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Laying your Wooden Floor

April 6, 2010

Reclaimed Pine Flooring in a bedroom
written by Vicki Bale



All our floors whether reclaimed flooring or new oak flooring can be laid by a carpenter or competent DIY enthusiast. We work closely with a small team of fitters whom we can recommend should you require an expert.

Here are some laying tips:

Laying strip and board floors

  • Laying over a concrete sub-floor
  • Sub-floors must be fully dried out with a maximum moisture content of 5% and must contain an effective damp proof membrane. For a “belt and braces” job lay building paper on the concrete as an additional vapour barrier.
  • Battens should be screwed and countersunk on to the concrete. Centres should measure no more than 300mm.
  • Minimum thickness of battens should be 25mm (20mm is possible if the nailing is driven at 30 degrees).
  • Normal batten width is 44mm.
  • Thermal insulation is improved by laying insulation between battens.
  • Ensure all underfloor pipework is lagged before the floor is laid. This will prevent localised shrinkage in the floor from hot adjacent pipes.
  • Laying on ground floor joists
  • Hardwoods should not be nailed direct to joists over a ventilated ground floor void. Flooring will absorb airborne moisture from the ventilation and will swell.
  • We recommend that plywood of at least 18mm is laid first followed by a sheet vapour barrier (not polythene) and then the hardwood floor.
  • Laying over an existing floor
  • You can lay over an existing floor if it is sound and level.
  • Counter punch any nails and check the floor for high spots before sanding flat if necessary.
  • Lay your new floor at 90 degrees to the existing floor if possible and nail at 300mm intervals.
  • If your new floor must run the same way as the old one, lay plywood of at least 6mm thickness to the old floor before laying the new one. It may save cost if the plywood is laid in strips at 300mm centres. In both cases when you lay the new floor fix with nails of sufficient length to fix through the ply and into the old floor.
  • If your existing floor is laid over a ventilated void ensure that a vapour barrier (not polythene) is sandwiched between the old and new floors.
  • Other laying tips
  • Wide boards are more likely to bow than narrow ones especially if laid in rooms subject to seasonal variations in temperature and humidity. If you are secret nailing t&g wider boards (ie where the width of the board is >5 times the thickness of the board) consider additional fixing by nailing through the face of the plank, plugging the hole with a plug made from the timber. This will give a smooth finish if you do not wish to see the nails.
  • It is a wise precaution to treat all battens and existing timber joists against infestation and rot before laying your new floor. Although we never knowingly sell infested timber you may also wish to treat our flooring.
  • Remember all timber moves between seasonal extremes, expands in summer and shrinks in winter when the heating is on. This is quite normal.
  • T&G end matched boards need not terminate on a joist or batten provided the board on either side does not terminate between the same joist or batten.
  • Always leave an expansion gap of round the perimeter of the room. This should be 15mm for small rooms and 15-20mm for larger rooms. In most cases the gap will be covered by the skirting board.
  • Cramp boards before fixing to ensure a tight fit.
  • Nailing
  • When surface nailing use a nail punch to drive below the floor surface. This will assist sanding.
  • T&G floors may be secret nailed using a porta-nailer and driving the nails in at 45 degrees. Use 45mm nails or staples for a typical 20mm thick board.
  • Traditional floorboard nails, cut nails (brads) are best for surface nailing use 65mm brads for boards up to 25mm thick.
  • Laying parquet
  • Reclaimed blocks need cleaning, not on the underside but on the ends and the sides. The bitumen on the bottom, provided it isn’t lumpy can be put straight into the special adhesive.
  • There are several different ways of laying parquet, the most popular being the herringbone pattern.
  • All the same rules on ensuring the dryness of the concrete sub-floors apply. A paint on damp sealer is a recommended extra precaution.
  • We recommend and sell Lecol 5500 adhesive for use with reclaimed parquet blocks. From experience it provides an excellent bond.
  • Notes
  • Please view the sections on Background & Preparation and Finishing and Maintaining flooring.
  • We are suppliers and not fitters of wooden floors, so we are unable to quote for a fitted price.
  • If you follow advice given on any of our pages, it is entirely at your own risk as we have no knowledge of site conditions.

Thanks to Pete Mountford and Melvyn Dunk for their assistance in writing this article.

We cleared all our reclaimed flooring in 2012 and we now concentrate on door furniturewindow furniture and bathroom accessories. All traditional in style and best quality. Click here to go to our home page.

Leave a comment


    I am replacing the wood floors in my 1920 home. Right now, I have 3/4 TG hardwood, which is not in the best shape, over a 2.5″ wide x 3/4″ inch think plank subfloor, which runs perpendicular to the joists (2×10, 16 oc).

    Ideally, I would tear out the existing finish flooring, screw down the existing plank subfloor where loose, repair the plank subfloor where needed and then lay my new flooring (engineered hardwood) right over the existing plank subfloor. However, the conventional wisdom seems to be that you should install a layer of plywood, at least 1/2 but ideally 5/8, on the existing plank subfloor before installing the new finish floor.

    My question is why? If the existing plank subfloor is in great shape, what am I getting with the additional layer of plywood that I don’t already have? I’m sure there is a reason why most people recommend adding plywood on top of plank subfloor. I’m just trying to understand.


    Vicki Bale says:

    Hello Joseph
    I am sorry but we have not been in the flooring business for over three years. We are not qualified to answer your question and I suggest you consult a carpenter or qualified floor fitter.

    Rob Rainbow says:

    Very helpful. Thank you. I intend to fix an oak floor on an old pine one. There is a ventilated void beneath. Could you let me know of suitable vapour barriers to fit between to old and new flooring, please?

    Vicki Bale says:

    Hello Rob. Thank you for your question. I am sorry but we have not sold flooring for some years and I am not qualified to provide an answer.

    I think it’s important to highlight the significance of leaving an expansion gap – any real wood flooring expands and contracts throughout different times of the year as it absorbs and loses moisture. Failure to leave a suffienct gap can result in the floor raising, buckling and ultimately ruining the floor entirely.

    Great post by the way!