I'm about to move a utility room sink and washing machine. The
existing drain for both goes into a downpipe from an upstairs toilet.
I can either extand the drains to run into the same place or use an
alternative, this raises a couple of questions:-

How can one tell where an outside drain grid goes to? Our kitchen
sink currently empties into one of these though I can't be
absolutely sure this is legitimate/allowed. If I could use a
similar one for the moved sink and washing machine it would make
for much simpler routing of the wast pipe[s].

If the above is 'not allowed' then what is the recommended minimum
slope for a sink waste? It will need to run about 3 metres
horizontally and will have a short 'zig-zag' to go around a
projection in the wall it would need to run along.

--
Chris Green
·

On an equal tee the branch makes an angle of 92.5° so that would suggest a minimum of 2.5° . If I recall correctly even the right angled bends are nearer 93°.

Richard

On 23/07/2019 18:44, Chris Green wrote:
I'm about to move a utility room sink and washing machine. The
existing drain for both goes into a downpipe from an upstairs toilet.
I can either extand the drains to run into the same place or use an
alternative, this raises a couple of questions:-

How can one tell where an outside drain grid goes to? Our kitchen
sink currently empties into one of these though I can't be
absolutely sure this is legitimate/allowed. If I could use a
similar one for the moved sink and washing machine it would make
for much simpler routing of the wast pipe[s].

If the above is 'not allowed' then what is the recommended minimum
slope for a sink waste? It will need to run about 3 metres
horizontally and will have a short 'zig-zag' to go around a
projection in the wall it would need to run along.


A bit of synchronisity there, I just posted about a similar thing.

AJH