4 inch run

[jaydebruyne]

Went to look at a job last week - leak from a sanipro unit on the first floor.. turns out that the unit is defective. When I investigated the pipework the installer has run the waste outlet from the macerator into a rainwater pipe outside!!!

I advised the lady how bad this was and that it needs to be rectified asap.

Anyway, she wants me to see if I can connect her bathroom to the main waste system. As far as I could see there wasn't a stack, just a 4inch elbow sticking out the floor on the ground floor for the downstairs loo connected to a run of 4 inch under the floor.

What I'm going to do on Monday is open up her celiling to see if there is enough height to run some 4inch under the 1st level flooring, open up the floor where this 4inch run is on the ground floor and tee into it.

But this would need to be vented wouldn't it? I need to check if there is a vent which serves a few houses (terraced) - as far as I can remember from college there can be one vented stack per 6 houses I think.

The more I think about this job the more I just don't want to do it.

What's the min fall for about 4 meters of 4inch before a vertical drop to the pipework under the floor? Is it even possible to tee into horizontal 4inch with a vertical branch? (Is the tee swept?)

 

[Jones82]

23mm per metre fall on above ground drainage if I remember right. I would vent the stack with a n internal durgo, automatic air vent, at least, Make sure the durgo is accessible as it will want replacing or repairing one day. Yes tee's are swept.

 

[jaydebruyne]

23mm per metre fall on above ground drainage if I remember right. I would vent the stack with a n internal durgo, automatic air vent, at least, Make sure the durgo is accessible as it will want replacing or repairing one day. Yes tee's are swept.

The AAV needs to be on same level as the toilet doesn't it? Has to be at the highest point of the run?

Cheers Jones82

 

[Jones82]

Yes above the height of the cistern at the very least other wise you might get leaks if the toilet blocks!

A good place is usually the loft as access is easy when the aav needs replacing, please don't tile it in a pipe box, as I've seen that done many times

Just had a thought, maybe run externally and come back in if possible, always the easiest and best way if possible

 

[unguided1]

Above the highest outlet, so needs to be above the basin waste!

 

[jaydebruyne]

Above the highest outlet, so needs to be above the basin waste!

I think she may just have to stick with her saniflo- need the keep the AAV internally and she's not gonna want a vertical bit of 4inch pipe with AAV sticking out above her tiled boxing lol

The only way it could be done externally is by bringing a branch up through the roof of the extension which the run would pass through but then she'll need a roofer too! Oh dear...

 

[unguided1]

How old is the property? Is it a semi or a terraced? Are you sure there is no stack?

 

[jaydebruyne]

Terraced.. not sure how old. Gonna have a proper look Monday but owner is sure there isn't one..

 

[unguided1]

Ok back in the day on old council terraced houses, they used to ave one vent pipe to four four properties, although I'm sure I've seen some with six! Ave a look at the other properties

 

[rpm]

Went to look at a job last week - leak from a sanipro unit on the first floor.. turns out that the unit is defective.

Here if you need me mate.

 

[tolly]

18mm/m minimum fall

 

[jaydebruyne]

Here if you need me mate.

There aren't any circumstances you can run a sani unit (toilet) into a rain water system is there? I know the answer but just need to be 110% certain by hearing it...

 

[chris watkins]

There aren't any circumstances you can run a sani unit (toilet) into a rain water system is there? I know the answer but just need to be 110% certain by hearing it...

NO - come on Jay have a bit of confidants

If it is an old house is the drainage system a combined or separate one?

Just for the record a Durgo / A.A.A.V does not vent a stack ! as it only allows air in not out. Which could be an important consideration if there is a pumped waste.

4M of smooth bore 110mm soil laid horizontally would need no more than a turn of a bubble :wink_smile:

Take some photos Jay I can't understand what you are proposing.

 

[joni os]

Tee into horizontal 4" with vertical branch. If horizontal run is busy sewer this would work, but where horizontal flow is intermittent it may be better to keep branch horizontal then connect with radius bend to vertical drop.

 

[rpm]

There aren't any circumstances you can run a sani unit (toilet) into a rain water system is there? I know the answer but just need to be 110% certain by hearing it...

As Chris said earlier you are 110% correct.
Last one I saw was an Indian restaurant running the waste from both the Male & Female toilets to the rain water system. I told them it all had to be changed and was kicked off site. 2 days later the placed was closed for business following a quick phone call to the council.

Wonder who made that call? :rockon2: