"John Rumm" wrote in message
...
Arthur wrote:

I am not too confident of leaving the holes unblocked as I opened up one
of
them into a
slot and it is now about 1/3 of the joist heght in depth on one side.

Given that putting a pipe through a hole will do nothing to restore the
structural strength lost from making the hole, it would be best to not
make hole that you are not happy about leaving unsupported - since this
is what they will be, even with a pipe through it.

How close to the end of the joist are you? How long is the joist in total?

Although the building regs give guidelines about how deep holes can be.
and where in the joists you ought make them, they are making the
assumption the joist is correctly sized for the job in the first place.
This is often not the case in bathrooms where they may actually be well
over size simply for the reason they need to match all the others in
height.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Sorry for being slow to reply.

The holes are all no nearer than 160mm (about 17") from the wall.
However, now that I think about it, the joists from the adjacent room are
protruding
through the wall some 10-12". The joists in question are 6" x 2".

If I saw the holes into slots and then use 2 screws each side of the notches
would that
be strong enough?
BTW, The pipes will run under 22mm chipboard flooring where only people will
impart weight.

Thanks.

Arthur