Here’s a few tips on installing a rainwater tank. I’ve tried to put down some of the most important parts of installing a tank in a brief easy to understand way. Please note, go to the installation guide on our website for our complete guide.  
 

Preparing the base 

The most important area of installing a rainwater tank is how you prepare the base. The most optimum is a concrete base, but the below points are a cost-effective alternative that is probably the most popular way of setting up rainwater tanks. 

Plumbing off the overflow 

Too many times, someone will install a tank and either not install the overflow at all or leave it unplumbed. The issue with this is that when the tank fills up and overflows, the water rushers out the overflow or manhole and begins to wash away your base, potentially causing the tank to tilt over which is quite critical for the structural integrity of the tank and can void the warranty.  

So even if you are not plumbing the overflow into a stormwater drain, I always recommend running an elbow off the overflow fitting, run a pipe down to the ground, have an elbow on the ground with a pipe from that running along the ground away from the tank.  

What goes in must come out 

In simple terms, what volume goes into a rainwater tank must be able to get out the overflow just as quick. For example if 2 x 90mm overflow pipes are going into a tank through the strainer, you need 2 x 90mm overflows going out. In saying this if you have 2 pipes coming from off either side of a small shed into one tank, the 1 x 90mm overflow could be enough as there is not as much volume going in. If you’d like further help on your specific requirements please give us a call and we’ll talk you through it.  

Planning your outlets 

The difference in a Rapid Plas rainwater tank is that they come with 2 x 1 ½" outlets fitted as standard at 3 o’clock and 9 o’clock. This is when you’re looking down from the top with the strainer at 12 o’clock. 

My simple tip here is that you get an extra ball-valve and install it on the 2nd fitting that you might not be using now. The reason for this is that if you ever want to use that outlet down the track you can just plumb off the ball valve with it in the off position. Of course, if you don’t, and you ever want to use that fitting, the tank must be empty which can be very inconvenient.  

For any questions or just to double check for your own peace of mind feel free to reach out, we’d love to help you get prepared. 

Written by Roy Firth