Summertime can be extremely tough on birds, especially in hotter climates. An easy way to help them out is to have some form of water for either drinking or bathing, in your yard.

In this Instructable I'll show you a cheap and easy way to bring the birds to your house, with a stylish and functional concrete bird bath.

You'll need:
- 90mm PVC pipe
- 90mm PVC push on cap
- A flexible tub, preferably made of silicone or rubber
- A flower pot tray
- 6mm Steel rod
- Adhesive
- Concrete

Step 1: Setup PVC Mold

Start by cutting your PVC pipe. Bear in mind that the length of pipe should be proportional to the size of the bowl. Ie, you can't have a 2 metre high, 90mm column for a bowl that's a meter wide because there is a good chance the whole thing will tip over. I don't want to bang on about safety but if you have children or energetic pets it would be better to use a wider pipe and cut it shorter.

I cut my PVC pipe to a meter long, intending to have 400mm below ground. Then, using an angle grinder with a diamond blade, cut a line all the way along one side. This will allow the pipe to be pried open after the concrete dries.

Once you've cut the pipe seal it again with some duct tape. It's also a good idea to wrap the entire pipe in tape because the weight of the concrete might cause it to split. I had to grab the tape midway through pouring the concrete, do yourself a favour and make sure the pipe stays closed!

In the PVC end cap drill a small hole just wide enough to accept the steel rod. I used 6mm galvanised rod cut to just shorter than the length of the PVC pipe. You want the steel rod to be centred through the concrete.

Step 2: Add Concrete to the Pipe

To give my concrete a darker colour I used oxide powder. This needs to be mixed into the concrete while dry. Personally I like to darken the concrete because it gives it a stone-like colour, which is more natural nestled in a garden. However, keeping it plain concrete would give it a more modern look.

Once all the concrete is mixed with water, start adding it into the pipe. The easiest way to do this is by hand. Use one hand to centre the steel rod, while the other adds concrete. Be prepared to get messy.

As you add concrete use a mallet or hammer to tap the pipe. This will help to compact the concrete by forcing any air bubbles to the surface.

Once it's filled set it aside to dry. Try to keep it as plumb as possible so the top of the column drys flat.

Step 3: Add Concrete to the Tub

Now add a layer of concrete, roughly 50mm, to the bottom of the tub. You can make this thicker but try not make it less than 50mm. We're not using any wire mesh or fibreglass, so the concrete needs enough mass to hold itself together.

Next, take the flower pot tray (I used a clear disposable tray) and give it a quick spray or wipe with some cooking oil. Then place it in the centre of the tub and add some concrete around the edges, between the tray and the tub. You want to aim for around 30mm+ worth of an edge so keep that in mind when purchasing the tub and tray. Keeping it that size allows the birds to sit comfortably and, again, making it too thin will just increase it's chance of cracking.

To keep the tray from rising place a heavy paint tin in the centre. This will keep it weighed down while it dries. And like with the pipe, vibrate the tub as much as possible to get those air bubbles out.

Step 4: Attach the Bowl to the Pipe

Wait 24 hours for the concrete to dry enough to manoeuvre it then start removing the moulds. The tub is flexible enough so giving it a light pull should stretch it enough to free the concrete.

Unwrap the tape from the pipe and, with it vertical, pop the cut open and slide the PVC pipe off. You might need to clean up the seam but ideally this side will face away from view in the garden.

Now drill a hole in the centre of the column and bowl, big enough to take a short piece of the rod. You only need around 20mm in each part. This is only to stop lateral movement. The bowl needs to sit flat on the column and be stable even without the steel pin.

Give the bowl a light sanding to round the edges and seal the inside of the bowl. You could seal the entire bird bath, but I want mine to weather more aggressively. Sealing the inside of the bowl is important though, because this will stop the water seeping into the concrete. If you don't seal the bowl you might get damp spots on the outside which won't look very appealing.

I used a water based concrete sealer because it dries relatively quickly.

Step 5: Install the Bird Bath in the Garden

At this stage the column and bowl are seperate. This makes installing the bird bath easier. I wouldn't recommend joining them until after you've got the column in the ground.

You could either concrete the column in place traditionally, placing the column in the ground then concreting around it. Or, what I did, was to create a concrete "brick" with a 90mm hole in the centre. I had left over concrete so I dumped it into a bucket and pushed a 90mm pipe into the centre. Either way would work.

Once the column is plumb use some form of adhesive (and the steel pin) to glue the bowl to it. I used a generic construction adhesive. Once you have the bowl in position fill it with water. This will give it more weight and help to "clamp" it in place while the glue dries.

And that's it. You're all set for summer and the birds will love you for it.