Hardwood over concrete?

Discussion in 'Remodel Forum & Blog' started by Erico, Jan 17, 2011.

  1. Erico

    Erico New Member

    Messages:
    73
    Location:
    NY
    I'm remodeling my kitchen - including replacing the whole room full of ceramic tile with maple flooring (new ceramic tile will go tile near the sink/dish washer).

    This is a third floor condo in a 100 year old Chicago building.

    I was expecting to find plywood under the ceramic seeing as though this floor was done in the late 80s or thereabouts (I didn't own it then) and that seemed to be the "cheap way" to do it back then. For instance, the bathroom had plywood under ceramic. It came up rather easily with a chipping gun.

    Much to my surprise upon removing cabinets, there is a layer of concrete under the tile in the kitchen.

    I haven't gotten in to demo'ing the entire floor yet so I'm not sure if this was only poured in a low part of the kitchen or the entire floor. It seems to be at least an inch thick based on the portions I can see under the cabinets and in to the adjoining laundry room.

    I'm assuming a couple scenarios where this concrete would have been used.

    1.) as a leveler in only the low spots.

    2.) a leveler under the entire kitchen

    Either way, wood is going to have to be place over at least a partial concrete floor.

    It looks like the 3/4 hardwood I wanted is out and I will have to do an engineered product. Height wasn't an issue as the kitchen floor was about an inch below the dining room hardwood. My plan was to screw/glue a new clean layer of 1/4 plywood down and then 3/4 hard wood.

    I guess my main question is what moisture issues do I have to deal with with above grade concrete - and can I glue engineered flooring directly to above grade concrete or will it need a vapor barrier. I'm really trying to avoid a "floating" floor.

    Also, there may be a height issue where I may need to place a layer of at least 3/8th or 1/2 inch plywood down. Can I glue and tap-con that? And then nail/glue engineered? 3/4 hardwood would be out at that point due to height issues.

    Obviously the manufacturers recommendations will be followed for whatever floor product I chose but I need a little lesson in hardwood/engineered wood over ABOVE grade concrete.
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,018
    Location:
    New England
    There shouldn't be a moisture problem with above-grade concrete. Are you sure it is concrete and not soft like a gypsum product? In either case, you don't really want to put fasteners through it.

    A floating engineered wooden floor of any size, really doesn't move. I have it in my first floor, and the weight of the stuff is just so much, along with the friction to the underlayment, that it is solid. Like any wooden floor, you do need to leave an expansion joint around the edges. I was really impressed the the stuff from Kahrs - the only thing they make is wooden flooring, and have been doing it since the 1850's. Many of the engineered stuff can be glued down, or floated. Read the specs carefully. Repair or replacement is much easier if it is floated.
  3. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    You would be crazy to use anything other than engineered hardwood in a kitchen anyways...
  4. Spaceman Spiff

    Spaceman Spiff Architect

    Messages:
    277
    Location:
    Salt Lake City, Utah
    My parents have had 3/4" solid oak in their bathroom and kitchen for over 20 years now and have had no problems. If properly finished water is not a concern.
  5. Erico

    Erico New Member

    Messages:
    73
    Location:
    NY
    I don't know that I agree with that statement. I have another condo unit with a 100 year old maple floor in the kitchen and it looks fine. In fact, the whole building has maple kitchens. There is even evidence of old maple kitchens in the front of the building (we think the units were split up at one point - maybe in The Great Depresion).

    That's how they used to do it and it worked just fine. Because Maple is a dense wood, it does stand up to water a bit better.

    Today's finish process on pre-finished product is much better - or so I hear.

    I would rather use a 3/4 product that can be re-finished if need be.
  6. Ian Gills

    Ian Gills Senior Robin Hood Guy

    Messages:
    2,777
    Location:
    USA
    Don't cheap out and use ceramic tile.

    Use porcelain tile instead.
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,642
    Location:
    Cave Creek, Arizona
    That is how they installed ceramic tile in the "old days". The wood floor was depressed and a layer of concrete, usually 2" thick, was poured on top of it, and then the tile was cemented to it. IT had nothing to do with "leveling the floor". They just felt that ceramic tile needed a concrete base for a proper installation.
  8. Erico

    Erico New Member

    Messages:
    73
    Location:
    NY
    I agree that was the right way to do it. I'm just surprised it was done the right way. I expected plywood - that's how the bathroom was done. And the rest of the pace is pretty tacky:

    Drywall over old plaster over lath.
    A window drywalled over a bricked-in window with NO insulation
    A buried copper drain sink drain stub-out with what appears to be a spray-can lid used to seal it.
    Cast iron joined to copper vent with fernco completely detached (I can't believe there is no sewer gas smell)
    The sink was, at one time, apparently moved over a couple feet. Rather than move the drains they put a 90 elbo in and notched the back of the cabinets.
    The bow in the cieling was drywall nails pulling loose from weight of plaster they covered over nailed up - no screws.

    I'm used to it though. This isn't te first vintage place I've owned. I'm used to wavy-gravy cieiling corners and the bowed walls from the plaster and lath being drywalled over with no sense or care of what is straight.

    I'm getting the feeling the floor was so out of whack they HAD to do it the right way (It looks to vary between 1/2 inch and a little over an inch). Or they found a tiler who cared about his trade.

    Either way, it's a moot point. It looks like the concrete layer HAS to come up. The middle section held up but the edges of the concrete came up with the tiles. I suppose I could try to patch it and even go over everything with some self leveler but that could be a lot of work and still have a crunchy floor.

    I think it's going to be sleepers and plywood.
    Last edited: Jan 20, 2011
  9. Erico

    Erico New Member

    Messages:
    73
    Location:
    NY
    Agreed. I just used ceramic as a generic term. I'm partial to stone but there are some awsome porcelains out there too. Porcellain makes more sense for deflection reasons.

    I may just go hardwood all around for deflection reasons.
  10. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,018
    Location:
    New England
    While porcelain may be stronger, it counts for nothing in the long-term survival for deflection issues (it's still brittle and will crack with deflection)! BTW, porcelain IS ceramic, just a different kind (like gouda and swiss are both cheeses, but different). To support natural stone, because it isn't as homogenous and likley has some internal flaws, the industry standard calls for the floor to be at least twice as strong as that for ceramic. There is a big variation in quality of both typical ceramic and porcelain tiles. If the porcelain is glazed, then the surface could be softer and more subject to scratching than a good glazed plain soft ceramic tile. Impact from dropping things on it would still likely be better for porcelain. There is an industry standard for a glazed tile for wear (PEI test rating), and it is the same test for any glazed tile, regardless of what it is made of. That test isn't generally run on an unglazed, porcelain tile, though. A PEI rating of 5 is industrial...a typical home would likely be okay with a 3-4, depending on where it is planned to be used. A bathroom, far away from an entranceway where it is not often subject to sand and grit, might get by with a lower rating. One right near an entrance, might call for a higher rating to look good longer. Porcelain is made from a finer grained clay, compressed during forming the tile, and fired at a higher temperature than typical ceramic tile so it ends up denser. But, some ceramic tiles are made the same way, but with less expensive clay, and come out nearly as hard and strong...it all depends.
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