Mark wrote:
I'm planning on laying a t&g oak floor.

The existing floor is concrete and not particulary smooth.

I'm doing my homework first to establish the correct procedure.
Is it similar to laminated flooring with a dpc membrane and soft underlay
boards?
Is it normal to glue the boards to each other?

While it is possible to lay an oak floor as a glued floating floor, it
is not recommended. This is because while laminate behaves in a uniform
way in response to humidity changes, oak expands and contracts
non-uniformly. Depending on how your oak has been sawn, the stresses in
a floating oak floor may result in it coming apart over time.

There are 3 recommended methods for laying an oak floor on concrete:

1. Battens, then secret nailing. This is simple, reliable and always
works. Putting down the battens takes a bit of time, but once they're
down, the nailing is pretty quick (with the correct nailer that is).

2. Double sided adhesive underlay. This is like a 3mm thick stretchy
underlay, with adhesive both sides. You stick the underlay to the floor,
then stick the oak to the underlay. This only works if you have a
smooth, dust-free concrete floor.

3. Instead of using battens, you use lines of special rubbery glue. You
apply these at 30cm spacing, and lay your oak floor onto the glue lines.
The glue remains flexible, allowing movement in the oak floor. This
method can be used on more uneven floors, but the concrete still needs
to be dust free, so you may need to seal it.

For my money, I'd batten with 50 or 75mm battens, and insulate between
the battens with kingspan.


--
Grunff