In message , The Natural Philosopher
writes
On 01/11/2020 14:55, Andy Burns wrote:
John Rumm wrote:

Do you take similar care walking over a floor in a modern house?
Because the same arrangement of floor boards exists there.
Chip floorboards are 22m or 38mm though, compared to 18mm for
loftboards.

Remember you are talking about a 2' wide board adjacent and
interlocked with another, spanning one joist space - so there is no
reason for it to give at the edge.
I have certainly managed to crack the odd tongue off my loftboards

18mm is also ok for floors

ISTR 22mm is required for ground floor.


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Tim Lamb