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Questions: over old adhesive / elevation

carol_lynn
carol_lynn Member Posts: 6
edited May 23 in Radiant Heating
I’d like to install electric heat over a current slab. It has a little adhesive I’m having trouble removing (black/hard/there from over 30 years ago). 

I’d like to have minimal added elevation. The floor adjoins two other spaces. The current concrete is even with the surrounding wood floor. 

Can I attach the heating coils directly to the current slab then add a very thin concrete over the coils? 

Also can I have no coils about 12 inches into the room where it meets the surrounding wood floor for a gradual slope to meet the needed elevation for the coils to be covered? I’d like the change in elevation to be noticeable as little as possible. 


Comments

  • Preiss
    Preiss Member Posts: 14
    What was on the floor prior. Looks more like floor level than adhesive to me.
  • Preiss
    Preiss Member Posts: 14
    My flooring guys use 3 foot razor scrapers. They get on their knees and go to town. Some serious elbow grease. Are you planning on keeping the floor a concrete lock. You don’t have a lot of room for build up based on the height of your door thresholds.
  • mattmia2
    mattmia2 Member Posts: 3,598
    I guess the better question is, what is your goal here? Electric radiant will only be able to make the floor warm, it won't be able to make up for the heat loss of all that glass. If you want to make your feet warm when you walk around barefoot then this could be a good option. If you want to actually heat the space, some form of appropriately sized electric or hydronic radiant panel or panel radiator on the wall or ceiling would be more effective.
  • STEVEusaPA
    STEVEusaPA Member Posts: 5,177
    You have a moisture/mold problem you should address first.
    By electric heat, do you mean the mats with electric elements? At best you'd only get floor warming, and it would most likely be way too expensive to run to actually heat the room.
    steve
    mattmia2carol_lynn
  • carol_lynn
    carol_lynn Member Posts: 6
    Thank you for your input.

    I would like to make it warmer so I thought adding some type of floor heat would help and I should decide that before deciding on what to do with the floor. Originally I was just going to paint it. Then I thought floor heat would make it more comfortable. I’m in Michigan. 

    It’s in between my dinning area butts up to the living room and has a bedroom on the other, right side, wall. 

    How do you see I have a mold problem? That left corner? I ripped out a cabinet that was there and that wall is coming out. 

    I don’t know anything about wall or ceiling heat. Can you offer some info on heating that space? My house is only 1500 square feet, crawl space and no attic-flat roof except part of the living room. 

  • psb75
    psb75 Member Posts: 433
    It's most likely that there is no insulation under the concrete. Therefore, most of the heat energy will be used to attempt to warm the concrete and very little heat to the room.
    The mold problem appears in the left corner and under the adjoining door and window jamb. Also the water staining on the concrete in that area. Moisture and electric heat mat is not a great pairing.
    carol_lynn
  • mattmia2
    mattmia2 Member Posts: 3,598
    It looks like those french doors and windows are leaking or maybe the joint with the patio or both.

    How is the rest of the house heated?
    carol_lynn
  • carol_lynn
    carol_lynn Member Posts: 6
    edited May 26
    The rest of the house is heated with furnace heat. I have propane. I have a fireplace - wood burning. 

    I did pull up some of the caulk by those doors to redo it, but I’m but sure it wasn’t also leaking some before that. Would new caulk solve a leak there? 

    Here’s a pic; the stuff is temporarily there because of the work I’m doing. 
  • carol_lynn
    carol_lynn Member Posts: 6
    edited May 27
    Would putting a wood burning stove insert inside the fireplace be a good way to get more heat in that entire area? And for a cheaper cost to run? 

    Caulking the French doors at the base and exterior? 

    And then sealing the concrete with primer moisture sealer and then painting over the primer. Then putting down a large throw rug. 

    Regarding panels, I’m thinking that might also be more costly to run-is that true?  I’m looking at ceiling options for those. Do you have a company you prefer? 

    Whatever other ideas you have would be great appreciated. 


  • Preiss
    Preiss Member Posts: 14
    I agree it looks like you have or at least did have moisture issues. The wall left of the doors appears to have mold, some of the door sills and the second from left door bottom seems to have some mould, rot or swelling issues. Make sure all water issues are resolved first. Check your exterior door flashings and caulking as well as your downspouts leading water away from the house. If you do experience intermittent moisture entry or if the slab gets damp on occasion your best bet for the floor would be to Install decorative tiles over a cement based thinset which aren’t affected by moisture and don’t promote mould growth. You’ll also want to use a epoxy based grout. If the tiles adjacent the hardwood floor were bevelled a little to create a minimal threshold taper you would not have a trip hazard and it would look pleasing to the eye. As far as heating I would recommend electric baseboard because it’s easier to run electrical through walls and it looks like you have some wall work to finish. To prep the floor you need to either scrape it or you may be able to rent a device called a Bush Hammer which roughens and prepares the floor for bonding agents like thinset. Hopefully some of these ideas will help you decide how you want to move forward with your project. 
  • JUGHNE
    JUGHNE Member Posts: 8,666
    Did that concrete floor area used to be outside? And did someone bump the wall out to create that room?

    If so and it is just on an uninsulated slab and cold foundation then it is always going to be cold.

    That moisture problem could be humidity in the house condensing on the large cold window wall you have out there.
    A window wall like that should have maybe 3 heat runs in the floor to keep the glass warm and prevent condensation which would run down the glass and land on the bottom of frame.
    When really cold out do you get any oval shaped areas of condensation on the glass?
    If so then you may have some collapsed glass panels, they lose their gas charge and the glass in the center of the double pane unit comes closer together and that area is very cold. I know as I have a Frenchwood Anderson stationary panel that does this. You can tell at night with a ceiling light and observing the reflection of the ceiling fixture, it is distorted and if you move you head back and forth the fixture seems to swing like a bell.

    If these are Anderson windows and you have this issue call them.
    My house wall built in 94 and most of the south window glass collapsed together, at that time they came out and replaced all the windows with no charge.
    Some years later the same thing happened to other windows, they came out and drilled a small hole in the corner of the glass and let air in, sealed the hole (again no charge) and so far I have only the Frenchwood patio stationary glass with the issue.
    I may call about that, but we keep that room at least 72 degrees with radiant floor heat. The frost/sweat happens pretty seldom now.



    The simple solution I can think of is electric heat.
    Cove radiant heaters mount near the ceiling and would provide some comfort.
    You have a large header above the wood/concrete junction and could mount a long radiant heater on that header pointed near the window wall. Also a couple on either wall of the room. It will cost to heat this by any method.
    Radiant heat of this type will heat objects and may keep the glass warm enough to not sweat in the winter time.
    But any floor matt will still cost you for kilowatts and not be as effective.
    carol_lynn
  • mattmia2
    mattmia2 Member Posts: 3,598
    You might be able to heat it with a propane console heater that vents out the sidewall, that probably will be somewhat less expensive to run than the electric heat. The first step would be a heat loss calculation to figure how much heat you need.
    JUGHNEcarol_lynn
  • carol_lynn
    carol_lynn Member Posts: 6
    edited May 29
    Thanks again!  To answer the question of when the slab was put in, it was here when we purchased the house 25 years ago. 

    I’ll show a picture of the whole room; it’s the main living area. 

    Where the large opening is, that use to be old aluminum sliding glass doors. There was an old wood and glass pocket door on the left. The French doors, are Anderson, and we put those in to replace aluminum glass sliding doors. From under the house it doesn’t look like the pad is over the crawl. I’m guessing it was poured when the house was built. 

  • JUGHNE
    JUGHNE Member Posts: 8,666
    Matt's idea for a wall mounted LP heater makes more sense than the electric route I mentioned.
    It must go on an outside wall, it vents thru the wall. The LP line could be buried or run on the outside of the house.
    You can get some that have a glass front for the fireplace look without the wood hassle.
    Some have fans, some will operate without electric power....good for outages.
    Your propane supplier may have more info for these heaters.
    With the open floor plan you could have a fairly large sized heater.

    You do not want an unvented one, not only a CO hazard but will put a lot of humidity into the house, something you do not want.
    carol_lynn
  • carol_lynn
    carol_lynn Member Posts: 6
    Would apoxy on the floor help stop cold from coming through vs paint and sealer? 
  • JUGHNE
    JUGHNE Member Posts: 8,666
    Carpet.....
  • mattmia2
    mattmia2 Member Posts: 3,598
    It is possible that you could get large enough ductwork in the walls on each side of the opening to heat that space but there will be a lot of structure in there, especially the one to the left or you could possibly fur them out. Make sure it is someone that did the math because that area will need a lot of heat with all that glass. Is that clearstory window and cathedral ceiling original or did someone remove the ceiling at some point? I'm thinking whoever did that 80's "modernization" didn't recalculate the heating needs for that part of the house.