How close can deck post be to drain?

[NewSkil109]

I have positioned a deck support post fairly close to a drain pipe and I am concerned if I went too close.

The edge of the postcrete fill is roughly 240mm away from the pipe at the closest point, the post itself is at least 300mm+ away. The base of the post / postcrete is roughly the same depth as the bottom of the pipe.

I have drawn a full (to scale) image to show the situation, please can you take a look and see if you think this looks fine or if it would be best to move it. This is the main sewer line for the property heading down to the public drains some distance away.

Some photos:

 

[Ian H]

That will be fine.

 

[NewSkil109]

Thanks Ian, I already removed the post as I mentioned the question to our structural engineer in passing (he's working on another job) and he gave general advice of 'at least a 500mm gap' (same as water companies want from a house extension to main sewer, so I think a bit OTT for a deck but anyway...).

I'm going to reinstall it slightly further out (400mm-500mm) but deeper post hole to ensure load is well below the drain pipe, and obviously ground is a bit soft from all this carry on, so have to go deeper to hit hard dirt.

All a bit unnecessary, I am sure the original would have been fine as you said too, but there we go, it will be all sorted tomorrow.