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I’m looking for insulation with a radiant barrier to install over a concrete slab floor and under engineered wood and carpeting. I’ve been in touch with Therma-Float, which produces a product called Therma-Lay (http://www.ghm57.dial.pipex.com ). My difficulty is that Therma-Float is based in England, and doesn’t have a supplier in the United States, or generally supply in the 100 square meter quantity that I need.
Do any of you have experience with this product or something similar?
Thanks for any insights you can provide! Ellen
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Ellen, for radiant barriers in walls and ceilings, I have used a foil paper called "dennys foil". Why I do not know, but it comes in 36" wide rolls, perforated or not.
For solid fixings, there was a product used quite a bit in the 70's called "Thermoply". This was (is) a rigid solid cardboard with a waxed surface on one side and foiled surface on the other side. Sold in 4 x 8 foot sheets @ 1/8" thick. Would make shutters and other insulated shades with it.
I wonder why you wish to use a radiant barrier under your floor. Radiant barriers work best with an air space, usually about 1" between the foil face and heat side of the surface. Are you planing on having your floor float above the slab?
walk good
david
*I am thinking of putting my radiant floor tubing between 1 1/2 sleepers 12 inches on center with an aluminum heat transfer sheeting under the tubing. In parts of the house I would have heard wood flooring on top of the sleepers, The places that I have carpet I would put 3/4 plywood with 1/4 slots between them. My questions are should I leave the tubing loose or staple it? Am I going to end up with a squeaky floor with the expansion and contraction of the tubing on the aluminum? The two reasons I was thinking of going this way verses concert between the sleepers is, I am thinking I can control the heat in the rooms faster and its heard to get concert this time of year in Alaska. Any input on this would be greatly appreciated. Dave
*David,Thanks for your ideas. I am planning on floating the wood floor, but not with a large air space. Rather, I was hoping to get some extra insulation from a reflective layer on top of a support with air pockets (i.e. wood, closed cell foam, etc.) Basically, I'm just looking for an improvement to the 1/8th inch foam that's sold to lay under engineered wood floors.Thanks again, Ellen p.s. I couldn't find "dennys foil" on the web, am I spelling it correctly?
*Ellen,For clarification: you have a concrete slab...non-RFH. You're floating a wood floor on top of the 1/8th inch pad, and the pad will sit directly on the concrete slab?You're looking for some sort of additional insulation to go between the pad and the slab?What's under the slab, insulation-wise?
*Mongo,You're right, the wood floor will be on top of the pad, which is on top of the concrete slab. The slab, unfortunately, is uninsulated.Thanks for any ideas, Ellen
*Ellen, You may consider using one of the newer carpet pad materials. There are several that I have seen that are about 3/8" thick, very dense and firm, much like ensolite used in camping pads. No radiant barrier, but the insulative value would be pretty good for the thickness. I would think you could float your enginneered or floating floor over it without any problem. You may wish to talk to the specific manufacturer to be sure.walk gooddavid
*One thing to be aware of...David already mentioned it in his first post...is that unless the Al face has an air space in front of it, it won't act as a radiant barrier. It will act as a conductor.
*Hmmm...part of my post disappeared into the ether...I tagged on to the end of the above post:If you already have the flooring that you want to float picked out, call the manufacturer and ask them what is needed for an underlayment for THEIR product. Realize that recommendations may change from one product line to another. The tech support is usually helpful, an with an 800 number, it's free.Different manufacturer's have different requirements...which usually means different stiffness or thicknesses in the underlayment.Tell them what you have (uninsulated slab, above/below grade), what you want (floating floor, added insulation, minimal loss of headroom), and what you're looking for (an insulative underlayment with minimal loss of headroom that will work with their product).If the slab is below grade, it will usually require some sort of treatment to prevent moisture from coming through. Not just liquid moisture, but vapor that can then saturate or condense onto the bottom of your flooring.I almost hate to recommend it, but for a below-grade slab it's not too unusual to have to do a layer of poly set in a troweled on asphaltum product. On top of the poly, put down a layer of rigid foam board insulation (RFBI). Polyisocyanate RFBI gives the best DIY R-value bang-for-the-buck at R 7.2 per inch. A layer of one-inch sheets would work. On top of the RFBI, lay two layers of half-inch plywood with staggered seams. Screw the two layers together without allowing the screws to penetrate the RFBI.Then float your flooring (pad and flooring) on top of the ply. This underlayment sandwich will run you about 75-80 cents a square foot for materials...depending on locale.
*Ellen,This product was in another post and may be what you'er looking for.-Edhttp://www.deltams.com/photo/photo_deltafl.html
*Thank you all so much for your help. I finally got a quote on the Therma-Lay of $12 per square for small quantities - too expensive for unknown results. I did contact the flooring manufacturer for the Versastrip flooring we're installing, Universal Flooring (and was embarrassed that I hadn't thought of that myself earlier). They were very helpful and have a product made of recycled carpet, "Quiet Walk", designed as an acoustical underlayment, but with greater insulating properties than their standard underlayment. This sounds similar to the pad mentioned in an earlier post - I think we'll try it.Thank you all so much for your help and advice, Ellen
*There is a product which is touted for use over existing concrete slabs called rFoil. It is essentially foil faced polyethylene formed into multiple layer bubble wrap. They claim an R8.3 to heat flow up, R14.3 down. Here is a link to their site http://www.tvmi.com/index.html
*Dear Jim,Thanks for link. I've seen lots of reflective thermal products come and go. They don't tend to do much. And their emissivity climbs over time as they get dusty or the coatings degrade. As a group, they have proven to be extraordinarily expensive for the given thermal protection.But I do enjoy jazzy commercial websites that go all scientific.Regards, Fred
*FredLOn your "recommendation" I had to checkout that web site.The first thing that I notice is that this is being sold by a marketing company. When you read what they do it is all about marketing and nothing about knowledge of the product or application.For a marketing company they have a very flakey web site.Then you try to find out what "other people" are saying about the product ("3rd party studies) and you find that the ASHRAE report is among the missing.And the other "3rd party study", the Physics of Foil don't have the name of the so called 3rd party that produced it.But you are right, a bunch of nice sounding terms thrown around.