Announcement

Collapse
No announcement yet.

Plywood Subfloor levelling prior to nail/staple hardwood floor

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Plywood Subfloor levelling prior to nail/staple hardwood floor

    I'm deeply lost.

    I'm asking around, and seem to have every single solution and it's contrary. I'm trying to find the right way to do it, so we can move on with the project and prepare the rooms prior to our baby coming in a few months. So, here's the general status.

    We had parquet floors in three rooms that dates from the construction of the house, about 30 years ago. Unfortunately, the glue used to put the floor down was stronger than the glue in the plywood subfloor. So, even with care and meticulous removing of the old floor, some plywood delaminated, creating some low spots here and there. These low spots vary, but are usually between 1/8" up to 3/16".

    We're installing a maple hardwood floor on top that will be stapled or nailed down. The floor board will be 3/4" thick, 4 1/4" wide, and roughly 4-6' long. If I install the floor board perpendicular to the beams under the plywood, the floor boards will be parallel the low spots.

    What should I do?

    1- Don't do anything and install on top.

    2- Use a floor levelling compound, even though it might crack or break if nails go through, using it only in the low spots rather than the whole surface.

    3- Use a magic floor levelling compound that can be nailed. (If so, what brand and product should I use ?)

    4- Use another kind of shims.

    5- Super brilliant technique I haven't heard about yet and will resolve all my questioning.


    Thank you in advance for your help and wisdom.
    Attached Files
  • Thread Continues Below...

  • #2

    Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

    Caveat .... not an expert, but I did run into the same thing in a kitchen 15 years ago with tile, not parquet and not quite as bad.

    What I did was lay down 1/4" Poplar flooring underlay and screwed it every 6" without drawing the screw heads deeply into the ply (just below flush). Then I installed my flooring. There were a couple of really bad spots, so I applied some auto body filler in those as a rough leveller/filler before laying down the ply.

    cheers

    Comment


    • #3

      Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

      Maple at 3/4" thick and 4.25" wide with tongue and groove will never "fall" into those low spots even if you bring a herd of cattle into your room. Go with number 1 in your options.

      Comment


      • #4

        Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

        I'd agree with what 'RV Sam' says.
        That was a well-built home if the flooring was glued down that much.
        Thanks

        Moe Fretz

        Comment


        • #5

          Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

          Originally posted by RV Sam View Post
          Maple at 3/4" thick and 4.25" wide with tongue and groove will never "fall" into those low spots even if you bring a herd of cattle into your room. Go with number 1 in your options.
          It’s fine don’t worrry about it.

          Nathan

          Comment


          • #6

            Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

            I don't really disagree with the "don't do anything" people but if you don't like the result you'll have a problem after the flooring is installed. I doubt if it will fall but I'd be concerned about hollow sounds when the floor is walked on in the larger unsupported areas. I'd get something like heavy paper/cardboard/vinyl sheet flooring and staple (layers of) it into the bigger areas first. Doesn't have to be neat and elegant.
            billh

            Comment

            • Thread Continues Below...

            • #7

              Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

              Originally posted by billh View Post
              I don't really disagree with the "don't do anything" people but if you don't like the result you'll have a problem after the flooring is installed. I doubt if it will fall but I'd be concerned about hollow sounds when the floor is walked on in the larger unsupported areas. I'd get something like heavy paper/cardboard/vinyl sheet flooring and staple (layers of) it into the bigger areas first. Doesn't have to be neat and elegant.
              billh
              A squirt of construction adhesive under any hollow area would bond the wood to subfloor.

              Nathan

              Comment


              • #8

                Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

                It’s hard to tell how uneven the floor really is. Even with wax paper, you’ll probably get the odd squeak. If you have a few deep divots, you can fill them with anything—drywall compound is fine. I’d be reluctant to warranty an installation over that, but I’d probably roll the dice if it’s my house.
                Tim

                Comment


                • #9

                  Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

                  If it was very large layers of laminations that peeled off during the removal process, (not just little chunks and slivers) you could go with 1/4” underlayment or a leveling compound, otherwise, just install the hardwood over 15# felt.

                  Comment


                  • #10

                    Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

                    As Mr Ross often states, the advice you get on the internet is worth what you pay for it. Not to diminish the comments offered but it is your floor, no one else’s.
                    In the early 2000’s we thought oak hardwood was thing to do. We contracted the job to a pro. The 30 year old subfloor, 1 x 4 had shrunk considerably. Enough of a gap (3/16”) to negate any structural strength provided by the tongue and groove. “No need to put down a new sub over the old 1 x 4 as this 3/4” will not flex.” A year later, in the master bedroom, squeaks at the closet and en-suite entrances. I called him on it, he came out and tried running a few drywall screws from underneath but it didn’t help. “It happens sometimes”.

                    in the fall of 2018 we decided to replace the old vinyl in our kitchen and dining area. I felt a new floor should have a new sub as the old vinyl had hardened over time and had a very aggressive mosaic pattern. This would cost me an extra $1,000.00.
                    Not necessary said the estimator and the installer. Within 4 months, the old pattern was clearly visible through the new surface. After some negotiation, the company agreed to replace the floor, including completely removing the new tile and everything below to the original subfloor. I willing paid for the new subfloor. And we got the pleasure of moving our kitchen into the living room and cleaning the entire house twice.
                    A bit different, but why would you not do everything possible to ensure a long life from this new floor? At least clean out as much as you can and cover the area with that dark grey self levelling compound.
                    Contact any flooring contractor and ask them if they would warrant their install on your current surface? Review the installation guidelines of any hardwood flooring manufacturer. They know.
                    If I had done my floor the way the it was done, I would have doubled the cost, which becomes more significant once your retired, and the personal cost of having to explain your money saving idea to the person you share morning coffee.
                    Certainly everyone has a different experience. Mine says your floor is one place not to take shortcuts for any reason.

                    Don

                    Comment


                    • #11

                      Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

                      I am a trim carpenter.
                      I install a lot of hardwood floors.
                      I would install over that and not worry about it.
                      Use adhesive if you end up with a joint over a hollow spot.

                      If the hollows are deep then add a layer of 3/16 laun underlay.
                      Screws every 4 to 6 inches.

                      Then your hardwood.

                      Don't waste your time with shims/ self leveler etc

                      In all honesty, you are using 4 1/4" wide maple planks. It will be fine.

                      Nathan

                      Comment

                      • Thread Continues Below...

                      • #12

                        Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

                        I have installed a house full of 3/4 inch flooring. As nnieman says it will span the minor imperfections with no problem. If you have large low spots these should be dealt with by using a thin ply as underlay to prevent flexing and squeaking.

                        Comment


                        • #13

                          Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

                          I've had success fixing spots like that with drywall mud. Not sure how well it actually works, just used it cause I had it and I'm cheap. 2 years and no issues (for me).

                          I'd be mostly worried about any high spots from the rough wood. 1 high spot makes the whole floor a low spot. Good luck.

                          Comment


                          • #14

                            Re: Plywood Subfloor levelling prior to nail/staple hardwood floor

                            I replaced all the hardwood in my house about 4 yrs ago. I ripped out the old strip floors down to the plank subfloor which had shrunk to the point of the tongues no longer were in the grooves.
                            I laid down 1/4” subfloor underlayment with adhesive and paid special attention to screwing that down into the joists below.
                            You could feel the difference immediately after the underlayment was put down and the result was a strong squeak free floor which was even quieter from below.
                            You will never go wrong when you add more structure.


                            Sent from my iPhone using Tapatalk

                            Comment

                            Working...
                            X