10mm might not seem like a very large amount, but when it comes to clearing drains it can make a huge difference in the result.
For a very long time, 100mm PVC has been the standard diameter for both stormwater and sewer drains. But in the past 5 years or so, 90mm PVC has become much more popular. Believe it or not, this difference of just 10mm between the two sizes of drainpipes can lead to a number of complications if the drain gets blocked and needs clearing.
The first problem with 90mm drains is that a getting a camera or drain clearing equipment around a 90° bend in ANY sized drain is very tight in the first place. Should that drain then have two or three bends, getting equipment around all those bends becomes almost impossible if the drain is only 90mm in diameter. The second problem is that many 90mm drains are laid with a “T-junction” (or right angle) joint, rather than a junction that joins at a less severe 45° angle.
Putting a camera down a drain with a T-junction, means the camera can easily go either one way or the other through the joint, causing a great deal of confusion for the camera operator who as a result sometimes cannot tell which way he is looking.
90mm PVC drains are often made of recycled material, which makes them more susceptible to squashing, as they are less rigid than 100mm pipes.
You are most likely to find 90mm pipes in new houses built during the past five years or so where they have almost replaced 100mm drains. Unfortunately many 90mm stormwater drains are often not laid completely in compliance with regulations, and so they do have a tendency to develop problems with blockages more easily.
So if your drains are 90mm in diameter, please understand that they may take longer to clear than regular drains and that in some cases we might not be able to get all the way through to the blockage.
We may therefore NOT be in and out in an hour, like we can often do with a lot of other drains.
Please let us know, if you know, that your drains are 90mm, before we come out to your place. It will help us manage both of our expectations better.
If you have any questions about pipeline inspections, drain clearing or pipe relining at your premises, or you are unsure whether your drains are 90mm or 100mm, please contact our friendly team. We’ll be happy to help in any way we can.