1. Nail Down
This floor is installed onto timber batons fixed to a concrete sub floor using the hidden nailing method to fasten the floor through the tongue to the baton. This traditional way of installation allows for a cavity space between floor and concrete but should not be installed above bare earth as used to be practiced in former times. Modern kiln-dried flooring does not allow for moisture rising from the ground even if the floor is vented on the sides. The nail down floor is more noisy when walking on it giving it a traditional feel.
2. Glue Down
A glue-down floor does not require the construction of a timber sub structure. The flooring boards are glued directly to the screed. The quality of the concrete screed as well as the level of the floor have to be perfectly straight to successfully install this type of flooring. The floor follows the level of the concrete screed making adjustments in height (as with a nail-down floor) impossible. This type of flooring is very quiet to walk on and gives a wonderful solid feel under foot. The glue down floor is best used where height presents a problem in existing or new homes.
With this type of flooring the planks are glued together on the tongue and groove. It means that the floor planks are not fixed to the screed/sub floor, it literally floats. It is the most cost effective way of laying a floor. It allows the wood to expand and contract freely without being restricted. A 10mm expansion gap is left around the floor to allow for movement, the floor itself is held down by skirting, which also covers the gap.