Griffo wrote:
I live in an old Victorian property. The floor is pine boards. I
want to lay an engineered wood floor but there is a dip of about
5-10mm at the foot of the stairs. I have been told that if I don't
nail this area but just leave it, the board will settle over time. Is
that right or should I put some battens down?

Depending on what the engineered flooring is, it might, but more likely
it won't--at least in a way you want it to. At best it might simply
flex a little, at worst it will crack the laminate, in the middle it'll
not only flex but squeak besides.

Need to have a level, smooth subfloor. Consult the manufacturer's
instructions for how to lay the product.

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