Making a concrete storm water drain

Build concrete storm water drains to move water away from your home.

Every time it rains, water comes rushing out of your home’s downpipes. This water has to go somewhere and over time it will cause damage if it isn’t channelled away correctly. Concrete storm water drains are just the thing to prevent this and they’re actually pretty easy to make yourself.

Plan first – properly! You want the drains to have a gradual downslope that moves water away from your house and doesn’t create pooling water. Use a piece of fishing line and a line-level to mark out where your drain should go.

Use a spade to dig a channel where the concrete will be. A width of two bricks and a depth of 100 mm is just right.

Cut strips of shutterboard to 100 mm wide and lay them on either side of the channel. You want the top of the shuttering to be level with the fishing line, so you may need to dig a bit further down to make sure the gradient is right. If the channel is going to be longer than your lengths of shutterboard, simply join other pieces to them using offcuts and screws.

Hammer in a few pieces of rebar on both sides of the shutterboard to keep it in place.

NOTE: If you are working close to a wall, line the wall with a piece of plastic to help to prevent damp in the walls.

Once the bed is fully covered, take a length of 110 mm PVC pipe and lay it firmly into the wet cement, where the drainage will to run. Work it into place and then place more concrete on each side of the pipe. Work the pipe into the concrete to get the concave shape you want.

Leave the concrete to dry slightly, then gently work the pipe out, giving it a turn as you lift it. When the pipe is removed, gently float the concrete to make it as smooth as possible.

Cover the concrete with plastic to slow down the drying time and leave it for at least a week. You can also give it a spray of water every few days to further slow down drying. When the concrete has cured, remove the shuttering. There you have it – a storm water drain that will prevent erosion and make sure your house isn’t damaged.