What size and type of rivets do I need to attach a 90mm plastic downpipe pop to a Colourbond gutter?

[Politenessman]

I'm planning on adding an extra downpipe to a standard domestic gutter, but I only want to do it once rather than have to come back and fix it later, so advice on the correct size and type of pop rivet would be appreciated.

Thanks.

[EricL]

Hello @Politenessman

Welcome to the Bunnings Workshop community. It's marvellous to have you join us, and thank you for sharing your question about attaching a plastic gutter pop to your Colorbond gutter.

In this particular scenario, I suggest using an Abey Australia 75mm Round Standard Downpipe Pops. Using plastic on a metal galvanized surface is not recommended as the plastic will tend to warp in the intense heat of the sun causing it to form leaks. If you're using a 90mm PVC downpipe the 75mm galvanized metal pop is the correct one to use. It provides an air gap between the pipe and the pop preventing an air-lock from forming and causing your gutter to overflow.   

Once you've cut the hole for the pop, I suggest using Selleys 310g Roof And Gutter Silicone Sealant - Translucent to join them together. You can then blind rivet it in place using Otter 3.2 x 3.2mm Open Aluminium Blind Rivets - 25 Pack. Please remember to leave a 10mm gap between the gutter and the downpipe to facilitate airflow.

If you have any other questions about your gutter, please don't hesitate to post them.

If you need further assistance, please let us know.

Eric

[DareDevil]

Hi Eric, 

Just curious as to how you attach a 90mm downpipe to a 75mm pop? 

[MitchellMc]

Welcome to the Bunnings Workshop community @DareDevil. It's fantastic to have you join us, and many thanks for your question about attaching a downpipe.

I think, in any case, it would be an 80mm downpipe to a 75mm pop, not a 90mm stormwater pipe. Regardless of whether it was an 80 or 90mm downpipe to a 75mm pop, I can only ever see one rivet being used. I suspect my colleague @EricL is aware of an issue with using the 80mm PVC pop in metal guttering and has suggested this approach as a compromise.

Were you planning on running 80 or 90mm downpipes?

Please let me know if you have any questions.

Mitchell
 

[DareDevil]

Hi Mitchell, 

I'm not planning to install a downpipe. 

I was just curious about connecting a 90mm downpipe to a 75mm pop.

Also, I had never heard before about a gap being required between a pop and a downpipe to prevent an air lock. 

I guess it makes sense. 

Thanks for your reply. 

[ChickenLittle]

Hi Eric, I noticed you recommended galvanised rivets for Colorbond however it appears bluescope recommend aluminium rivets?

Their website states "Where accessory fasteners such as pop rivets are required, they should be manufactured from aluminium when fastening Galvanized, ZINCALUME® steel, COLORBOND® steel, COLORBOND® Ultra steel and COLORBOND® Metallic steel."

Can I assume both are suitable? The last thing I want to do is cause rust on my new colorbond shed!

[JacobZ]

Hi @ChickenLittle,

Thank you for your question and welcome to the Bunnings Workshop community, it is fantastic to have you with us.

It is always best to follow the manufacturer's recommendations for installation, so it is best to use aluminium rivets with Colourbond products.

I notice that Eric has mentioned using Otter 3.2 x 3.2mm Open Aluminium Blind Rivets, which are indeed aluminium and fine for use with Colourbond products.

Where he mentioned galvanised pops, he is referring to these Abey Australia 75mm Round Standard Downpipe Pops which are used to connect downpipes into gutters and don't fall into the category of "accessory fasteners".

I hope this has clarified.

Jacob

[ChickenLittle]

Great thanks for clearing up the confusion!