Hello
I’m new to this site but hoping someone can throw some light on a difficult problem on kitchen drainage.
This is in my father-in-law’s 4th floor flat in Paris, in a modern block (1990’s)
The roots of the problem are multiple.
Really poor installation with an almost horizontal run of 4m+
All in 40mm pipe as is usual in France. (Unfortunately).
No vent as is usual in France. (Double Unfortunately).
No space behind cabinets for even a 40mm pipe
All traps are completely clear.
I have included a couple of sketches. Dimensions are a little exaggerated but it shows the challenges.
The initial problem 1
Washing machine spitting water back out from stand pipe.
Having excavated the (glued-in) kitchen units away from under the work top I find the following
Problem 2 -
As the waste has been spitting out water for years, the plasterboard wall was shot.
That meant the pipe clip giving the pipe 6cm of drop in 4m had come out.
So there was a negative drop on the pipe for about 2.5m which was full of stagnant water (from the dishwasher draining back the wrong way following the pipe clip falling out of the wall).
Problem 3 -
The washing machine was emptying itself onto the floor out of the waste stand pipe (40mm !)
i.e. waste water just not capable of pushing round a horrible trap and then its got 3m of stagnant water to push out too.
Problem 4 - Trap and bends creating too much back pressure?
It might be ok for a shorter horizontal run but its still got 4m to go.
Problem 5 - 4mts of horizontal run.
Problem 6 - Also its creating back pressure as there is no vent.
Problem 7 - Its all glued! Even the traps which means opening it up with a nibbler if I need to change anything as its under the kitchen units.
And no rodding points.
SO
I've got the pipe back on the wall with a solid support underneath it.
The pipe is now draining.
I've increased the hight and width of the downpipe (50mm) just to increase its volume for full waste flow from the machine pump.
But at full pump flow, there is still a bit of water blowing back out.
If I seal the outlet pipe into the standpipe, then it creates problem 8
Problem 8 -
The dishwasher has a shorter stand pipe.
Water is now dribbling out of this - I guess due to no vent (problem 6) and higher water level in washing machine stand pipe due to lack of flow.
The obvious solution is to rip the whole kitchen out and start again. But that is the nuclear option!
I have no space behind the units for pipes - its all at floor level under the cabinets (with the exception of the standpipe section.)
I can’t move the units forward as they are part of an angle unit.
I can’t vent the outlet drain pipe as it is not on an outside wall.
Its pretty difficult getting rid of some of the bends as there is no height and I need an access point for the traps.
Remedy?
I'm going to increase the height of the dishwasher stand pipe and keep my fingers crossed.
Maybe there is a blockage further down stream somewhere else in the building - but we don’t have any access to that.
I could make all the connections closed (jubilee clips over rubber hose connectors) but that will create a lot of pressure in the system I fear.
And lots of gluggiing through the sink trap.
Maybe someone has a better idea?
Many thanks
I’m new to this site but hoping someone can throw some light on a difficult problem on kitchen drainage.
This is in my father-in-law’s 4th floor flat in Paris, in a modern block (1990’s)
The roots of the problem are multiple.
Really poor installation with an almost horizontal run of 4m+
All in 40mm pipe as is usual in France. (Unfortunately).
No vent as is usual in France. (Double Unfortunately).
No space behind cabinets for even a 40mm pipe
All traps are completely clear.
I have included a couple of sketches. Dimensions are a little exaggerated but it shows the challenges.
The initial problem 1
Washing machine spitting water back out from stand pipe.
Having excavated the (glued-in) kitchen units away from under the work top I find the following
Problem 2 -
As the waste has been spitting out water for years, the plasterboard wall was shot.
That meant the pipe clip giving the pipe 6cm of drop in 4m had come out.
So there was a negative drop on the pipe for about 2.5m which was full of stagnant water (from the dishwasher draining back the wrong way following the pipe clip falling out of the wall).
Problem 3 -
The washing machine was emptying itself onto the floor out of the waste stand pipe (40mm !)
i.e. waste water just not capable of pushing round a horrible trap and then its got 3m of stagnant water to push out too.
Problem 4 - Trap and bends creating too much back pressure?
It might be ok for a shorter horizontal run but its still got 4m to go.
Problem 5 - 4mts of horizontal run.
Problem 6 - Also its creating back pressure as there is no vent.
Problem 7 - Its all glued! Even the traps which means opening it up with a nibbler if I need to change anything as its under the kitchen units.
And no rodding points.
SO
I've got the pipe back on the wall with a solid support underneath it.
The pipe is now draining.
I've increased the hight and width of the downpipe (50mm) just to increase its volume for full waste flow from the machine pump.
But at full pump flow, there is still a bit of water blowing back out.
If I seal the outlet pipe into the standpipe, then it creates problem 8
Problem 8 -
The dishwasher has a shorter stand pipe.
Water is now dribbling out of this - I guess due to no vent (problem 6) and higher water level in washing machine stand pipe due to lack of flow.
The obvious solution is to rip the whole kitchen out and start again. But that is the nuclear option!
I have no space behind the units for pipes - its all at floor level under the cabinets (with the exception of the standpipe section.)
I can’t move the units forward as they are part of an angle unit.
I can’t vent the outlet drain pipe as it is not on an outside wall.
Its pretty difficult getting rid of some of the bends as there is no height and I need an access point for the traps.
Remedy?
I'm going to increase the height of the dishwasher stand pipe and keep my fingers crossed.
Maybe there is a blockage further down stream somewhere else in the building - but we don’t have any access to that.
I could make all the connections closed (jubilee clips over rubber hose connectors) but that will create a lot of pressure in the system I fear.
And lots of gluggiing through the sink trap.
Maybe someone has a better idea?
Many thanks
