Shower drain

Feb 13, 2022
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My shower takes forever to drain . The pipes could probably do with a good clean out, however I was looking under the van for another reason an noticed that the drainage pipe runs up hill from the bottom of the shower drain??! Also, on a few occasions I've had unexplained water appear in the shower tray. I haven't yet looked at the pipe work in detail but on other forums I see that sink water can end up coming up into the shower. I am minded to modify this odd setup and create a separate drain pipe for the shower. Has anyone done this before?
 
Mar 14, 2005
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Yes there have been previous posts on the same subject. The only problem I recall was some have found they couldn't get two pipes into one waste container. one solution was to create a removable y piece to join both outlets before entering the waste container.

One other possible problem can be the corrugated pipe the caravan manufacturers are keen on using, Some debris can collect in the groves and begin to obstruct the free flow.

Some people have replaced the corrugated pipe with standard plastic plumbing pipe.
 
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Jun 16, 2020
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Yes, it does mean crawling under the van though. I change the pipe run for smooth bore domestic waste push fit. I forget how I connected to the shower outlet. Must have got an adaptor or fitted a domestic outlet. But I reverted to convoluted to get through the chassis. It was years ago and it still works a treat. I also used plastic spacers to achieve a steady fall.

Another way to improve things, but not as good, it to carefully put some bleach or drain cleaner down, followed by a hose held in the waste with a rag around to form a seal while someone turns the tap on to flush the rubbish.

John
 
Feb 13, 2022
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I'm thinking of replacing the shower drain with with something like this The current one goes straight down with an elbow on it, leaving less space for a descent to the waste outlet. Another option I've seen is a drain with a built in pump, although less keen on that because it's another load on the battery when I'm off grid.
 
Jan 19, 2002
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I thought it was more usual for the two sinks to outlet together and the shower to be separate, but maybe this depends on the van layout. However finding my sink drainage very slow, (and like many others the flap covers on my drain holes cracked off ages ago) I bought a couple of cheap ‘caravan waste end plugs’, pushed them on to block the outlets then carefully filled both sinks and shower, let it soak and then removed the plugs. Yuk! Now the flow is good again and this has become one of my regular post-trip tasks.
 
Feb 13, 2022
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I thought it was more usual for the two sinks to outlet together and the shower to be separate, but maybe this depends on the van layout. However finding my sink drainage very slow, (and like many others the flap covers on my drain holes cracked off ages ago) I bought a couple of cheap ‘caravan waste end plugs’, pushed them on to block the outlets then carefully filled both sinks and shower, let it soak and then removed the plugs. Yuk! Now the flow is good again and this has become one of my regular post-trip tasks.
I’m not sure if the exact setup. I will examine more thoroughly at the weekend. I will give the pipes a clean, but i think there biggest improvement to shower drainage would be to eliminate the uphill section of pipe.
 
Jan 3, 2012
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We had the similar problem on our caravan in the end the shower got it own outlet so that means we had three outlets on the side of the van but i am not handy with my hands my caravan engineer sorted for me so good luck
 
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Sam Vimes

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Sep 7, 2020
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My shower takes forever to drain . The pipes could probably do with a good clean out, however I was looking under the van for another reason an noticed that the drainage pipe runs up hill from the bottom of the shower drain??! Also, on a few occasions I've had unexplained water appear in the shower tray. I haven't yet looked at the pipe work in detail but on other forums I see that sink water can end up coming up into the shower. I am minded to modify this odd setup and create a separate drain pipe for the shower. Has anyone done this before?
Yes I had to do this on our new caravan on which the pipework was badly thought out. The kitchen sink was connected to a T fitting, the other side of which was the shower tray waste. When we emptied the sink the water just flowed from one to the other before going out the side.

I got underneath and reorganised the layout such that the kitchen sink and shower waste were seperated then connected to a Y piece before going out into the wastemaster. No problems since.

I also ensure that the pipes from the outside connections on the van to the wastemaster don't actually go into the waste water as it gets full.
 
Nov 11, 2009
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In my last two vans I separated the shower from the other drains, but still retained the two outlet arrangement.
 
Nov 16, 2015
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Along with the others changes to the pipes , I carry a small hand water plunger , cast about £2.00 and as the wastes runs slow a quick pump on the shower, sink , and the waste runs away quick again
 
Feb 13, 2022
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How difficult is removing the shower tray? Has anyone done this? To change the drain it looks like the tray needs to come out unless I cut an access hole in the floor which I’m not overly excited about. Wouldn’t mind replacing the tray as it looks like it’s been repaired at some point but don’t want to do it if I’m going to have to dismantle half the van to get it out.

Most simple solution I can see is the Whale Gulper pump, but they are pretty expensive at £104 . Can’t find anything else which does the same job any cheaper.
 
Nov 11, 2009
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Why not go for the simpler solution and modify the pipes underneath. Most respondents who have done that have had the problems of back flow and speed of outflow go away.
 
Feb 13, 2022
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Why not go for the simpler solution and modify the pipes underneath. Most respondents who have done that have had the problems of back flow and speed of outflow go away.
I hope that I can do this, but I fear that with the design of the trap being straight down and then an elbow, there won't be enough height to slope down. I'll have a look around tomorrow and report my findings.
 
Feb 13, 2022
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Had a closer inspection today and I can see that there is plenty of room for a down hill slope to the drain. Oddly, the wash bason has it's own outlet, but the shower outlet joins the kitchen sink pipe on a T piece. I plan to install an third outlet and install some 32mm Floplast PVC pipe using spacers for the brackets to create a downhill slope all the way. I've started videoing the process as I've not found any Youtube videos on it, so thought I'd make one.

Also have been clearing out a load of hair in the shower trap. Dug it out with a screwdriver. Mostly hair from the previous owners. Jobs like that make me literally feel sick. Taking hoover and genny over tomorrow, don't want to put my hands anywhere near what I have dug out of there. Will also take some drain cleaner.

One question for those who have done the job. Should I be able to join the Floplast pipe directly to the new waste outlet using the solvent cement?IMG_0502.jpeg
 
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Jan 19, 2002
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Maybe re use a bit of push fit just in case you need to separate it at any future time, for e.g removing any plug hole debris from underneath? Depending on layout and sticking with the two outlets can you combine the two sinks and leave the shower as the single?
 
Nov 11, 2009
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When I separated the drains I used push fit connections. As long as the run is well supported by brackets they are the best as any future maintenance is so much easier than with solvent bonded joints.
 
Mar 14, 2005
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Looking at your picture it suggests to me that somebody has been there before you, The L bend connection to the flexipipe does not look original factory fit, and the square of plywood through which the pipe passes also looks like a retro fit, I would be inclined to disconnect the flexi pipe, and remove the plywood square and see what you find behind it, Once the plywood square is removed you may get access to the shower drain, if you can then I suggest you replace all of the fittings from the drain, and run fresh piping using blocks to ensure a downhill flow. Is your shower on the side or the rear of the van?
 
Jul 18, 2017
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Pity you cannot fit a U bend trap there to prevent water coming back into the shower and also preventing smells on hot days.
 
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Mar 14, 2005
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A "U" bend will not stop back flushing of water. The purpose of a "U" bend is provide an air lock to stop smells from waste pipe systems and sewers from emerging back into the living space. Some "U" bends also provide a physical trap to collect some solids from being allowed through to the sewer system.
 
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Nov 11, 2009
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You can buy compact strain traps I had one on a van. Reich used to make them and others too. Looks like this

7B1BA67C-B183-44D9-8216-587DC71D0A9F.jpeg
 
Nov 16, 2015
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A "U" bend will not stop back flushing if water. The purpose of a "U" bend is provide an air lock to stop smells from waste pipe systems and sewers from emerging back into the living space. Some "U" bends also provide a physical trap to collect some solids from being allowed through to the sewer system.
I am with the Prof on this, fitting a U bend is compounding the problem. Fitting a smooth pipe and dropping the outlets on the side of the caravan will be more effective.
 
Jul 18, 2017
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You can buy compact strain traps I had one on a van. Reich used to make them and others too. Looks like this

View attachment 3931
Actually posted the link for the above, but for some reason it did not show in my post. the above is the one I would go with as it offers and excellent solution to smells and water coming back into the shower.
 
Nov 16, 2015
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You can buy compact strain traps I had one on a van. Reich used to make them and others too. Looks like this

View attachment 3931
I would find a drain trap like this being a problem in the winter, when the outside temperature overnight gets to below 0c and the water in the trap would freeze, I have a bottle of diluted antifreeze which at the end of a shower , I put a quick squirt down the shower drain.
 
Jul 18, 2017
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I would find a drain trap like this being a problem in the winter, when the outside temperature overnight gets to below 0c and the water in the trap would freeze, I have a bottle of diluted antifreeze which at the end of a shower , I put a quick squirt down the shower drain.
Highly unlikely it would freeze even if the snow around the caravan was a foot deep. Air is trapped under the caravan and the "warm" air rises.
 
Nov 11, 2009
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I would find a drain trap like this being a problem in the winter, when the outside temperature overnight gets to below 0c and the water in the trap would freeze, I have a bottle of diluted antifreeze which at the end of a shower , I put a quick squirt down the shower drain.
I never had any problems with it from freezing. Although to be honest unless they were obvious I would not have know. I did similar to you in winter but used a car screen wash solution rather than antifreeze in the water system, , toilet flush tank and drains.
 
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