How to calculate guttering brackets and fall needed?

Hello all,

I need to replace old guttering with new guttering and need to understand the spacing of the brackets. My length of guttering is 4.4 metres. How much space do i leave for the stop ends, would it be 150mm and then that leaves me with 4.1 metres between brackets. So, what would be the spacing for that 4.1 metres. Also, what would be the fall from the high point to the low point on 4.1 metres of guttering as i read for every it is 2mm of fall. So, if my highpoint was 12mm would my low point be 20mm. I look forward to what people have to say.

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Comments

EricL

Hi @nightrider_aus

Thanks for sharing your question about your guttering.

Replacing your old guttering becomes much simpler when you have the spacing and fall measurements worked out. For the brackets, standard practice is to space them approximately 900mm (0.9m) apart to ensure the gutter is well-supported and doesn’t sag. Given your gutter length of 4.4 metres and allowing 150mm at each end for the stop ends, this leaves you with 4.1 metres to work with. Dividing this length by the recommended 0.9m spacing results in approximately 4.5 brackets.

Since you can’t install half a bracket, you’ll need five brackets in total. To space them evenly, divide the 4.1m length by the number of gaps between the brackets (five brackets create four gaps), giving you a spacing of roughly 1.025 metres, or just over 1 metre between each bracket. Start the first bracket 150mm in from the stop end and work along the gutter length.

For the fall of the guttering, the general recommendation is 2mm per metre to ensure proper drainage. Over your 4.1-metre section, the total fall required would be 8.2mm. If your high point starts at 12mm, the low point should be set at 20.2mm, maintaining the 2mm per metre slope. This gradual fall will allow water to flow smoothly toward the downpipe without pooling.

With these measurements, you’ll have a well-spaced and correctly sloped guttering system. Brands like Lysaght, Colorbond, or EasyDRAIN, available at the store, often include handy guides for installation, which can provide additional reassurance as you work.

If you need further assistance, please let us know.

Eric

nightrider_aus

https://www.workshop.bunnings.com.au/discussion/comment/45958#Comment_45958

Thanks Eric,

The feedback was great. I look forward to my next discussion with you.

Regards,

Marco.

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