PVC trunking for outdoor use?

Can you please advise whether PVC trunking is acceptable for outdoor use? I plan to install a short section through a wooden conservatory window frame to carry the 5v DC power supply for a CCTV camera, but I'm aware that PVC used to degrade in sunlight. Hopefully these days it's UV resistant? The stuff I'm planning on getting is this https://www.wickes.co.uk/Wickes-Round-Conduit---Black-20mm-x-2m/p/109639 and associated elbows, but it doesn't mention outdoor use, though 'sheds' suggests is should be okay.

abenn said:

... I'm aware that PVC used to degrade in sunlight. Hopefully these days it's UV resistant?

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One can get PVC which has various degrees of UV-resistance, but I rather doubt that such materials would be used for trunking, which is very rarely used outdoors.

You can protect it from UV by painting. Furthermore, the effect of UV will be to discolour it and maybe make it go brittle, but even that is likely to take a number of years, so I'm not sure that it's really much to worry about (even if not painted), particularly give that it's just a short length carrying 5V.

Kind Regards, John

Trunking is different to conduit.
Seems you mean conduit so…
If you run long lengths outside, then use slip couplers or the run can either bend or become disconnected as it warms/cools.

Duplicate

Looks like they haven’t fixed the problem with the echo!

Thanks for the replies. Yes, I should have said 'conduit'.

Incidentally, I believe that certain paints can degrade PVC. I won't need to use if for my limited run, but just out of interest is there a paint specifically designed to protect PVC from UV? I know in the construction industry we could get UV-resistant PVC pipes. It's a long while since I retired, so maybe all PVC is UV resistant these days.

Also, it won't apply to my limited run, but thanks for the advice on slip couplers -- makes sense.

abenn said:

Incidentally, I believe that certain paints can degrade PVC. I won't need to use if for my limited run, but just out of interest is there a paint specifically designed to protect PVC from UV?

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There are certainly some solvents that can damage/degrade PVC but, in practice, I've never heard of any common type of paint causing any problems. I've certainly, in my time painted PVC with a wide range of emulsion paint, from oil-based gloss and cellulose-based to water-based emulsions etc. without any problems.

The real problem is that PVC is difficult to paint, because paint doesn't adhere very well. However, with all the types of paint I've tried (as above), one can usually succeed with a few coats.

There are certainly paints specially designed for PVC, but I think they seek mainly to address the adhesion issue. I imagine that the pigments in almost any paint would act as a reasonable block to UV, but I don't know for sure.

abenn said:

I know in the construction industry we could get UV-resistant PVC pipes. It's a long while since I retired, so maybe all PVC is UV resistant these days.

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As I said/implied before, there is certainly still plenty of PVC around that is not UV-resistant (for a start, the PVC sheathing of electrical cables). I'm not sure whether 'rigid PVC' (as in pipes and construction materials) is any more likley to be found in a non-PVC-resistant form that 'flexible/soft' PVC (as in el;ectrical cable insulation and shdeathing).

Kind Regards, John

After all that ....blah blah ....it will be fine

sparkymarka said:

After all that ....blah blah ....it will be fine

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Indeed - as I wrote in the very first response ...

JohnW2 said:

You can protect it from UV by painting. Furthermore, the effect of UV will be to discolour it and maybe make it go brittle, but even that is likely to take a number of years, so I'm not sure that it's really much to worry about (even if not painted), particularly give that it's just a short length carrying 5V.

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... and then, in response to the OP's follow-up question ...

JohnW2 said:

There are certainly some solvents that can damage/degrade PVC but, in practice, I've never heard of any common type of paint causing any problems. I've certainly, in my time painted PVC with a wide range of emulsion paint, from oil-based gloss and cellulose-based to water-based emulsions etc. without any problems.

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