Hi Folks,

"BigWallop" wrote in message
...
And if you cut to the length of the spacing of the joists, how much of
each
board do you loose ? Quite a bit I'd imagine. So if you keep all the
tongue and grooves together, no matter where the joint ends up, you be
able
to board out the whole loft, right up to edges, and it should all be
strong
enough for you to use as storage space.

When one board ends up with an overlap on one joist, then the other board
is
banged in against the edge of it, it will still have enough strength to
take
the weight of an average bloke, even if the joint ends up in the middle of
the gap in the joists, because of the construction of the boards.

I'm probably too cautious but I always make sure that any joint is supported
with
a noggin if it doesn't always work out to be over a joist.
True, the chances of someone jumping up and down on it are slim, until my 15
year old
lad ran along our upstairs corridor and jumped and landed on a joint with
such force
that he broke the tongue&groove! He then reported the fact that "the carpet
gave way"
which I always find amusing!

Simplifying for ascii-art, the tongue is like a "TTT" and the groove like a
"GGG". With
any downward pressure the weight must be on the lower edge of the groove's
"" ?
Therefore half the wood thickness is supporting the 15 year old landing on
it... snap.

If you are going to board an area for walking on, methinks it won't be that
much extra
effort to put (say) four by two noggings to support some part of a tongue
and groove
joint.
If it were to snap, consider how far the person may fall when they slip down
through the
crumbling plasterboard. In my house the worst drop would be through the
ceiling above
the stairwell... about 3 metres.

Just my opinion.

Mungo