Water drainage from shower and sinks

[Grey13]

Hi, I will change the piping under the van to improve waste water flow. Currently when I shower water does not drain away fast enough and I end up standing in a pool of water. My pipes are routed under the van and exit on the side, then I need a flexible hose to take it to the grey water on site drain. That includes unnecessary length and bends all of which restrict flow. Even if there is no drain and I must use a grey water container, the routing for the shower runs from the far back RHS where the shower is to the opposite side middle of the van. May I add, although there is ample room for gradient, the pipes are just attached hard up against the underside of the van. I will probably start by routing the exits to the back of the van, which means the shower drain in my shower is no more than 400mm from the back edge of the van. I will still route it across the width of the van to get it to the back LHS where if you are on a site with grey water facilities they usually situate the drains. I will also ensure there is a GOOD GRADIENT on that pipe. Currently my van has a factory swift discharge fitting that requires flexible hose which also adds a flow restriction. I will use a straight 1 1/4 grey PVC pipe to which I will connect my external piping. My question is, does anyone else have their grey water sink and shower discharge fittings at the back and not the side? Any other constructive comments? Grey

 

[Dodger524]

Some vans do have the waste outlets at the rear but wherever the out let is the flow will be slow. Look on the bright side if you are standing in water at least your feet get a good wash.

 

[Hutch]

I have thought of your idea in our last three caravans as well as insulating the drain pipes to stop them from freezing up. Although I have insulated the waste pipes i carry a small water plunger so that as the water waste flow slows down a quick plunge and the water clears enough for another week or two.

 

[VicMallows]

My waste outlets are both at the rear. The biggest problem arises when pitched on a slope so that the rear is very close to the ground. I have a project on the 'to do sometime' list ...... to make a shallow sump (about 10l capacity) into which the drains will flow freely. An automatic bilge pump will then pump the waste water easily into either a drain; a hedge where appropriate; or a dedicated aqua-roll. (The later because far easier to roll to the emptying point than the horribly balanced WasteMaster).
My experience on boats tells me that even the smallest bilge pumps will more than cope with the required volume at the discharge-pipe lengths and head required, using 22mm ID hose.

 

[Dodger524]

There have been discussions on sump pumps in the past and this product was discussed.

 

[woodsieboy]

In reply to the OP regarding connecting to site drain, we use about a foot of flexible pipe connected to caravan, after that white rigid piping, domestic type from B&Q, kept off the ground, with a slope to the drain, we carry various lengths and connectors so we can adapt to wherever the drain is, and never get a problem with water draining slowly

 

[audiorob]

I can see the logic of routing the outlet straight to the rear, shortening the pipe length and avoiding loops through the chassis members. Our first two vans had rear outlets, current van they are together towards the rear o/s. I think this is common practice as already suggested there is more likely to be drop into the waste container at the side than the rear if the pitch is sloping. Out of interest you might like to look at advice on domestic pipe runs, a min of 1/4 inch per foot length is advised (doityourself.com - Drain pipe slope calculator)!
Good luck with your project!

 

[Rod_5079699]

we also use a short length of flexible pipe from the van then 32mm domestic purchased from B&Q never any problem like we had when just using a long length of flexy

 

[Raywood]

We did have an Eldiss where the water was drained out the back, but whenever we pitched facing down a slope we had problems getting the waste water into the container as it could have to go up rather than down. The water drains best when the outlet is near the axle so that any slope is less of a problem.
If like us your shower is on the nearside and the outlet on the offside, drainage can be a problem although ours is not too bad. I can only think that moving the outlet to the nearside will help unless you have an outlet with a too narrow drain pipe in which case you might be able to fit a bigger one. An outlet on the nearside will interfere with any awning and could be a nuisance though.

 

[KeefySher]

Sure I've posted this before, but this makes an elegant solution to grey water drainage:

https://caravanchronicles.com/2013/05/26/connecting-your-drainage-on-serviced-pitches/
The key to drainage is the correct fixing of the pipes underneath the caravan floor, which in our case on a flagship top of the range caravan wasn't thrown together correctly at the circus. The dealer soon put things right and actually fixed the pipe clips in place to give correct flow.

It ain't rocket science.

 

[Grey13]

Hi. After much research and advice from posts here I have come to the conclusion that the poor drainage is caused by poor pipe routing necessitating extra length and other restrictions all hindering the waste water flow. Here are two pictures showing the under van piping
http://www.qis-uk.co.uk/Pics/Under%20Van%201%20.jpg
http://www.qis-uk.co.uk/Pics/Under%20van%202%20.jpg
Apart from the gradients being all wrong, having numerous restrictions each time a 28mm flexible hose connects to the PVC 1" pipes and other problems I still need to run MORE flexible tube from the side exit to the site service point. All this means I end up standing in a few inches of water when I shower.
Watch this space:
I will now strip all that out and replace it using 1 1/4 pipe and modified connections that do not restrict flow at all. My shower outlet will run from the point where it exits the floor less that 1 meter and out the back either straight into my waste water container or into the site waste water drain. You will not get a shorter route!.. Secondly I will modify the shower tray waste fitting shown here so that it has much less flow restriction by removing every second spar, allowing max flow from the shower tray.
http://www.qis-uk.co.uk/Pics/Shower%20Waste%20Drain.JPG
I will post pictures and a report on how well it works once completed!

 

[otherclive]

Yes that is a layout that would drain slowly and because of the slow draining would be susceptible to blockage too. I wouldn’t modify the shower drain fitting as with your plans for better routing and smooth pipe it should drain satisfactorily as it’s little different to a domestic installation but with a much shorter run. Our shower is offside straight to a side outlet just aft of the axle and I can pour a bucket of water down it and it drains rapidly.

 

[Grey13]

OK Good Peeps! Plumbing finished. http://www.qis-uk.co.uk/Pics/Van%20plumb%2020171118%20-2.jpg Took the hosepipe into shower and there was absolutely no backup, free flowing perfect. BTW both sinks worked perfectly with fast drainage. Job done! In case you forgot what it looked like before http://www.qis-uk.co.uk/Pics/Under%20Van%201%20.jpg

 

[woodsieboy]

Looks good, nice neat job and pleased to hear it works well, ours drains to rear already but think I will go with the larger rigid pipe as well

 

[otherclive]

A nice job, pity the makers cannot do something similar isn't it?

 

[Harby]

We've struggled with drainage from the shower, especially as our daughters and I will only shower in the caravan, not the toilet blocks...
Our shower is at the back, door side, and the drainage point is near the axle. We've had various versions of the flexible pipe, including routing it through rigid pipe (M. Bricolage's finest plumbing pipe) to keep it stable (found that awning-peg-tripod contraptions never held the weight of the water - all that Girl Guiding bedding rack work just didn't work out in real life situations!) and now have a little bag of lots of bits of pipe and connectors so that we can always reach the drainage point, however hard the campsite makes it!
If all else fails though, I send Mr H to empty the waste master before and after our showers then all the drainage problems seem to go way

 

[Hutch]

Nice job Grey, another year until warranty expires and then transfer my fantastic Coachman.
Hutch.