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Uneven floor problem

lunabean1 | Posted in Construction Techniques on November 23, 2009 07:08am

We are getting ready to put finish flooring in, but we have one section of floor that is very uneven, 7/8″ at the deepest point.   There is closet and doorway where this low section is, so the floor is low all the way across the room, from about 8 inches in front of the closet/wall, to about 2 inches behind the closet (which is the hallway).  Hope that makes sense!

Can a self-leveling underlayment be used here?  The subfloor is 5/8″ plywood, and we’re planning on carpeting.  Also, there is radiant heat stapled up under the subfloor.  Any help would be VERY appreciated!

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  1. FastEddie | Nov 23, 2009 07:38pm | #1

    If the subfloor deflects, the self-levelling copmpund will probably crack, and then you will have chunks of that under the carpet.  Is this new construction, or a remodel?

    "Put your creed in your deed."   Emerson

    "When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it."  T. Roosevelt

    1. lunabean1 | Nov 23, 2009 08:02pm | #3

      It's kinda both.  There are parts of the house (like the joists and subfloor) that are older.  The radiant heat is new.  I know we probably should have fixed the floor before the pex was stapled up, but this was last winter, and we were freezing!

      I've just been reading through some older posts, and there were some suggestions about removing the plywood and shimming underneath.  I don't know if this would work for us because of the walls sitting on top.

      We don't have a contractor right now.  This is a secondary house for us, so we've been hiring subcontractors (like the plumber who put in the boiler and radiant heat) as we get the money to continue.  If the solution doesn't look too involved, my husband will probably tackle this one.

      1. lunabean1 | Nov 23, 2009 09:14pm | #5

        Oops!  Meant to say that the walls are new, too.  It's a new(er) house buillt on an older foundation.  The joists are 2 X 10, spanning about 14 feet.  The closet walls run parallel to the joists.  Above the closet is the loft.

        One more edit - based on some of the other problems we had with the builder, I'd say there's a small amount of bad workmanship, but nothing catastophic.  We're not working with him anymore, but have done our best to stay on a friendly path (very small town).  I can probably get more info from him if needed.

        Edited 11/23/2009 1:16 pm ET by lunabean1

        Edited 11/23/2009 1:18 pm ET by lunabean1

        1. Piffin | Nov 23, 2009 09:21pm | #6

          @14' span on 16" centers, that should be OK.Is this sagging out in the middle or is the whole plane off level or??? I just don't have the problem clear 

           

          Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

          1. lunabean1 | Nov 23, 2009 09:58pm | #7

            This is a 14' X 16' room, with the joists spanning the 14' width.  At one end is an exterior wall.  At the other end of the room, where the doorway is, there is a closet that is parrallel to the joists.  Most of the floor is fine, it's just where the closet and doorway are that's much lower.  The floor starts to dip, all along the width of the room, about 8" in front of the closet.  The low section continues under the closet, and then ends a couple inches behind the closet, which happens to be in the hall.  So the floor is lower on one side of the hallway as well.

            I hope I've managed to clear some of this up.  I'm not all that great with words! 

          2. Piffin | Nov 23, 2009 11:57pm | #8

            You actually do pretty well with words. It is just hard to use words to paint a 3D picture. I think I have it now.It sounds like this may have been an addition?I would want to check under the floor in the crawl space to be sure this end of things is properly supported first and know what the reason is that the floor is low here.It seems more than 50% likely that there is some load transfer from roof that passes to the floor here via the wall at door and closet back, and that there was failure to adequately support that load transfer to foundation. If you simply shim or use a poured floor levelor without fixing any other cause of trouble, it will continue to get worse. If you can get phot5os to post of the attic space ( roof framing) above this wall/closet are, and the crawl space or basement under it, we can batter advise you as to best solution. 

             

            Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

          3. KFC | Nov 24, 2009 12:41am | #9

            I think Piffin is doing a good job of helping you figure this out. But, for my own visualization purposes, can you clarify the size (as viewed from above) of this low area? Is it a depression a foot or two wide and a few feet along the same axis as the wall/closet door at the wall/door? Or is it a general tilt of the entire floor towards the closet area?k

          4. lunabean1 | Nov 24, 2009 03:01am | #10

            A depression is a great way to put it.  In more ways than one :)  This depression is two and a half feet wide and is the width of the room - closet + doorway.  There is a basement underneath and a loft on top.  In the loft is a knee wall that sits pretty much where the closet is, so maybe there is load transfer, though the end of the rafters rests on a pretty hefty beam about six feet beyond where the knee wall is. 

            I can take pictures next time we go out, which will probably be the weekend after next.  Thanks so much for taking the time to help us sort this out!

          5. KFC | Nov 24, 2009 03:12am | #11

            OK, so it's not just a slanting floor. Another piece of the puzzle...
            I'll check back in a while, but Piffin is a smart knowledgable dude, so I'll see what he has to say first.
            k

          6. frost | Nov 24, 2009 04:10am | #12

            I've had a few old homes with similar issues.  I think the advice given so far has been great.  I thought I'd chime about a few instances where I've had to make the same call.

            A few times ,I have laid either 1x6 or 1x8 Spruce/pine flooring (#2) over some very difficult floors where I was told to level it first.  That type of flooring will bend as you need it and can also be sanded with hand sanders in a few hours for a moderate sized room (back be willing).  Cost here has been .80cents to a dollar a bd.ft. which is the same as sq.ft. for this purpose.  Of course, this assumes you put it down, sand it and put 3 coats of finish on it. It is a lot cheaper than carpet, it looks kind of good, and it does better with radiant than does carpet.  Downfall is that it is very soft and will show"character" quickly.  With some appropriate throw rugs and runners though, I think its great, as does anyone who visits.  Floor remains wavy.....You may choose to shim any real bad spots, some use asphalt shingle below or something similar. A few creaks when you walk on a wavy floor makes your friends jealous. Consider wood instead of carpet, just make sure the nails/staples do not penetrate the subfloor and penetrate your radiant tubing.  1 1/2" nails at an angle should be ok, but work it out yourself.

             

            Best of luck

          7. KFC | Nov 24, 2009 06:36am | #15

            I hear you. I have put Doug. Fir flooring down a couple of times, and it conforms easily to most little whoop-de-doos. It also gets "character" (i.e. scratches and gouges) from a sideways glance, not that that ever bothered my aesthetic sensiblity. Carpet will dampen radiant heat somewhat, although how much is debatable.I recently laid bamboo down in a kitchen reno. floor that sloped more than an inch in eight feet, and the client had never noticed the slope in the twenty years she'd been in the house... but that was a relatively even amphitheatre shaped slope towards one wall.In this case, however, it sounds like there's some specific settling going on at the closet wall which may need to be checked out before any flooring is put down.k

          8. lunabean1 | Nov 25, 2009 04:43pm | #16

            We'll have someone come out to take a look at the settling and see what we can do so it doesn't get worse.  I don't think there's much we can do about the load that's on top, but the basement is open, and we can add something underneath.

            On a carpet note, we're using modular carpet squares from Flor.  They're about 1/4" thick and, in our case, will sit right on top of the plywood.  They will insulate a bit with the radiant, but because they don't use padding underneath it's not much worse than wood (according to the info from their company).  Not much cushion, but this is for the kids' room and we wanted them to be able to drive their cars or build with blocks.

            With this dip in the floor, over such a small space and because of the location, you actually trip on it from time to time.  Can the plywood around the walls be removed, shimmed and replaced, or is it better to leave it in one piece and level from the top?  If leveling compound won't work because of cracking, what other material might build up that area?

            Thanks again!

          9. FastEddie | Nov 24, 2009 04:58am | #13

            Two and a half feet is about 3 joists wide.  I wonder if they left out the middle joist, or maybe it is set way low."Put your creed in your deed."   Emerson

            "When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it."  T. Roosevelt

          10. Piffin | Nov 24, 2009 05:46am | #14

            It's possible that a couple joists were set low for some 'reason' known only to the nail banger, but My money bets that somebody made a change at some point that affected structural load carrying capacities and overloaded an area intended to only carry live load and not all that transfer. 

             

            Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

  2. User avater
    lindenboy | Nov 23, 2009 07:56pm | #2

    Seen it used very successfully, both the more heavy duty commercial type (MAXXON) and the bag / mix type.  I would recommend cementitious instead of gypsum based, but for carpet it's probably okay to use the Gypcrete 2K type of mix (or something similar).

    Either use screws set just below the finish height to gauge your thickness across the poured area, or use lath to space up to your finish height.  Pour away!

    "It depends on the situation..."
  3. Piffin | Nov 23, 2009 09:04pm | #4

    A lot depends on WHY it is off.

    Not sure that I understand the details without a road map.

    is this an old house? Underframed? bad workmanship?

     

     

    Welcome to the
    Taunton University of
    Knowledge FHB Campus at Breaktime.
     where ...
    Excellence is its own reward!

  4. lunabean1 | Jan 18, 2010 02:20pm | #17

    It turns out one of the joists under the low area had been notched out - who knows why? On top of that, there should have been more support, since the closet wall is carrying part of the load from the knee-wall and roof in the loft above. What really gets me is that not only did we not notice it, but no one else said anything. Not the electrician (who installed a light along the notched joist), not the plumber (who put the radiant heat in alongside the notched joist), and not the handyman (who put the insulation against the notched joist)!

    I sistered in a joist along the notched one, then we put two 2 X 12s under the entire area. According to a local builder, that should stabilize the floor so it doesn't get any worse.

    Here's what I did to fill in the low spot. I used luan and 1/8" vinyl tiles, layering them as needed, then filled in the ridges that were left with some silicone caulking. It looked kind of funny, but with the carpet squares over the top, you can't tell the floor used to be uneven.

    I can just see some homeowner down the road taking up the carpet and going, "What the...!"

    File format

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