Concrete filled PVC pipe for pier

[namloc]

Hi guys, I am in the early stages of planning a permanent mounting for the scope. The pier will be of the "concrete filled PVC pipe" variety. I just have a concern over the pipe. What are the chances of the PVC pipe splitting or cracking from the contraction/expansion of the concrete inside it over time?

[JKB]

No expert but I would guess pretty rare. The type of pipe you choose would make a difference. Underground waste pipe has a huge amount of pressure applied to it with freezing/thawing ground etc so should be no worries.

Mines made of it

[pritc]

160mm underground waste pipe is the way to go!!

Used by several obs self builds from this forum,including myself

Wayne

[Earl]

I have a length of pipe i cant give away !

[spaceboy]

The UPVC underground pipe will not rupture. I concreted my rods into a 150mm pier only to find they were wrong DUH!! Grinding them of I had to go with rawl bolts which basically expand and grip there surroundings. I did them tight enough that the concrete and pipe are both bowing slightly but has been perfectly fine that way for 6 years and counting.

[Coco]

Make sure it at least 150mm!

Give you an idea of how flexible concrete is just grab the top of a fencing panel post and push pull on it, knock it with the sole of your hand and feel it ... it'll vibrate like mad..

150mm is entry level for a lightweight EQ and small scope if your imaging..

[malc-c]

160mm underground waste pipe is the way to go!!

Used by several obs self builds from this forum,including myself

Wayne

Agree 100%

[Digz]

Would the pipe cracking be an issue? Sure during curing it would be a pain but once the concrete has set the pipe isn't really doing anything other than looking like a pipe.

As others have said above I would certainly make sure you use at least a 150mm diameter pipe.

[malc-c]

Look at some of the examples here.

Using 160mm diameter pipe works, and when painted don't look like a simple pipe...

There are some examples of large diameter stainless steel air con pipes that also look really cool, so unless you leave them un-painted, the only give-away that it's a drain pipe is the orange colour

[Gina]

Would the pipe cracking be an issue? Sure during curing it would be a pain but once the concrete has set the pipe isn't really doing anything other than looking like a pipe.

Concrete shrinks slightly as it cures so the pipe will be slightly loose. So it won't be doing anything other than looking pretty.

[JamesF]

Underground pipe generally isn't UV-stable, so it's probably not a good plan to use it anywhere it might spend a lot of time in daylight, especially bright sunlight. I'd not use it for an outdoor pier, for example, unless you can handle it discolouring and cracking over a period of a few years.

James

[Gina]

While I was sorting things out, my plant pots discoloured quite a lot. They'd been out in the light. They were the same colour as terracotta colour u/g pipe.