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Gutters

(15 posts) (9 voices)

Started 2 months ago by Una Fini
Latest reply from Una Fini

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Una Fini
Member

Does anyone know of the BEST guttering system for subtropical Australia? I've been here 40 years, in 6 different houses... never been happy with any of them- quad, box etc. AND systems for gutter guard are bad news as well. I've looked into Smartflo gutters but they are hopeless at replying to enquiries. I need new gutters now. The 80s brick house we bought has one downpipe over 24 metres! Old box type. Badly installed w not enough slope as well. Then the smarties planted huge gums all around the house to insure gutters fill with leaves every fortnite. The gutter guard was put in backwards (cheese grater holes) so water flowed over the guard with very little being collected.

Considering 1/2 round gutters with perhaps 3 downpipes over the 24 metres. Not convinced this is the way to go but have to do something before these gutters fall apart.

Posted Friday 2 Feb 2018 @ 9:02:04 pm from IP #
Diver
Member

Half round gutters have the most efficient flow and flushing performance.

You mention box gutters, do you have a combination of eaves gutters and box gutters?

The gutter's cross sectional area and the downpipe's size needs to accommodate your area's Average Recurrence Interval (1:20 for eaves gutters and 1:100 for box gutters) and the roof area drained to each downpipe. It is invariably the gutter and not the downpipe that causes overflows.

Having downpipes a long distance apart means that the slope will be compromised and this promotes slow drainage and debris build up. An adequate slope over a long distance can be done with the correct gutter design and size but aesthetics can then come into play due to the height difference needed between the gutter's high and low points.

Posted Friday 2 Feb 2018 @ 10:47:22 pm from IP #
Chip
Member

Check out Tornado rain heads. From Perth. They relace a short section of gutter with a funnel shaped connection to 100mm downpipe. In heavy rain they set up a vortex which results in a lot of water entering downpipe compared with usual setup. If you have a charged system or other system restriction you could consider a bypass that sends water to open air once the level in downpipe reaches near to gutter level.

Posted Sunday 4 Feb 2018 @ 7:26:14 am from IP #
jdaley
Member

1/2 round gutter is fantastic.
With better railheads etc you should be ok, the Tornados look and operate well, but you still need to keep dirt and leaves out of the system somehow.

Posted Sunday 11 Feb 2018 @ 12:17:51 pm from IP #
Johnnojack
Member

Have a further question for the experts. We are using half round gutters but have one section of box gutter. What would be better a box gutter with a flat base or one with a slight vee shaped base. I have seen lots of flat ones and often they retain water which turns foul. (We are collecting the rainwater for whole house use). A further complication is the roof on one side is only 11 degrees and building up the base to enable a flat section will mean the gutter will be very wide to get any decent cross sectional area ( volume).

Posted Monday 12 Feb 2018 @ 11:18:07 am from IP #
dave lawrence
Member

when you say box gutter, do you mean a gutter above an internal space. ?.. because that is what a box gutter technically refers to. As opposed to an eaves gutter...which is outside the building line . box gutters are commonly used above butterfly rooves and other such complicated rooflines beloved by architects and loathed by builders .Loathed because all builders know of their propensity to leak eventually .
If you were talking about box shaped eaves gutters , on the other hand that is a different matter . It is good to differentiate between the two before getting into al ong winded idscussion which might be irrelevant to yuor question .

Posted Tuesday 13 Feb 2018 @ 5:26:24 am from IP #
dave lawrence
Member

a true box gutter can be built to not leak ,but it takes a lot of thought and care in the construction of it ,and I believe is largely dependent on the supporting structure underneath the actual sheet metal which is supposed to take the water away. one consideration is access to it ,to be able to clean it out regularly .

Posted Tuesday 13 Feb 2018 @ 5:28:39 am from IP #
Johnnojack
Member

Yes it is over living space, 6 m long gutter, the roof on one side is 30deg and 7.5 metres to the ridge, the other side is 12 degrees and 4.5m to the ridge.

Posted Tuesday 13 Feb 2018 @ 10:25:46 am from IP #
dave lawrence
Member

i would want minimum width of tray at 300, preferably 450. 17 thick ply substrate under fully suuporting the metal . gutter should be minimum 250 deep, probably more. include overflow options etc . expensive to do properly ... but cheaper than trying to fix up later !!! insist on builder or plumber guaranteeing the design will cope with 1 in 100 year flood., in writing . insist on design being approved before construction. if you could have the tray done in one piece folded up all the better .

Posted Thursday 15 Feb 2018 @ 3:42:06 am from IP #
amun-ra
Member

and all done in stainless steel as Ive had to replace several of these and its costly and just not a fun job

Posted Thursday 15 Feb 2018 @ 8:17:26 am from IP #
Catopsilia
Member

Dave Lawrence says:
"insist on builder or plumber guaranteeing the design will cope with 1 in 100 year flood".
I am not sure that anyone can guarantee that, but I find that the Building Code of Australia requires that the design of gutters should take high intensity rain storms into account.
For NSW, (the NSW Government Office of) Fair Trading has a web-page "Roof plumbing - roof drainage systems":
http://www.fairtrading.nsw.gov.au/pdfs/Tenants_and_home_owners/Roof_plumbing_guide.pdf

This web-page covers "new buildings or renovations requiring development approval". I guess if your project is not with development approval, you are on your own.

It is not actually a "1 in 100 year flood" that is to be considered. The relevant Standard (AS/NZS 3500.3) specifies five-minute-duration rainfall intensities and refers to Average Recurrence Intervals (ARI) of 20 and 100 years. Box gutters should meet the ARI of 100 years, because the damage when they overflow will be severe.
The 1 in 100 year event may seem very rare. It is better to think of it as an event that has a 1% probability of happening in any one year. Such as this year, for example!

Posted Friday 16 Feb 2018 @ 3:03:26 am from IP #
Diver
Member

Box gutters are now mandated to have an overflow to atmosphere that is not less than the design flow of the associated gutter outlet.

Posted Friday 16 Feb 2018 @ 4:48:09 am from IP #
Bushwalker
Member

Yay!

We don't have any of those now, but previously they were a total disaster if the outlet had leaves clogging the water out - flooded into the ceiling.

Would never have them again, but if they are designed to flow outside instead of the ceiling that is a good mandate!

Posted Friday 16 Feb 2018 @ 5:28:50 am from IP #
Diver
Member

The gutter outlet discharge is as always, the overflow to atmosphere is the emergency overflow provision that must now be incorporated into the design.

My manufacturer had an extension made last year and there had to be a box gutter. The plumber left plastic in the gutter, it rained and the gutter flooded back down a separation wall and flooded into both areas. Turns out that the box gutter wasn't designed with the mandated overflow provision.

The plumber also replaced the eaves gutters and fitted the new ones at the top of the facia!

You can never legislate against stupidity.

Posted Friday 16 Feb 2018 @ 11:17:36 am from IP #
Una Fini
Member

Thank you for all the helpful repllies. Sorry I used "box gutter" to describe what we have...it is the run of the mill square one w slots along front to allow overflow. No matter really as now replacement is urgent. One side of house gutter has split along these weep holes...no water going to tanks.

While 1/2 round would be my choice IF I can't figure out this other system...then I also have to have gutter guard as well...which I hate.

The other system...hoping someone out there knows of it and has done it. I've been told its used in New Guinea. 100 mm storm pipe (and oddly enough, this is the size that is UV treated!) Slit open and then fit over the edge of tin - provides a clean run of gutter plus leaf guard in one. NO internal brackets to clog up. This would be my ideal. Problem: How to bracket it on from outside... How to clean it when you do need to flush it out? Screw caps on ends not good enough if its going 24 metre length. Perhaps drill in wide enough holes along top to insert hose...then cap them w plug of some kind? There has to be someone out there who has used this?

Posted Saturday 24 Feb 2018 @ 9:02:18 pm from IP #

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