Fitting Hardwood Floors Over Solid Subfloors

If you've been charmed by the appeal of wood flooring but have discovered your subfloor to be concrete, tiles or asphalt, don't be dismayed by this as you can still lay beautiful hardwood floors on top.

Classic Oak Hardwood Flooring Classic Oak Hardwood Flooring

Before going into the fitting options over your solid subfloor, we always recommend that you need to firstly consider the relative humidity of the air in the room where the floor is to be installed - ideally this should be 50-65%. You can find more information under the 'Preparation' section (page 4) in our Hardwood Floor Fitting & Maintenance Guide.

Floor Fitting Options

There are 3 ways of fitting wood flooring onto solid subfloors:

  1. Glueing (not applicable to asphalt)
    • Ensure that the solid subfloor is fully dry. If concrete, screed or render has recently been laid; we advise a minimum drying time will take 1" per month. So if you have laid concrete that’s 6" thick, you will need to wait at least 6 months before fitting your hardwood floor. We cannot stress the drying time enough, as we've seen floors pop and buckle.
    • If you’re satisfied that your solid subfloor is dry, apply a continuous damp proof membrane (DPM), such as Taylor EnCap 500 Concrete Barrier & Adhesive Encapsulator.
    • Proceed with applying your glue, we recommend Taylor Timberline MS+ Advance Adhesive, as it has a high bond strength but remains permanently flexible. This glue will allows the flooring to move as the seasons change but it will not crack and the floor will stay adhered to the subfloor.
  2. Floating
    Floating a floor means that it is not fastened down to the subfloor below, giving you the advantage of gaining access to your subfloor if required.

    • Lay a full layer of visqueen over the whole subfloor. This is a 300mu (1200 gauge) polythene damp proof membrane.
    • Apply floor fitting foam underlay, which has a strong adhesive coating on one side with a peelable protective film. A very popular method of fitting as it vastly reduces installation time compared to traditional mechanical fixing and glueing techniques.
  3. Mechanical Fixing (with additional subfloor)
    A more traditional way of fitting hardwood flooring, through the methods of nailing or screwing the floor down. The advantages of mechanical fixing is that you have extra damp proofing, added height and the ability to lift floor boards up if access to subfloor is required.

    • Lay a full layer of visqueen over the whole subfloor. This is a 300mu (1200 gauge) damp proof membrane.
    • Lay down your additional subfloor, i.e., chipboard, plywood, OSB board or battens.
    • Pin a layer of building paper over the subfloor (chipboard, plywood, OSB board or battens). This is a belt and braces approach to further damp proof and protect your hardwood flooring.
    • Now that your subfloor is prepared, you can either face nail, secret nail or secret screw your floor boards down.
      Secret Nailing Hardwood Flooring Secret Nailing

For more information, download our Hardwood Floor Fitting & Maintenance Guide. You will find techniques and tips to the various fixing methods mentioned along with preparing and maintaining your floors.

If you have any questions, feel free to comment on this blog, call or email us. We know fitting hardwood flooring can be a daunting task, especially if you're going to tackle the project as a DIY. So we're always on hand to give you the best possible advice to make sure your installation project goes smoothly and that you enjoy the feeling that hardwood flooring brings to your home or office.

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