Suitable Subfloors

Covid 19 Update Read More

We are open for business as usual (although there here is nothing usual about this situation) with our transport company (Brooks Transport) who are designated by the government as critical to the covid response. We are still delivering direct to door or site, (however collections or visits to the warehouse are not possible.) Our IT systems allow us to work from home so our staff are protected. Please Call or Email Us for samples or orders. Our factories are back to full capacity and the supply chain is operating effectively which can be seen here. As a trade supplier we have a minimum requirement of 50m2 for any samples and supplies. Please call 01666 504015 if you require less. For Government advice please click here. Even with these steps we have made, we must pull together, support one another, and get through this as a group, a family, and feel proud to say to our wider community we are critical to the Covid-19 response, and we will support it for as long as we are able. Stay safe, stay well, look after yourself, and each other.

The Building Centre will be open fully with the café back and exhibitions in place from Monday 12th April 2021. In the meantime, you can book visits in advance by contacting The Building Centre directly on 020 7692 4000. Please note that we do not have any representatives based at this showroom, but you can call us during your visit to talk through the options on display on 01666 504 015.

The Tetbury showroom is strictly by appointment only, maximum of two people with social distancing and face coverings required. Please call 01666 504 015 to book an appointment.

Suitable Subfloors

Subfloors can be troublesome if the correct procedures aren’t followed.  This is because; whatever goes on top of the subfloor will be affected by it.  Damp or damaged membranes can allow moisture to rise upwards. 

In any case it is always recommended that you have an experienced wood floor fitting specialist install your floor.  The preliminary work they carry out on the suitability of your subfloor is of paramount importance to the longevity of your new wood floor.

There are five basic types of sub floors that you can use to install a wooden floor:

  • Concrete screeds
  • Joists
  • Ground floor joists
  • Old Floor Boards 
  • Chipboard or plywood


Concrete screed floors can vary in condition and levels.  If your subfloor isn’t flat and smooth, you can use self-levelling compounds to rectify the issue.  It is also crucially important to check the moisture content of concrete subfloors.  Use a hygrometer (as described in BS8201 – Code of Practice for Installing Wood Flooring) to check moisture levels within the subfloor, and thusly whether that screed requires additional drying or introducing a sealant or Damp Proof Membrane prior to fitting a wood floor.


If you’re fixing floorboards directly to joists, you can either use secret nails or screws. These are applied using a purpose made nail gun or screw fixer which is set at a predetermined angle. This ensures the groove of the next board can be fitted up without the screw or nail showing.  Most of our engineered floor boards that are at least 19mm thick are structural and can be fitted in this manner as long as the joists are no more than 300mm from centre.

Old Floor Boards: 

Generally old floor boards will be pine or cheap softwood.  A new hardwood floor can either be secret nailed/screwed, floated or glued directly onto these boards if the conditions are correct.  If your existing floor is uneven or damaged you may need to replace it with ply or chipboard prior to fitting a new wood floor.

Chipboard or Plywood Floors:

Chipboard and plywood are suitable subfloors for wood flooring providing they are of sufficient thickness to support the floor and are of good quality.  For fitting block parquet flooring a minimum thickness of 18mm is required and it must be marine grade ply.