Collecting rain water from the roof of your motorhome

For those who have never lived in a motorhome or caravan for an extended length of time, this must seem like a strange thing to do – why would you bother?

Well, like many full-time travellers, we like to spend time away from towns and people. In fact we just love to park up in a remote bush camp or on a deserted beach for weeks at a time.
Without exception, water is our greatest limiting resource. We make power from the sun, we can carry food to allow us to feed ourselves for months at a time, but we can only carry enough water for about 3 weeks. After about 3 weeks, we need to go and find water and re-fill the tanks.
Can you imagine how distressing it is to be standing under the awning during a rain storm and watch all that fresh water hit the ground when our tanks are almost empty?

Rain water guttering

The guttering

We have in the past rigged up a system to capture water from the awning – this however takes time to setup and sometimes the shower is over before we get it working. This is why we decided to install a permanent solution.

The solution needed to be both cheap and simple to install. For that reason we decided to use plastic extrusion – the kind you can find in most hardware stores. I first looked at using aluminium – however, this is quite expensive and is difficult to twist (twisting is required due to the curved edges of the roof). Plastic breaks down when exposed to UV – we therefore knew that the plastic guttering would need to be painted.

Because we do not always park the bus on level ground, we needed to put the guttering on quite an angle to make sure that the water would always run towards the back of the bus, into the collection funnels and down the hose towards the tanks.


The collection funnel
The collection funnel

The alternative to this large (and not so pretty) slope on the guttering is to place collection points at both ends of the guttering. For us it was difficult to get pipes down from the front of the bus so we decided only to collect water from the back.

The collected water flows from the funnels (that have a mesh cover to stop twigs and leaves) via some very cheap half inch garden hose to a series of valves. One valve (the dump valve) can be operated from inside the bus. In the normal position, water from the roof passes through this valve and is dumped onto the ground. This allows the first few minutes of rain to clean the roof. Once this valve is closed, the water flows via a course filter into the main water tank. It is also possible to direct the water into the drinking water tank.

So does it work?
Yes the system works well. We have had a few days of rain and each time we have filled the tank to capacity.

Comments. If I was doing this again there are a few changes I would make.

1. I would try to collect the water at both ends of the guttering – the slanted guttering really does look ugly.
2. I would use much larger hose to bring the water to the tanks. The half inch garden hose is quickly overwhelmed in heavy rain.

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6 Responses to “Collecting rain water from the roof of your motorhome”

  1. john/cindy Says:

    Hi there hope your well.
    I am soon 6months quiting work as a boilermaker and buying a bus and heading north for however long we feel,just wondering if you get a chance there is a bus bedford bus on ebay for $8500.00 would you have a quik look at it and let me Know wot u think.
    with thanks.

  2. Hobo Says:

    Hard to tell from the description/photos. A few comments…
    The bedford 466 is a good engine – but very old (1950’s)
    Mid mount engines are a pain due to the need to have access to the floor above them and they also hang very low causing issues with ground clearance.
    Being a town bus, it has no outside locker space.
    Please read my artical on build or buy – I always recommend you look at motorhomes already converted and carefully consider the cost and time involved in doing a conversion.
    Hope this helps

  3. Glen Swatman Says:

    As full time travellers we also findthat water is the first thing we run out of. In a simplistic form we have collected large amounts of rainwater simply by allowing the motorhome to slope and then catching it in a bucket from the awning. Your method is a great improvement on this concept and we will be considering it for our next motorhome. When you say you can last 3 weeks without a water supply how much do you carry or how much a day do you average?

  4. Glen Swatman Says:

    P.S. If anyone is interested in suggestions for reducing the amount of water you use in a motorhome then I have a blog posting on this topic.

  5. Hobo Says:

    It largely depends on quite a few things. If we have access to salty bore water, the main issues is drinking water and our 200 ltr tank lasts us about 3 – 4 weeks.
    If it is very hot we use less water because the showers are always in cold water and there is less water wasted waiting for the correct temperature.
    So we carry 200ltr of drinking water (filtered in and out of the tank) and about 300ltrs of fresh water (filtered into the tank).
    We have a remote control for the water collection system inside the motorhome. This allows us to dump the first 5 minutes of water from the roof (to clean it) then close a valve to allow the water to flow through the course filter and into the water tanks (either or both tanks).

  6. Milton Watkins Says:

    Thanks for the idea, we will def be using this way, we have a 18m Bendy Bus that we are converting, so 43sqm of roof space wasting water and flooding front and rear of our bus when it pours, so will be rigging up a number of tanks, funnels and shaping the channel was what I was trying to figure out, so thanks for your great website and ideas.

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