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Can someone talk me out of electric radiant floors

lkhelp
lkhelp Member Posts: 26
edited September 2021 in Radiant Heating
Hello,

   We moved into a house in Massachusetts 9 months ago. It’s on a concrete slab which is pretty unusual for the area. Redid floors in kids bedrooms and went with engineered hardwood. And I can’t stand how squeaky they are! Now we will be redoing tile in the kitchen and I had this crazy(?) idea to put electric radiant floor in the kitchen for comfort (main source of heat is baseboards). And then even crazier one - why not put tile in the bedrooms as well? Does electric heat for comfort cost a lot? Is a lot of energy wasted into heating the concrete slab?

Thank you in advance!

Comments

  • Yes, I believe that heat will be wasted downward into the slab; hard to say how much as it depends on the slab/insulation/soil type. I’ve been taught that downward movement of heat stabilizes after time and that most of the heat will then move upward, but have no empirical data.  
    A cold slab floor is very unwelcoming, especially in a kitchen where I spend a good part of my life. To me, it would be another kitchen appliance that has a monthly subscription fee. 
    Often wrong, never in doubt.
    Zman
  • Jamie Hall
    Jamie Hall Member Posts: 18,957
    My first comment is... engineered wood floors, if they are laid correctly, shouldn't be squeaky. Something went wrong with the installation.

    OK. That said. The main disadvantage of electric heat -- radiant floors, baseboard, whatever -- is running cost. In this instance, it appears that what you are intending to do is to put electric radiant heat under the new tile in the kitchen -- but not depend on it for your primary heat source. That works, and you can always switch it off if the electric bill gets to be too eye-watering!

    I would be kind of surprised -- unless this was a pretty high end build -- if the slab had either bottom or perimeter insulation. This means that yes, heat will be lost too the slab and the great out of doors. If you had a lot of headroom, you could put insulation under the electric heat and the tile, but to make any difference to speak of you'd lose two or three inches of headroom, and that could be a real problem. I wouldn't bother when you ae using just enough heat to keep the floor warm and not trying to heat the space that way.

    I wouldn't care for tile in a bedroom -- to me it would seem cold and uninviting. But that's just me.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Zman
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 12,010
    Radiant heat of any kind (especially electric) will be expensive to run if the slab was not designed for radiant heat.

    That being said with a house on a slab even one not designed for radiant heat I wouldn't be against adding it in a bathroom or kitchen to make the space more comfortable.

    But I would not use it as my main heat source, just as a booster
  • pecmsg
    pecmsg Member Posts: 2,898
    If your just trying to take the chill off that slab then do it. If the costs are too high you can always shut it off.

    I agree with @Jamie Hall Properly installed engineered wood floors don't squeak!
  • STEVEusaPA
    STEVEusaPA Member Posts: 5,689
    The title of your thread should read, "Can someone talk me into electric radiant floors."
    steve
  • PC7060
    PC7060 Member Posts: 712
    What type of electric radiant floors? Something like Schluter Ditra Heat under tile?
     
  • jumper
    jumper Member Posts: 1,843
    Replace hard tile with comfy linoleum or vinyl.
    Softer and less cold.
  • JUGHNE
    JUGHNE Member Posts: 9,765
    Most of our house is ceramic on wood or concrete.
    For the kitchen we decided on full thickness oak flooring, reasoning that tile, even on wood, is like walking on concrete all day long.
    Also any dish dropped will be in pieces, with the wood it has a chance of survival.
    There is some vinyl that is "cushy" on the feet and the china....also warmer.
  • Larry Weingarten
    Larry Weingarten Member Posts: 2,549
    Hi @lkhelp , Is there room to install some thickness of foam on top of the slab before doing the rest of the flooring? Maybe 1.5"? If so, electric radiant might not be so unfriendly to your wallet. Then go with linoleum or vinyl flooring material as @jumper suggested as this will minimize the total height of the floor system.

    Yours, Larry
  • lkhelp
    lkhelp Member Posts: 26
    Thank you very much all for the advice!
    To address few points:
    - Yes, the chances of the slab being insulated are pretty slim. The original portion of the house was built in 50s and the addition (where half of the kitchen is) in the 90s
    - There is not much room to add to the height, trying to be as low profile as possible - and that's the reason of not going with hardwood (no room for plywood under it)
    - Fully agree that properly installed engineered wood floors should not squeak, I can rant for hours about the installers we used. First they didn't level properly, then when they redid part of the job the removed some bounciness, but introduced a lot of squeakiness
    - Any advice on brand/type of electric radiant heating floors to use? Totally new to this.
  • eauciel
    eauciel Member Posts: 3
    I agree with those who suggest that a proper radiant heat floor requires a properly insulated slab, even an insulated footing. Lacking that, I would rater install a cork floor than electric heat under tile. 
    Cork is comfortable to bare feet and dropped dishes. Feels warm. Doesn’t squeak. Replace worn sections easily after a few years.  Initially expensive. No operating costs. 
    Alan (California Radiant) Forbes
  • psb75
    psb75 Member Posts: 570
    The cork floor idea is great for this application. Consider it. eauciel is 'spot on.' Cork is BOTH the floor and the insulator!
  • bill_brooks
    bill_brooks Member Posts: 49
    as an alternative to under floor heat.....
    i owned a 6 unit apt. bldg. that used IN-CEILING electric heat. the feeling you got coming in on a cold
    winter day was delightful. the tenants loved it. of coarse the bldg. was designed for it. which meant 9"
    of poured rock wool on the attic floor above the living space. but this could be retro'd with attaching rigid
    foil-faced insulation to the existing ceiling. depending on lighting,etc. it shouldn't be too difficult. the walls might even be considered as another source. naturally the new dead loads on the ceiling joists would have to be considered. all doable depending on bldg. construction.
  • jimna01
    jimna01 Member Posts: 19
    At the price of electricity in New England you couldn't pay me to put in electric heat. Currently I pay 8 cents per Kwh for generation and 13.9 cents /kwh for distribution and 2% of that for taxes and fees. So 22 cents per kwh. No way does any form of electrical resistive heat make sense. Maybe a small radiant heat system in a bathroom for comfort .
  • Pat_11
    Pat_11 Member Posts: 47
    In Massachusetts I wouldn’t use electric radiant as the primary heat source because of the operating cost. But it in your case it is a great solution for floor warming. Use a thermal break under the electric radiant.
  • DavidDow_2
    DavidDow_2 Member Posts: 11
    Well, based on what I just read, you may want to buy everyone Fluffy Bunny slippers. That would solve the cold feet problem.
    Next problem: If you raise your floors in the kitchen and bathroom all cabinetry should be raised as well, to include a new toilet flange, piping, electrical outlets, etc. (I suspect old cast iron soil pipe due to age).
    I have a customer on the West Side of Manchester, NH who's dishwasher went south. I couldn't extract it as there were three layers of floors blocking it's removal. They had countertop people come in to remove that for me so I could perform the job. His wife chose granite as a replacement. Next time the DW decides to croak, it will require two sticks of dynamite and earmuffs, or, cut open the floor underneath. By then, I hope to be retired.
  • hot_rod
    hot_rod Member Posts: 16,326
    If you could give up 3/4" on the floor consider a system like the Roth Panels. They give you some r-value and use pex tube, so any fuel source could be used to heat the water.

    The 1/2 thick Roth panels take 3/8" pex. Float a thin engineered flooring over that for 3/4" total.

    Some pretty impressive engineered flooring for bathrooms now. I've seen samples submerged in water for a week at trade shows!

    The edge loss is your biggest thief, anything you could do to insulate around the perimeter would conserve energy.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream