A complete guide on how to install solid wood floors, written by our expert team.
Installing wood flooring, for the most part, is actually quite simple. However, there are some important rules to follow and failure to do so can lead to expensive problems. Ensure that you follow our guide and you will have a problem free floor.
- Hand Saw
- Measuring tape
- Knee Pads
- Moisture Metre
- Pull Bar
- Electric Chop Saw (to replace the hand saw)
- 2m Long Spirit Level
Site Conditions For 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 a 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. 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 metre. NB Some metres 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-leveling 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 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 perimetre 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 longer 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.
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.
When installing solid wood flooring onto concrete, you must 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.
When installing solid wood flooring onto plywood, you must 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 fis 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.
- Work from 2-3 open boxes at once, so that you can spread the full natural range of colours.
- Check every board before installing. Naturally imperfect boards are always possible.
- Installing with randomly placed joints often looks better and ensures less waste.
- The floor should not touch anything at the perimeter. Check accessory ranges for products to hide expansion, such as door bars, beading, and radiator collars.
- Underlay should not be used with solid wood flooring unless the risks have been explained to you.