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Underlayment with metallic foil layer: Worth it?


Aqua123's Avatar
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08-31-13, 12:40 AM   #1  
Underlayment with metallic foil layer: Worth it?

Has anyone used underlayment with that reflective insulation layer (metallic foil)? I am installing 12mm laminate on concrete slab and the room has it's own gas fireplace. I was wondering if it would actually do any real heat reflecting through the 12mm of laminate.

 
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08-31-13, 02:29 AM   #2  
I've never used any underlayment with a reflective foil on it. You may want to give us more information on the type of underlayment you are considering. I would caution, however, to use whatever underlayment your flooring manufacturer suggests just to maintain warranty.

 
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08-31-13, 04:49 AM   #3  
I have used this on a slab, the foil turns the underlayment into a vapor barrier as well and is recommended for use over concrete. It is not designed to reflect heat. Use duct tape on the seams.

 
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08-31-13, 01:33 PM   #4  
There is no warranty in this case, used laminate.

 
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08-31-13, 01:37 PM   #5  
Weird, the big box store brand of this stuff says the layer is "thermoboost". Or, maybe I just assumed that's what it was.

Quote from their description:

Excellent over radiant heated floors, reflects 97%
Use over concrete and wood substrates above or below grade
Install so foil faces up

 
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08-31-13, 02:02 PM   #6  
But you don't have radiant heat. All you have is cold concrete with nothing producing heat to reflect. USED LAMINATE?? Oh, take me now!!!

 
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08-31-13, 04:24 PM   #7  
That was kinda mean... yes it's used laminate not all of us have thousands to spend on renos. I got a deal on 12mm laminate in great condition, which is just fine for the application. It's replacing bright red nasty carpeting so it's going to be a big upgrade.

Reflective foil is pretty simple, it just reflects heat back.... the room is separately heated with a gas fireplace, so I thought it might help to hold in some of the heat. People use this stuff in walls and whatnot so why wouldn't it work in floors? I just think the benefit would be negligible due to the thickness of the laminate/underlay already doing the same thing.

 
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08-31-13, 04:48 PM   #8  
I used 1/2" rigid polyisocyanurate one side foil faced other side black plastic between a concrete slab and floating 3/4" T&G plywood floor. It has an R value around 3. I also painted the slab with Dryloc before laying the sheet goods.

 
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08-31-13, 06:11 PM   #9  
It definitely wasn't intended to be "mean". I ain't that way. Laminate is not my preference at all, and "used" laminate will introduce more problems if it is click lock. I just want you to be aware of potential problems.

 
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09-18-13, 04:10 PM   #10  
I was thinking of putting a radiant barrier (reflective) insulation on top of concrete sub-floor and under a floating floor. Some of the foil companies are giving me opposing opinions.
Did it work to make your floor warm?

 
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09-18-13, 04:14 PM   #11  
I was told by one reflective company that unless there is 3/4" of airspace that there will be no insulation provided. I want to put it on top of a concrete slab (was also told that the part of the reflective material that touches the concrete will disintegrate over time due to the lime in the concrete. Yes, it is supposed to reflect heat back up, as long as there is an air space and it is not in direct contact with the floor itself?

 
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