tubing over concrete.ME plz can u help

jonny88

hi and thanks for reading my post.we are renovating a garage into a living space.there is a concrete floor down alreadywhich i dont expect has a vapor barrier.my question is can i lay down a quik track board run my tubing and then finish with a hardwood floor.after reading dans book on radiant he has me worried about moisture thus buckling the floor.would i be better getting a tile which resembles hardwood.mother in law is going to live in there so i cant screw this one up.

Mark Eatherton

Not advised...

Concrete is porous as it pertains to moisture and oxygen.



Although the engineered floors are quite stable, they are NOT water proof, and if exposed to moisture, will swell like a smashed thumb.



As an alternative, they do make a crack isolation shield, which is impervious to moisture transfer. Can't remember the name or brand, but can tell you it is a thick, putty like substance that has to be applied with a shallow notched trowel, then back rolled with a roller brush. It is red in color.



What are you going to do about the back loss of the existing slab (insulation)?



At a minimum, you need 2 times the R value below the radiant panel as you have above it to maintain good control of the direction of heat transfer.



ME

jonny88

reflective barrier?

doesnt the quick track board come with a reflective barrier on it?or should i try a foil wrap under the tubing,now you got me worried,i think i got to go back and read dans book again.mother in law is 65 and her mum is 94.ny winters are getting hard on them.would an alternative be to dig up the whole floor and start fromscratch.again thanks for your input.i will look into the product you talked about.

Mark Eatherton

Remembered the name of the crack isolation shield.

Red Guard. And make sure you are not wearing any good clothing when you apply it. Once on your clothes, they too will be red, and useless.



The aluminum on the bottom of the panel is not for reflection, but is for lateral conduction. In order for reflection too occur, the reflector must have 1" of dead air space on either side of the reflective materials, must be 99.9 % pure aluminum, and must be as smooth as possible. Bubble foil bubble won't do that for you.



If you have enough room to place real insulation (don't worry about reflecting radiant) say 1" thick, and intend to use low R value flooring, then you can pour directly over the insulation and the tubing. If you can't get what you need for insulation in place, maybe you should consider doing radiant ceilings/walls instead.



You have options. Jack hammer surgery would be the last of my choices...



ME

jonny88

thankyou mr.eatherton

thanks for taking the time out to answer my questions.your advice is always apreciated

Mark Eatherton

De nada...

Let us know if there is any other questions you have.



ME

jonny88

another idea.

we talked with contractor and he is building up floor 12" to eliminate a step going into living room to accomodate granmother.so now i can insulate bury my tubing in 2" concrete and then here is my ?they want a linoleum floor.no glue is needed with this .do you think it is a god idea.ceiling height is available.i would love to send you a bottle of scotch or something for your help.if you have a p.o box let me know

Mark Eatherton

Great!!

Some recommendations then as it pertains to that method. If you are going to use concrete, you MUST have a slip sheet placed between the plywood and the concrete. Insulation would be below the plywood decking. Go with R 19 fiberglass insulation.



It is strongly recommended that you create your own expansion joints in strategic places so the cement cracks where YOU want it to, instead of where IT wants to.



Once the concrete it poured, I would suggest you give it a coating of Red Guard crack isolation shield, then the lino product.



Thanks for the liquor offer, but I will pass on getting you into hot water with the USPS. :-)



ME