Engineered flooring can be installed in a number of ways according to preference and to the type of sub floor onto which it is being laid.Floating FloorIf you wish to lay an underlay beneath your floor for the purposes of soundproofing, then your floor will be ‘floated’ on top. This means that the tongue and groove joints between each plank are glued together using PVA adhesive and the planks are laid over an underlay, leaving the new floor independent from the sub floor.Adhered FloorIf your floor is being installed onto concrete, ply, or a suitable form of underfloor heating, it will be fully glued down using a suitable flexible adhesive. The adhesive is usually trowelled onto the sub floor and the wood flooring is placed into position on top and left to set.Secret Nailed FloorIf your floor is being installed directly onto joists or ply, it will be secret nailed. This means that a nail is driven through the tongue of each plank at a 45 degree angle to the timber subfloor. If you are nailing directly to the supporting joists your timber floor will need to be a minimum of 18mm in thickness or 20mm if your joist centres are wider then 300mm, and you will need to insert building paper between the floor and the joists to prevent the surfaces rubbing together and squeaking.