon Thermofloor said that stuff can be a real pain. The bubble wrap tries to float up into the pour so it needs to be secured on a first pour and then a second pour completes the job.
I used Dow blueboard, an non reflective extruded foam with a mere R-3 which the Thermofloor guys said is more than enough.
If this installation is over a wood floor I would suggest you put the reflective insulation under the subfloor from the basement/crawlspace side.
Craig
*Thanks. My rep said the same thing about the stuffstendency to float. It is over an existing slab and the 1/2" thickness appeals to me to avoid raising the floor too much. Blue board would be 2 inches for the same R factor.I'm thinking of shooting, with Powder actuated fasteners, clips for the tubing down thru the rFoil. this would secure the stuff and laying my mesh reiforcement over it will further hold it down.
*Double sided carpet tape? Along the each edge of the ailvery bublewrap stuff. It's definitely preferable to insulate between the old and new slabs. The new, heated slab will be more responsive than if you combine the two.If by "mesh reinforcement", you mean 6" x 6" #10 welded wire fabric, that should be installed in the middle (vertically) of the new slab. Not that it ever is - it often starts at the bottom and/or gets stepped on during the pour. But the will be stronger with the WWF in the middle which can be done by elevated it on dobbies or (and this is particularly sketchy in a thin pour) pulling it up with a claw hammer as workers move out of each area. For a thin pour, the tubing at the bottom with help keep the WWF up a bit. -David
*Thanks again. Yes I meant WWF when I said mesh. I originally posted to see if anyone had any experience with this product. I'm somewhat suspicious of radiant foil insulation claims. The bubbles on both sides of the foil are supposed to provide an air space to allow the radiant reflection insulation effect. Does anyone know where I can get infor on the "Thermographic Method" of determining R-Factor. I can't find it at the ASTM site.
*"Thermographic" sounds like infrared temeprature sensing - a very quick and non-contact way to read a surface temperature. I got my mine for $65 and find it useful for checking radiant floors, duct temps, etc.R-10 does sound like a lot for 1/2" of bubble wrap and tin foil. And the wording wasn't exactly "R-10" but the "equivalent of R-10" or some such. So maybe they are counting the air films on each side (like those scumbag window manufacturers do) and the radiant foil effect on each side - which is only valid if there is air space on each side. Not if one side pressed against the soil and the other side has concrete all over it. At least the radiant foil WITHIN their product ought to have some benefit. But maybe sound be described as R-4 or R-5 in that application. -David
*Yes, thermographic sounds like an IR technique. I have also had an IR thermometer for many years. When I think of what I paid in '92 vs what they sell for now I kick myself but it has paid for itself many times over. I use it when surveying electrical equipment for loose connections, partial grounds bad outlets and switches. Probably prevented many fires.Problems with just reading the surface temperature ...Did they calibrate to the emissivity, surface of concrete or surface of insulation, how was the back surface temperature measured. I think, unless there is an ASTM method this is fraught with error sources. Regardless I think I'm going to use it, maybe bury a thermocouple for curiosity.
*Jim....I have used the bubble wrap stapled to the bottom of floor joists...Under concreted it would be way cheaper to just get shipping bubble wrap. The foil will do nothing if not exposed to air so they who say say...I bet the r factor would be .25 for the single bubble and maybe 1 with the double bubble...Use a layer of the least expensive foam for a thermal break...we have available a used foam dealer...sells all foam boards semi broken and such for half price.near the stream,aj
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My local radiant floor rep is promoting the use of a double bubble wrap insulation with a radiant foil barrier for insulating existing concrete slabs. It supposedly gives an R10 insulation value in a 1/2" thickness. The product can be see on the web site at:
http://www.tvmi.com/rfoil/
Has anyone had any experience with this product or similar products in radiant floor applications? What is the Thermography method for determining R value?