Marley dropper outlet question... incorrect install?

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JayADee

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#245108 18-Jan-2019 20:14

Our young builders installed some Marley for us as part of a roofing job.

Problem is they used regular instead of expansion dropper outlets to the downpipes so there are no expansion joints on any of the four independent sections installed.

One length of spouting is more than 8 m, another is over 3, about 3.5m , another maybe ok at 2ish and the other section is again over 3, probably 3.5m.

Am I right that this is an incorrect install?

If so, what is the best way for them to fix it? Remove and replace with expansion droppers or would installing an expansion joint somewhere in the middle work?

Thanks for any advice.

J

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#2163434 18-Jan-2019 20:24

Don't you only need expansion joints after 12m? I certainly wouldn't be worried about those 3m runs

Jase2985

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#2163436 18-Jan-2019 20:35

nickb800: Don't you only need expansion joints after 12m? I certainly wouldn't be worried about those 3m runs

sounds about right

From the installers hand guide:

"NOTE: If an expansion outlet is not included in a straight run exceeding 12 metres, an expansion joiner must be fitted to accommodate thermal expansion/contraction"

JayADee

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#2163438 18-Jan-2019 20:40

Pretty sure runs over 12 m need an EXTRA expansion joint, in addition to expansion droppers.

Marley Trade install instructions:
https://www.marley.co.nz/wp-content/uploads/dlm_uploads/2016/04/Spouting-Downpipe-Trade-Installation-Guide-August-2016.pdf

See also parts list where non expansion droppers are specified as for 'very short runs' ie. less than 2m it says elsewhere: https://www.marley.co.nz/wp-content/uploads/2016/05/MAR2249-Marley-Quantifying-Pad.pdf

Expansion outlets specific trade installation guide:
https://www.marley.co.nz/wp-content/uploads/dlm_uploads/2016/07/Expansion-Outlet-Instructions.pdf

Homeowner type guide
https://www.marley.co.nz/knowledge-hub/diy-nation/spouting-systems-2/install-spouting/

JayADee

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#2163439 18-Jan-2019 20:42

The young fellas did our garage and shed.

On the house, done by another company, we have one side that is a very long run. It has an expansion dropper on both ends and an expansion join in the middle. All other droppers are expansion droppers.

Jase2985

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#2163447 18-Jan-2019 21:12

i dont know, its doesnt state that, and non of the links you provided say that bar the quote i pulled from the installer guide

the note seems to say one or the other for a run over 12m. as per my quote above

JayADee

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#2163448 18-Jan-2019 21:12

So now on another guide I read: In a run exceeding 10m an expansion outlet or expansion joiner must be used and remember do not solvent cement spouting into expansion outlet.

It does sound though like expansion droppers are the expected default and not plain droppers.

Any experts?

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JayADee

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#2163450 18-Jan-2019 21:19

Jase2985:
i dont know, its doesnt state that, and non of the links you provided say that bar the quote i pulled from the installer guide

the note seems to say one or the other for a run over 12m. as per my quote above

It's confusing. The guides certainly do imply expansion droppers are the go-to default. Ditto for Mitre10's DIY video.

My concern comes from having the original (when we moved in) spouting on the house leaking at the joins from having zero expansion joins/droppers according to a roofing co. I don't want the same thing happening to the garage, carport and shed.

Jase2985

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#2163451 18-Jan-2019 21:20

you can use either the joint of the dropper just depends on how you want to set it up.

JayADee

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#2163459 18-Jan-2019 21:47

So for less than 12 m no expansion join or expansion dropper is required?

wally22

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#2163472 18-Jan-2019 23:08

If you want to play it really safe, you could put an expansion joint in the middle of the 8m run, but it is probably not necessary.

It really depends where you are in NZ and your usual summer temperatures. Plastic expands. I would definitely put one on a 10m or longer run. You do not want it buckling in the heat as it is a pain to rectify afterwards.

JayADee

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#2163474 18-Jan-2019 23:23

Eastern Bay of Plenty.Thanks. Appreciate you people's advice. Sounds like it should be ok then. I'll just get a more accurate measure of the longest bit tomorrow and make sure it's under 10. The've done a really nice job on the roof etc. and it all looks very sharp.

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Bung

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#2163479 18-Jan-2019 23:42

Even with just a plain dropper through the bottom of your spouting there's probably enough give in your downpipes for the run to move. If you have ends of the spouting fixed into corners that are attached to the fascia then you'd have to allow for expansion.

eracode

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#2163498 19-Jan-2019 04:37

The coefficient of thermal expansion of Marley PVC-U is 0.05mm/metre/°C.

So an eight metre run coping with, say, a 25°C temperature variation, will produce a change of 10mm.

Sometimes I just sit and think. Other times I just sit.

nickb800

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#2163505 19-Jan-2019 07:22

On that long run, make sure there's a bit of room at each end for expansion (not hard against the barge board)

k1w1k1d

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#2163546 19-Jan-2019 08:29

Would it be possible to swap the droppers with expansion ones?

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