Solid Flooring Installation Methods

Installing wood flooring, for the most part, is actually quite simple. Before learning how to lay solid wood flooring, there is some very important preparation. Ensure that you follow our guide and you will have a hassle-free wooden floor.

Essential Items

  • Hand Saw
  • Pencil
  • Measuring tape
  • Wood to concrete Glue (For Concrete Sub-Floors)
  • Flooring Nailer (For Timber Sub-floors)

Recommended Items

  • Knee Pads
  • Moisture Meter
  • Spacers
  • Pull Bar
  • Electric Chop Saw (to replace the hand saw)
  • Jig-saw
  • 2m Long Spirit Level

Site Conditions Before Installing Solid Wood Flooring

You may have heard the horror stories about wood flooring which has risen up in people's homes or about large gaps opening up after solid wood flooring installation. It is very important to be aware that all of these problems can be easily avoided and one of the most important ways to avoid a disaster is to check your site conditions are suitable before acclimatising your solid wood flooring. We have written an article on how humidity and moisture affect wood flooring. There are a number of essential tests that must be carried out within the room of installation. Passing these important tests will ensure that it is safe to acclimate your flooring. If any of these tests fail, the cause must be investigated and resolved before delivering the floor to site.

  • The Air humidity should be 45-65%. You can test this using a hygrometer.
  • Timber **sub-floors** should be tested for moisture and have a MC% (Moisture content) of no more than 12%
  • Concrete sub-floors should be tested for moisture and have a MC% (Moisture content) of no more than 12% on a prong test or below 3% on a concrete moisture meter. NB Some meters have varying scales so it is vital to check their documentation.
  • Check the sub-floor is level using a long straight edge and ruler. It should vary no more than 3mm in height over 1m. Uneven floors should be repaired using a self-levelling compound or plywood.

Inspecting Your Solid Wood Floor

On receipt of your new real wood floor, it is important to check a few pieces before doing anything. Open one box carefully and lift out some planks. Check over the grading, finish, and quality to ensure that the product is as you expected. Natural wood can have huge variances from batch to batch, especially in rustic grade wood flooring, so it is important to check that you are satisfied with your new hardwood flooring before acclimatisation and installation. Most reputable wood flooring companies will require their products to be inspected by the customer prior to installing a real wood floor. Once permission has been granted to the installer to fit the floor, it would be very difficult to change or refund it for any reason other than a defect that develops after the installation.

How To Acclimatise a Solid Wood Floor

Once the conditions in the room of installation are correct, the floor can then be acclimated. This is an important stage as it balances the moisture levels of the wood flooring with the moisture levels in the room. This will help to minimise any expansion or shrinkage that the hardwood floor may do after installation. Incorrect acclimatisation can lead to your wood floor warping, bowing or increase the chances of issues after installation.

Only once the site condition checks have been confirmed as correct, should you then store the solid wood flooring packs closed in the boxes, flat in the room of installation. Ensure packs remain sealed and stacked no more than 3 packs high. Leave gaps of at least 4cm between all piles. This will ensure that the air is sufficiently circulated around each box and that the planks will retain as much as possible of their original shape.

The packs should be left to acclimate for a minimum of 7 days. Normal living conditions must be maintained. If it's a room where the heating is always on, leave the heating on as normal. The idea is to let the wood floor expand or contract before you install it. This will help to reduce how much movement the floor makes after installation.

To learn how to acclimate laminate flooring, check out our FAQ's.

The Solid Wood Flooring Installation

Preparation & Expansion

Remove all existing underlay and floor coverings to ensure that you have a strong and level base for installation. As there is expansion required for solid wood flooring, a gap will be required around the perimeter of your installation. The correct expansion gap for wood flooring is 10-12mm. This must be completely maintained around the perimeter of the floor, which must not touch anything along the edges. This includes walls, skirting boards, radiator pipes, door frames, connecting floors and anything else that might restrict the wood floor from expanding.

Solid wood flooring expands mostly across the grain and because of this we recommend that installations should run no more than 5m across the grain in any installation. The maximum recommended length for real wood flooring installation is 7m.  If you do need to break up a long run we recommend doing this with expansion bars. These are mostly used in doorways and are perfect for hiding expansion gaps. In very large rooms this is not always possible to do so building expansion into an installation can be done by using 1/2mm spacers in between individual rows. These are extremely hard to see but will allow for the extra expansion that a large floor installation may require.

How To Lay Solid Wood Flooring - Installation Methods

Solid wood can be installed onto 2 sub-floor types. Concrete and Plywood. We don't recommend installing over chipboard and instead would suggest a floating floor such as engineered wood flooring or laminate flooring.

Installing Solid Wood Flooring Onto Concrete


Use a flexible wood to concrete adhesives such as Laybond or Soudal Polymer. Starting in one corner of the room, spread in excess of 2 board widths of adhesive along the starting wall sub-floor using a 3mm toothed trowel. Then place the first row of flooring into the glued area with the tongue facing away from the wall. Use 10mm spacers against the wall to ensure that the correct expansion gap is maintained and to help straighten out any unevenness in the wall. When laying the second row ensure that joints are at least 150mm apart from the first row.

If you are installing long plank boards, often pre-cut smaller boards are included to enable you to begin a new row with staggered joints. Continue using this method of spreading the glue 2 board widths wide and installing boards, ensuring that expansion gaps are maintained around the perimeter.

Installing Solid Wooden Floors Onto Plywood

Use an overlay flooring nailer (also caller a porta-nailer). Place 10mm spacers against the wall running parallel with the direction of your installation. Then install the first row of flooring with the tongue facing away from the wall, and fit in place by using the flooring nailer. Nails should be used every 200mm or a minimum of 2 nails on boards shorter than 400mm. When laying the second row ensure that short end joints are at least 150mm apart from the first row joints. If installing fixed length long plank wood flooring, some pre-cut smaller boards may be included to enable you to begin a new row with staggered joints. Continue using this method of nailing, ensuring that 10mm expansion gaps are maintained around the perimeter.

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