How to Build a Rainwater Catchment On a Shed Roof. It’s easy to attach gutters onto your shed roof to collect water for your vegetable garden.
We decided we were going to add a few rain barrels on the land to collect water for the garden. We are trying to be “off the grid” as much as possible for this adventure so it made sense to us to try to catch all the free water we could. For this, we built a shed in the garden and added gutters to it to collect water into the rain barrels.
In just a few days we collected a full 50 gallons of water into one barrel, so it was a big success! Now we hope that it rains every week so we can get a full 100 gallons to water our plants with. Here’s a rain barrel calculator if you want to see how much rain you can collect.
How to Build a Rainwater Collection System
Here’s how we did it:
First, we built a shed This is the 7×7 Rubbermaid Roughneck Gable Storage Shed that we got from Lowe’s to place into the the garden. It was easy to put together as you can see in our time-lapse video.
We bought cheap vinyl gutters and mounted them to our shed with gutter mounts. The most difficult part was the mounting of the gutter hangers. For this we used machine screws to install the gutter hangers on the shed by drilling through the shed wall and fastening the machine screws with washers and a nut.
We used a gutter end with a drop at the back of the shed to funnel the water down and then some flex spout to direct the water right into the rain barrels. The rain barrels are connected to each other in the back with a small hose that we cut. Once one barrel fills up, then the hose will transfer water to the 2nd barrel until they are both full.
Here you can see the shed with the gutters from the front:
Gutter on the right side:
Gutters from the back:
Gutter from the left:
Gutter going into the rain barrel:
Water success! We attached 2 screws into the gutter that go into the rain barrel, this holds it into place.
The back of the rain barrels are connected. When one gets filled, then the water transfers to the other one.
Once filled water, you can put the water into a watering can..
Or set up a generator/hose sprayer and water the garden.
Enjoy the water plants! This baby broccoli sure is.
Jordan Hadawar says
This is really great – have you ever had an issue with rodents getting into the water barrels?
Pamela Reed says
Hey Jordan, we haven’t had an issue but we have a plastic mesh that goes over the hole on the top of the barrel that keeps most things out. You could do something with plastic or metal and secure any holes. Hope this helps!
Michael says
Is the shed material conducive to filter in this water later for drinking?
Damian McCue says
Hello, this is a great tutorial. Thank you for the info. I noticed your links to Lowes aren’t working. They just go to the Lowes homepage. Do you happen to have the names of the items you used (gutters, hangers, etc) so that I can look them up?
Thank you
Suzanne says
The material of the catchment container is important. You may be putting toxic plastics into your food. That’s the problem with trash cans or anything that is not food grade.
Rob says
How many square feet or meters is your roof and how much water do you collect from, say, agoo 20 minute thunderstorm? I mean, how hard is it to fill those two barrels? If it’s a hot day and you get an afternoon thunderstorm, do you have enough rain for the next day?
Pamela says
Hey Rob, here is a calculator which might help you: http://www.gardeners.com/how-to/rain-barrel-how-to/5497.html?SC=XNET9454. It also has some good examples on the page for square footage.
Elvis M. Ives says
I really liked the video and this seems very easy, um gonna try this for my garden. This is really inspiring. Thanks for sharing the post.
Bret Walburg says
Putting in a backyard shed/office and looking to do the same! Nothing beats rainwater for the garden, and great for back-up water supply for emergency preparedness.
Wondering – when the second barrel is flow, how are you handling the excess water from the 2nd barrel?
Thanks!!
Pamela says
Hey Bret, I totally agree and this works great. Right now we have 2 full rain barrels ready to go! When our second barrel is filled, it pretty much just overflows. If you want to keep the system going though… keep adding more barrels!
Holly says
How do you keep the water clean and not allow mosquitos or algae to grow?
Pamela says
Hey Holly, these specific barrels don’t attract algae or mosquitoes because they are covered. The water is naturally clean, it’s rain water. If you are using something else (such as a big trash can) you can cover the top of it with a screen netting. Algae grows due to light, so you want to eliminate as much light as possible. If you are using a trash can, then you can attach a rain gutter directly into the rain barrel and put a lid on top to eliminate the light. Hope this helps.
Susan says
Wow that shed went up fast 😉 With a garden the size of yours the rainwater barrels are a wonderful idea!
Dannii @ Hungry Healthy Happy says
what a great idea, and it just shows that you don’t need a lot of space either.
Pamela says
Totally, it’s really amazing how much water you can collect in a small area.
handmade by amalia says
You two are getting a lot done!
Amalia
xo
Pamela says
Lots of work, but totally worth it seeing it all come together!
Karen (Back Road Journal) says
You two are something else. I’ve always admired your rooftop garden adventures but this garden is a true labor of love for you both. I’m really enjoying each of your posts to see what you next accomplishment has been. Just terrific!
Pamela says
Thanks Karen, I really appreciate it! It’s been lots of fun building and just doing whatever we can dream of (no rules!). The rooftop garden has a special place in my heart, but so does this new adventure.
Suzanne says
Great source of water. Here’s hoping for a good amount of rainfall so that you will have enough water for the entire season. Looks great.
Pamela says
Thanks Suzanne! It rained over a inch this past weekend so we had close to 400 gallons with a few barrels filled!