OFF GRID Rainwater Harvesting System – Part 2 – Fence Surround

Off-Grid Rainwater Harvesting Tank in the garden
Off-Grid Rainwater Harvesting Tank in the garden

The surround has five 4x4 posts that support 2x4 and 2x6 rails.

animation of tank surround
animation of tank surround

Jump to:

Off-Grid Rain Tank Part 1 – Pour the Tank Foundation
Off-Grid Rain Tank Part 2 – Build the Tank Surround
Off-Grid Rain Tank Part 3 – Tank Plumbing and Fittings
Off-Grid Rain Tank Part 4 – Install a Solar Powered Pump

Watch this video on YouTube.

See the Youtube Video Part 1 or Part 2 or Part 3 or Part 4

Off Grid Rainwater Harvesting System – PART 2: red cedar and corrugated metal fence surround

(this is a transcript from the video)

The posts are screwed to adjustable galvanized saddles. These lift the post up off the concrete by an inch.

animation of tank surround
animation of tank surround

The top and bottom rails on the sides of the surround have a rabbet cut in them. So I can flush mount the galvanized corrugated panels.

animation of panels attaching to tank surround
animation of panels attaching to tank surround

Around the back of the tank I created a space for a mini pump house. This will hold the solar controller, battery, fuses, etc for the DC water pump. This rainwater harvesting system will run completely off-grid.

OFF GRID Rainwater Tank - mini pump house behind the tank surround
OFF GRID Rainwater Tank – mini pump house behind the tank surround

Build the Water Tank Surround

We wanted the tank and surround to feel like an extension of the pavilion. So we adopted the timber frame look with full dimension rough sawn red cedar. And we used the same stain for the surround as well.

cutting cedar fence posts
cutting cedar fence posts

What I’m building here is beyond what is needed for a rainwater collection tank. But, we wanted to do something different and dress them up sorta speak. And for this particular tank the fence surround is also functional as it will support some of the plumbing and wiring later.

Our property is sloped and there’s not many truly flat and level spots. And in the winter with our heavy rains the soil can get soft and saturated. For those reasons we decided on pouring a concrete curb to hold the gravel and then this acted as a foundation for the fence surround.

We are blessed to have lumber milled from our own trees for many of these projects. When we poured the curb I embedded some anchor bolts to hold these post saddles.With the Sketchup model done I can start cutting the parts.

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I’ll cut all the 4x4’s first. Behind me there is the 1200 gallon tank that I covered in the first rainwater collection series.

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Next I’ll cut the 2x6’s for the bottom rails. And then the 2x4’s for some of the mid and top rails. I can get away with cutting everything to final size here as I was careful to set the forms and pour the curb square and level.

And then I cut a rabbet in the top and bottom side rails. A viewer in the previous series commented that I should have made the horizontal cut on a slight angle for water drainage. And that is totally true.

With all the parts done I roll on some stain. This is a one coat Sikkens semi-transparent stain. It dries overnight and , with only a single coat, the parts are not oily to handle and work with.

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I do add a few extra coats to the tops and bottoms of the posts and to the ends of the rails. And I was thinking that I’d like to add a low profile, simple, galvanized cap for the posts. If I can find or order some somewhere. Maybe I could just cut a square of galvanized sheet metal and epoxy it on. The hardware stores in my area don’t carry a post saddle for a full dimension 4x4 so I need to trim mine down to three and a half inches. I love this western red cedar whenever I pull out a chisel or need to shave it down.

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A single screw through the post saddle holds the bottom in place while I clamp a temporary brace to one side. Then plumb with a spirit level. Then I can repeat that on the second post. With the addition of another temporary brace.

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I use small blocks clamped to the post to support the rails. And a long pipe clamp pulls them together and holds them in place while I drill pilot holes then run in the screws.

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I’ll be toe screwing the rails into the posts. And I think this will do for this particular project.

Once I got a feel for how this was going together I drilled all my pilot holes in the rails ahead of time. And sometimes started the screws in the holes. This can make working solo a lot faster and easier.

Next I’ll add the middle rail. Again, blocks support the rail while I bring the posts together with a pipe clamp. And run in more and more 3″ screws.

A post is added to the East side, plumbed, and supports added. This side has two taller posts and a higher rail. I needed this additional height to support the 3″ pipe from the pavilion gutters and to support some of the plumbing setup.

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For the rest of the sides I’ll add rails starting at the bottom and work my way up the post. Then the mid rail followed by the rabbeted third rail. And a 2x6 at the top.

And around the West side all of this gets repeated.

At the back South facing side I’ll add three 2x6’s.

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We have consistent wind coming from the west so I though I’d add some additional protection for the pump house with this short section of fence.

I’ll jump ahead in time here to show the corrugated panels being added. Eighth inch spacers lift the panels to center them vertically. I used 1″ roofing screws that have a metal and rubber washer. I set my post spacing so I could overlap these a few corrugations and not have to cut them.

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Except for the last panel. I have an attachment for my drill that cuts sheet metal pretty well. But not as good as I hoped for these corrugated panels. It left a rough edge but I was able to straighten it somewhat with a hand seamer.

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Later I made some cuts with an angle grinder running against a straight edge that was clamped to the panel. And that worked much better.

Build the Mini Pump House

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The mini pump house will be a box with a sloped hinged lid. I made some walls with 2x3’s and 1x8’s. Then screwed these together. And I’ll add an exterior grade plywood bottom.

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And I can cut the end walls for the sloped top. I stained the box and added a top from plywood and attached it with gate hinges.

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This plywood has a synthetic roofing felt tacked on then corrugated panels attached.

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We temporarily set this box in place to see how it fits. And that’s pretty much all the carpentry work done.

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So I hope you have enjoyed this post, and thank you so much for reading. If I make any further improvements or changes I’ll post them here.

And, while you are here, please hit the Support Link to help us make more projects and videos like this. We really appreciate anything you can do to help us out!

Jump to:

Off-Grid Rain Tank Part 1 – Pour the Tank Foundation
Off-Grid Rain Tank Part 2 – Build the Tank Surround
Off-Grid Rain Tank Part 3 – Tank Plumbing and Fittings
Off-Grid Rain Tank Part 4 – Install a Solar Powered Pump

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