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Discussion Forum

Hardwood Floor Expansion Gaps

JasonQ | Posted in General Discussion on March 5, 2007 02:29am

Here’s the scene –

New construction.  Subfloors are 3/4″ Structurwood Gold over 14″ I-joists 16″ OC.  Subfloor is glued, nailed w/ 8d ring-shanks, and screwed down. 

Flooring is 5″ #1 Common red oak. 

Show up at the house today, and the person laying the floor has started already in the informal dining area (about 12′ x 10′ – laying along the short axis).  Everything looks okay, until I see the expansion gap.

Or rather, the lack of one.  He pretty much butted the flooring right up against the bottom of the wall.   Probably has about 6 rows laid. 

I asked, “Hey, aren’t you supposed to leave at least a quarter or half-inch on that?”  His response was along the lines of “No, you don’t really need to do that – it’ll be okay.”

Needless to say, I’m not convinced he’s right.  March in eastern Nebraska is a very dry time, and the flooring is right now as dry (and narrow) as it’s gonna get.     I’m figuring if we continue this way, come summer I’ll have major buckling in my breakfast area, especially in light of the individual planks’ width.

Actually summer doesn’t concern me as much, since the AC will be on.  But during spring and fall, there are often some pretty humid days here, and the AC probably won’t be on those days.

Am I right, or just paranoid?  If I AM right, what can be done to remedy this?  Rip it all out and start over?   Just the offending row?  Rip 3/4 off it somehow (how would I do that anyway??)  I told him to stop laying it until he hears otherwise from me, pending your answers and some other research.

Thanks for your advice…

Jason

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Replies

  1. plumbbill | Mar 05, 2007 03:31am | #1

    Well I have never seen a hardwood floor "peak" cause it ran out of expansion room, but I have never seen one put in with the expansion room around the edges either :-)

    I have seen engineered floors peak & buckle cause someone put them in too tight.

    “When politicians and journalists declare that the science of global warming is settled, they show a regrettable ignorance about how science works.” Nigel Calder,  editor of New Scientist

  2. Ray | Mar 05, 2007 05:07am | #2

    I just finished a new floor in the bedroom of a 100 yr. old house.  Many years ago (probably 50), a new floor was laid on top of the old one - tight against the baseboards.  When we pulled the old floor (and baseboards), we found the wall had been pushed out about 1-1/2 inches.  Had a heck of a time cutting long, tapered pieces of flooring to fit and leave a 1/2 inch gap at the edge.  The wall was built on top of the floor so I didn't have to patch "daylight".

  3. paulc127 | Mar 05, 2007 05:16am | #3

    With standard hardwood flooring I would be concerned enough to ask for an additional guarantee in case it peaks or cups. I'm not familiar with Structurwood Gold, but I think you'll be okay. I copied the information below from Weyerhaeuser's site. Glueing interior walls to the flooring is new to me but it would seem to imply that the product is more dimensionally stable.

    http://www.weyerhaeuser.com/ourbusinesses/buildingproducts/structurwood/installation/flooring.asp

    Quick Reference Guide:

    * Ensure proper design and construction
    * Select thickness and span for desired performance
    * Follow proper storage and handling guidelines
    * Allow for proper ventilation in the crawl space and basement
    * Install strength axis perpendicular to joist
    * Install panel with grade stamp on the bottom
    * Glue joints and joists
    * Space panel 1/8” on 4’ ends
    * Do not force tongue-and-groove – panels are self-spacing
    * Use proper fasteners and follow the approved fastening schedule
    * For improved performance, glue interior walls to floor
    * Minimize exposure to moisture
    * Properly clean up prior to installing finished flooring

    1. JasonQ | Mar 05, 2007 06:02am | #5

      I guess I'm a little confused here...are you saying that because the subfloors are more stable than some that I shouldn't have problems with my finish floor expanding too much?  I thought the finish floors expanded & contracted independently of the subflooring.

      Jason

      1. paulc127 | Mar 05, 2007 08:18am | #8

        I'm sorry, I mis-read and therefore misunderstood the original post. You are absolutely correct the oak floor will expand & contract seasonally. The floor should should have a minimun 1/4 to 1/2 expansion gap on all sides. I think the suggestion to have an expansion joint cut in with crain saw is an excellent idea. in the absence of this I believe you will certainly see the effects any movement. insist on a guarantee in the event of any cupping/peaking.Finally, how long was the flooring allowed to acclimate before installation and what material was used for the vapor barrier?sorry for the careless reading of your earlier question.

        1. JasonQ | Mar 05, 2007 08:40am | #9

          Okay, your reply and the others have confirmed my concerns.  Now I just gotta figure out where to rent a Crain saw, or a worm-drive with a reeeally small gap between the outer plate edge and blade.  Or I just gotta tear the 1st row out and start over.

          If I can't finagle the jamb saw, I wonder if I could work something up with an angle grinder...

          To answer your other questions, the VB is 15-lb felt.  The flooring had been in the garage (closed up, doors and all) since before Christmas.   A few weeks ago, we moved it to the (heated) basement so the drywallers could work. 

          In both cases, it was up off the floor, and a plastic barrier was between the pallet and concrete.  I'd be surprised if the relative humidity has exceeded 30% on more than a couple occasions since then, so I'm pretty sure it's good and dry.

          Jason

          1. Karl | Mar 05, 2007 09:30am | #10

            jason, about fifteen years ago I worked with a framer who had a blade he would put on his skil 77 worm drive that allowed flush cuts. It had a hub with a spacer that set the blade outside the shoe or table of the saw. It was plenty dangerous as it had no effective guard but it would be perfect for your situation.Now all you need is for someone to chime in and tell us what the blade is called or who sells them.Karl

          2. Karl | Mar 05, 2007 09:51am | #11

            I spent the last ten minutes googling for a flush cut blade for a circular saw to no avail. I did run across a recomendation to use a biscuit cutter in a situation such as yours to be able to make a cut 1/2" or so away from the wall to create an expansion joint.I think I would try this before pulling up the first board, ripping a new narrower one and trying to reinstall it tight to the remaining boards.Karl

          3. FastEddie | Mar 05, 2007 04:01pm | #14

            Why do you have to rent a saw to correct the problem?  The wood was not installed properly, tell the installed that he doesn't get paid until it's corrected, at no cost to you.  You said that he is still doiung the work, so there shouldn't be a problem.

            FYI, tar paper is a moisture barrier, not a vapor barrier.

             "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

  4. vinniegoombatz | Mar 05, 2007 05:36am | #4

     

    you are not paranoid, you are getting boned     do not rip it up, cut in a half inch or three quarter inch expansion joint and make sure this is maintained on the rest of the job w strips of half inch ply or pieces of the floor stock turne d on edge    circular saw is too gig     small trim saw might work    a Crain toe kick saw will do it, but have good control as u use it as the small blade creates a lot of torque     or, you could rip cut and demo out the strater course, rip boards of correct width, fit in and face nail again                 hide the perimeter expansion joint w the baseboard and a three quarter inch oak quarter round trim in front of it

     

     

  5. FastEddie | Mar 05, 2007 07:20am | #6

    If he is convinced he's right, have him produce a copy of the flooring manufacturers installation instructions.  I would have a gap all around, especially parallel to the strips.

    "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

  6. Thaumaturge | Mar 05, 2007 07:24am | #7

    Jason,

    All wood expands and contracts period.  If the long edge is the edge butting the wall, the installer is an idiot (IMHO).  If the ends of the boards are butting up against the wall, the installer is somewhat less an idiot, but still careless.  (the boards will expand far more across their 'widths'.)

    The type of subfloor is not relevant to the expansion rate of the oak.  It will do its own thing regardless of fasteners.

    Cut the expansion joint as suggested or be sorry later.

  7. BUIC | Mar 05, 2007 10:56am | #12

      If the flooring is tight to the wall, cut the drywall off just above the top of the floor and remove the cutoff.

      Now the floor can expand and go under the sheetrock.

      Much easier then cutting the flooring...buic



    Edited 3/5/2007 2:57 am ET by BUIC

  8. cobbleboy | Mar 05, 2007 12:29pm | #13

    Ditto BUIC easiest way if the flooring is already installed.

  9. factotam | Mar 05, 2007 04:39pm | #15

    "Am I right, or just paranoid?"

    you are right, all wood products expand and contract

    i have seen solid wood floors buckle from the lack of room to expand and contract

    i have also seen plywood underlayment do the same

    it is not worth taking a risk

     

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