I am putting a new basin into my toilet room. The toilet current connects
into one of these http://www.screwfix.com/sfd/i/cat/00/p1063600_x.jpg on the
main soil stack (well almost that but with what looks like screw fittings).
I want to connect my 32mm waste from the basin into it. Do I just cut out
the access hole and then use a reducer to put in my 32mm pipe? How do you go
about cutting the middle of the access hole and how do you bond the waste
pipe to the soil pipe - solvent?

Cheers for any advice.

Rob

On Tue, 22 Nov 2005 00:13:04 -0000 someone who may be "Rob Convery"
wrote this:-

I am putting a new basin into my toilet room. The toilet current connects
into one of these http://www.screwfix.com/sfd/i/cat/00/p1063600_x.jpg on the
main soil stack (well almost that but with what looks like screw fittings).
I want to connect my 32mm waste from the basin into it.

I wouldn't want to do that. Connections should not be made to the
stack within 200mm of the centre point of a lavatory connection.
This is to avoid the possibility of the lavatory discharge blocking
or obstructing smaller waste pipes.

Instead make the connection at least 200mm above or below the
lavatory connection, using a suitable boss. Whether it is above or
below depends on your plumbing. The hole can be made with a suitable
hole cutter (into a plastic stack).

There are patent fittings to avoid this, but I suspect it would mean
dismantling the stack to insert one, which you may not want to do.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"David Hansen" wrote in message
...

I wouldn't want to do that. Connections should not be made to the
stack within 200mm of the centre point of a lavatory connection.
This is to avoid the possibility of the lavatory discharge blocking
or obstructing smaller waste pipes.

Instead make the connection at least 200mm above or below the
lavatory connection, using a suitable boss. Whether it is above or
below depends on your plumbing. The hole can be made with a suitable
hole cutter (into a plastic stack).

There are patent fittings to avoid this, but I suspect it would mean
dismantling the stack to insert one, which you may not want to do.


Thanks for that, sounds like the easiest thing is just to join the waste
with the basin in the bathroom which I am pull the water feeds from. The
amount of waste will be minimal as its only for washing hands so should be
fine

Rob Convery wrote:
I am putting a new basin into my toilet room. The toilet current connects
into one of these http://www.screwfix.com/sfd/i/cat/00/p1063600_x.jpg on the
main soil stack (well almost that but with what looks like screw fittings).
I want to connect my 32mm waste from the basin into it. Do I just cut out
the access hole and then use a reducer to put in my 32mm pipe? How do you go
about cutting the middle of the access hole and how do you bond the waste
pipe to the soil pipe - solvent?

That's just about it. Cut out the hole with a padsaw or something,
and cut the ragged edge off. You could go into the soil stack
using a strap boss.

David Hansen wrote:
Connections should not be made to the
stack within 200mm of the centre point of a lavatory connection.
This is to avoid the possibility of the lavatory discharge blocking
or obstructing smaller waste pipes.

Instead make the connection at least 200mm above or below the
lavatory connection, using a suitable boss. Whether it is above or
below depends on your plumbing. The hole can be made with a suitable
hole cutter (into a plastic stack).

If the connection is made opposite the lavatory one, 200mm below,
that seems to be in the perfect position for being blocked! That
said it doesn't seem to happen IME.

On Tue, 22 Nov 2005 07:42:03 +0000, David Hansen
wrote:

There are patent fittings to avoid this, but I suspect it would mean
dismantling the stack to insert one, which you may not want to do.

There is/was a sort of drilled rubber bung type affair for doing this.
Haven't seen them for a few years (but then again I haven't been
looking for them.)

sponix

On Tue, 22 Nov 2005 08:57:48 -0000 someone who may be "Rob Convery"
wrote this:-

Thanks for that, sounds like the easiest thing is just to join the waste
with the basin in the bathroom which I am pull the water feeds from.

You may need anti-siphonage traps on both basins if you do this.
Single stack plumbing works well when someone who knows what they
are doing is designing it. However, the various recommendations are
there for a reason.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Tue, 22 Nov 2005 09:18:29 +0000 someone who may be Chris Bacon
wrote this:-

Connections should not be made to the
stack within 200mm of the centre point of a lavatory connection.
This is to avoid the possibility of the lavatory discharge blocking
or obstructing smaller waste pipes.

If the connection is made opposite the lavatory one, 200mm below,
that seems to be in the perfect position for being blocked!

After falling for over 100mm the lavatory discharge is presumably
going vertically and thus unlikely to block a smaller branch. If the
smaller pipe is connected closer than 200mm then I imagine there is
still a horizontal component to its motion and so it may block the
smaller branch.

Having thought about it a bit more I suspect that the 200mm above
recommendation is to avoid siphoning water out of the trap in the
smaller waste.

That said it doesn't seem to happen IME.

That demonstrates that those who cam up with the recommendation were
right:-)


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54