How to replace downpipe?

corky55

I want to get this downpipe on right hand side of this post so I can put up a wall-mounted umbrella. Problem is the deck is already being cut around the downpipe at the bottom so I'm thinking I need to get it to turn around at the top and back again at the bottom. The pipes feel pretty stuck together so a few questions:

1. Is it possible to loosen the pipes? Would that be with WD40 or heat or would I likely need to cut it out?

2. Is the project worth trying to DIY or am I very likely to stuff this up?

3. I'd have to get new pipes cut to size - any tips on what pipe to get and what's the best way to cut them? I only have a hand saw at the moment.

Thanks!

MitchellMc

Hi @corky55,

You could physically re-route the downpipe around to the other side of the post, but it is not quite as simple as loosening what is already there.

Those downpipe joints are solvent-cemented, so they are not designed to be taken apart.

 

A plumber would use a combination of 90-degree elbows and short straight sections of matching downpipe to step it around the post, then bring it back down again. Once you introduce bends, you will almost always need extra pipe because the original vertical length will no longer be sufficient.

 

From a DIY point of view, the physical work itself is not especially difficult. PVC downpipe can be cut with a standard hand saw. You simply need to match the existing pipe size, most commonly 80 mm PVC downpipe, and use the correct solvent cement for assembly. However, altering a downpipe is classed as drainage work. This is work that should be carried out by a licensed plumber or drainer. In addition, plumbers are often reluctant to add multiple tight bends to a downpipe because each right-angle creates a potential blockage point, especially during heavy rain or if leaves are involved. What you are proposing would introduce at least two new areas where debris could collect and restrict flow.

 

It is also worth pausing on the umbrella itself. Posts that support a roof are designed for vertical roof loads, not for the large lateral loads an umbrella can generate in wind. A wall-mounted umbrella can place significant stress on a post, and that load can be far greater than people expect. You may want to consider whether the umbrella could be mounted elsewhere, such as to a wall, a dedicated post, or a freestanding base, rather than modifying both the drainage and a structural post.

 

Please let me know if you have any questions.

 

Mitchell