Shower drain

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Feb 13, 2022
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Thanks for all the replies everyone. I’ve had a very productive afternoon. I’ve got a new PVC pipe fitted. I would have had to extend the sink pipe to make it go onto the splitter with the kitchen sink, and would have been difficult to maintain a decent flow. I discovered that it improved the flow from the kitchen sink with the t piece out the way and going direct to the outlet. There was a load of mucky water sat in there when I opened it. I’m have therefore gone with the three outlet plan. Dug out some more hair 🤮, blocked the trap and put drain cleaner in for an hour.

Basic pipework now in place and the flow from the shower plug hole is excellent. Straight down, gushing out the new pipe.

New outlet arriving next week. Not sure if pipe will marry up properly, I may need to put a short piece of flexi at the end.

Pictures will follow when I get home.
 
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Nov 16, 2015
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Your talking total rubbish BM. As soon as the OAT hits Oc the water frezzes.
 
Feb 13, 2022
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Been wondering how I would go from this pipe to a flexi and it looks a bit complicated due to the fact I am effectively trying to marry up two piping systems. With the rubber joining grommet from the convoluted hose placed over the end of the white plastic pipe, it fits nice and snugly into the caravan outlet, I tried it with one of the existing ones. I think potentially I need to put an extra pair of blocks on the bracket behind the elbow, and shorten the main run of pipe slightly to bring it more "square" with the back of the new outlet. I took audiorob's advice and used push fit instead of solvent weld, glad I did!

Jobs like this are frustrating! The storage site closes at 6pm so no time to go after work. Which means I'll be obsesssively pondering it all week! Then I'll get there at the weekend and discover I need a part which I can only order online. :rolleyes: Invariably the way with these jobs I do on my van.
 
Jul 18, 2017
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Your talking total rubbish BM. As soon as the OAT hits Oc the water frezzes.
Please do not say that I am talking rubbish when obviously you have never used a caravan in the middle of winter. We could argue the point, but you would lose as highly unlikely for it to freeze. Below is our friend's caravan who had the device fitted and no issues.Redstone Park04 Feb 2007.JPG
 

Sam Vimes

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Sep 7, 2020
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Please accept that experiences will vary and lets keep these conversations on a friendly level.
 
Jul 18, 2017
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I am trying however I will clarify. Our caravan had an underslung onboard tank and it never froze even during some of the severe winters. The reasoning was that the caravan has a skirt around it trapping the air underneath and this air would be warmer than the outside air.

In addition the ground underneath the caravan gives off heat even when the temperature is zero hence why some places have ground source heating. There is also some heat from the caravan when occupied however even when not occupied there will still be some residual heat anyway.

Unless a U tube(trap) or similar is almost touching the ground, it should not freeze. The kitchen basin one can be fitted inside the caravan. Same with wash basin however shower could be the issue as that would be the only one where the trap may need to be fitted outside under the caravan.
 
Mar 14, 2005
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A U bend does not stop water back flushing. provided its has water in the trap it will stop smells but it will not stop water reverse flowing.

As for freezing, any pipework exposed under a caravan when the air temperature is below freezing is perfectly capable of freezing. I it has happened to me, and I have seen plenty of cases where that has happened to others and caused damage.

Horizontal corrugated waste pipes will often retain small amounts of water in the corrugations. Because these are only small amounts it freezes quite readily when the air temperature fall below freezing.

Smooth bore pipes provided they have enough fall are more likely to drain completely, and if there's no retained water it can't freeze, but if the pipes are inadequately supported so they sag and create puddles or exposed u bends then if they are exposed for long enough to freezing air there is every chance they will freeze.

Not everyone uses caravan skirts, and even when they do they are not any guarantee of preventing air under the floor falling below freezing.

I have a condensing boiler at home, it has a condensate drain which was installed with a 40 degree sloping external pipe to take it to a drain. During a number of freezing weather periods, even the slightly warmed condensate could not complete the journey to the drain and the has pipe blocked.
 
May 11, 2021
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Isn't the smell-prevention aspect of a U-bend rather irrelevant since the piping is not plumbed directly to a drain but usually hangs in a Wastemaster or over a grey waste drain? I guess you could get some smells back but far less likely than in a domestic waste system that has a gas-tight connection to a foul drainage system.

Which kind of makes a U-bend a bit unnecessary...?
 
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Mar 14, 2005
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Isn't the smell-prevention aspect of a U-bend rather irrelevant since the piping is not plumbed directly to a drain but usually hangs in a Wastemaster or over a grey waste drain? I guess you could get some smells back but far less likely than in a domestic waste system that has a gas-tight connection to a foul drainage system.

Which kind of makes a U-bend a bit unnecessary...?
Essentially yes, But in a caravan it might help prevent a cold draught, or a smell from a waste container. It might also catch any earings that might be accidentally dropped down the plug hole. and of course it will stop insects or small mammals from getting in.
 
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Nov 16, 2015
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Please do not say that I am talking rubbish when obviously you have never used a caravan in the middle of winter. We could argue the point, but you would lose as highly unlikely for it to freeze. Below is our friend's caravan who had the device fitted and no issues.View attachment 3940
What makes you so sure I have never caravanned in the winter.
 
Feb 13, 2022
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Went to storage and finished job today. Used a flexi sink trap section to do the last bit to the outlet in order to get the correct angle on the outlet. Stuck the pipe onto the outlet with Soudall Fixall.

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Just gotta replace one of the original outlets as the lid has begun to tear off at the "hinge". Bit of a poor design, just a thin bit of plastic.
 
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Jan 19, 2002
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As you know I have given up on the flaps on the outlets as built in obsolescence and now use two circular bungs made for the job bought off eBay for 3.75 pair.
One question for you - looking at your final 3 into 1 outlet wouldn’t it be better if the centre one faced left towards the drainage point as currently the water pressure from this is tending to backflow into the right hand outlet?
 
Nov 16, 2015
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As you know I have given up on the flaps on the outlets as built in obsolescence and now use two circular bungs made for the job bought off eBay for 3.75 pair.
One question for you - looking at your final 3 into 1 outlet wouldn’t it be better if the centre one faced left towards the drainage point as currently the water pressure from this is tending to backflow into the right hand outlet?
Didn't Beachball have the same problem when he converted to the three pipe outlet.?
 
Mar 14, 2005
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As you know I have given up on the flaps on the outlets as built in obsolescence and now use two circular bungs made for the job bought off eBay for 3.75 pair.
One question for you - looking at your final 3 into 1 outlet wouldn’t it be better if the centre one faced left towards the drainage point as currently the water pressure from this is tending to backflow into the right hand outlet?
It is certainly good practice to try and follow the desired flow path, but in this case a doubt whether the actual water flow from any of the fittings would have enough volume or kinetic energy to cause a back flow problem. Of course if the final out let was constricted, then the standing water in the pipes might back up.
 
Feb 13, 2022
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I’ll try reconfiguring the position of the pipes next time I go to the van. I’m not sure though whether this will prevent the hoses lining up well enough. Both the sinks are piped more or less straight down so not much chance of back wash.
 
Nov 11, 2009
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I’ll try reconfiguring the position of the pipes next time I go to the van. I’m not sure though whether this will prevent the hoses lining up well enough. Both the sinks are piped more or less straight down so not much chance of back wash.
It would look so much more professional if they were aligned, and if you could remove the sticker on the middle outlet too it would then pass muster 🤣🤣🤣

Sorry that’s my OCD popping up again. Tongue firmly in cheek.
 
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Jan 3, 2012
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Went to storage and finished job today. Used a flexi sink trap section to do the last bit to the outlet in order to get the correct angle on the outlet. Stuck the pipe onto the outlet with Soudall Fixall.

View attachment 3962

View attachment 3963

View attachment 3964

View attachment 3965


Just gotta replace one of the original outlets as the lid has begun to tear off at the "hinge". Bit of a poor design, just a thin bit of plastic.
Exactly what my caravan look like after the same job(y)
 

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