How to upgrade downpipes?

[bowmatty]

Stormwater / Downpipe Upgrade Advice (QLD, 1985 House)

Hey everyone,

I’m planning on replacing my home’s downpipes and could use some advice.

The house was built around 1985 (QLD), and it currently has square downpipes. I’d like to swap them out for round PVC downpipes — partly for aesthetics, but mainly because the current system struggles with heavy rain.

• There are 4 downpipes in total.
• On the length of the house, 2 downpipes are spaced 21m apart.
• On the width, the other 2 are 12m apart.
• From what I understand, downpipes should be spaced every ~12m, so mine are definitely stretched.

My Questions:

1. Should I replace the square gutter adaptors riveted into the gutter (100x80x90) with round adaptors as well? Or is the hole too big to transition neatly?
2. Would you recommend running the pipes straight into stormwater, or leaving a small gap with a grill drain at ground level so I can see if it’s blocking up with leaves (we don’t have gutter guards)?
3. I’ve read that 90° PVC elbows can cause dripping noises — is that actually a problem?
4. We also have a decking area with a pitched roof that ties into the house. In torrential rain, water floods back into the eaves even though we’ve got catchers on the gutters. Any tips for fixing that?

The Plan:

Swap out all the downpipes for 90mm PVC, leave a gap above stormwater with grill drains for easier maintenance, and hopefully get better flow.

Has anyone here done something similar? Would love to hear your suggestions or pitfalls I should watch out for.

 

 

 

 

 

[AlanM52]

Hi @bowmatty 

CC: @JacobZ, @Nailbag, @Dave-1 

We live in 3150 and the (inherited) 2 story house was built in 1970 and has the smaller downpipes and yep... got sick of going up the extension ladder to clear the pops.

Downpipes are now 90mm PVC stormwater and in the last 12 years not had any blockages.

Pops were soldered so I used that Mini Soldering Torch Kit 135W purchased from ALDI to remove them.

Then enlarged the opening using Aviation snips for the 100 x 80 pop and also soldered them in (3 x pops).

I purchased those (as @JacobZ mentioned) secured either side with pan head self drilling screws.

 

Similar to what @JacobZ mentioned these are my 'dry joints' with some chook wire to block the rats for the back corners.

This is the 3rd downpipe at the front porch corner on the utility side of the house and if you look closely that's the gas main coming in from the street. Thanks to a plumber mate who cautioned me to be careful digging there, concrete slab with the gas meter just over the other side.

Cheers

[Nailbag]

Nice work @AlanM52 👍

[AlanM52]

Thanks mate,

They are still waiting to be painted 🙄

Cheers

[Dave-1]

Morning @bowmatty 

For a 21m run of gutter I still think there needs to be an extra dpownpipe in the middle. I would suggest to have a chat to a plumber/roofer to get the connection through the eve done properly. It dosnthave to be bang in the middle of the run, just somewhere "ish" to help carry that quantity of water you have going into the gutter.

Dave

[bowmatty]

Also, what ground drainage crates do you recommend? Circular or square and metal or plastic. I am indecisive as to what  

[JacobZ]

Hi @bowmatty,

There's not a whole lot of difference to tell you the truth, but a square pit would be a bit harder to clog.

If you don't have to mow around them, I would use the Everhard EasyDRAIN Aluminium Grate And Flo-Way Pits.

If you had to mow around them, so you want them to be a bit lower profile, I'd use Holman 100 x 90mm Storm ABS Finishing Collar With Grate.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob