Richard Savage wrote in message
...
Brother-in-Law has installed a floor using Wickes' Kiln Dried Tongue and
Groove flooring. He used a secret nailing machine to nail through the
tongues and a strap thing to compress the boards. Neil was afraid
that, being kiln dried, the boards would swell. But a number of the
boards have shrunk and split. Wickes' sent a bod to inspect the floor
and told Neil that the boards must be fixed with nails through the face
of each board into the joists and are refusing to replace it. And they
say that the packet states this. Unfortunately Neil has chucked the
wrappings but when he went to check in a Wickes' he noticed that the
labels are a different colour (red rather than yellow or vice versa) and
do say that you must nail through the face. Neil's observation (minus
expletives) is what is the point of fixing T+G with visible nails?
Wickes' declined to comment.

The method of fixing isn't going to make much difference if the material is
too wet or too dry for the location. IME, if you nail through the faces, you
get more splitting.
"Kiln dried" implies less than 15% moisture content, but how much less is
never specified. A first floor would probably shrink, whereas a ground floor
covered in vinyl would be more likely to swell because the timber would be
more attuned to outdoor conditions.