So you have a gutter leak and want to know how to fix it? If so, this article is for you. I’ll explain the common causes of a leaking gutter and what to do next.
Note, if you’re gutters are overflowing when it rains rather than leaking, then check out our overflowing gutters article for reasons your gutters are overflowing and what to do about it.

Signs of a leaking gutter
A leaking gutter occurs when you have water somehow leaking from the base of your gutter or around where the downpipe connects to the gutter.

Signs of a leaking gutter are usually where you can see drips or trickles of rainwater seeping out from the base of your gutter.
This is often noticeable directly after a downpour when you still have rainwater sitting in your gutters.
Areas this usually occurs include:
- Gutter joints where two pieces of gutters or joined together
- Gutter corner joins
- Downpipe connections (where the downpipes join the gutters)
Leaking Gutters are not always visible!
Sometimes, the leak might be coming from a box gutter that is up in the middle of a roof rather than hanging off the edges of a roof (common with flat roofs). If this is the case then the leak may be dripping from the box gutter directly into your roof space or eave.
In addition to this, if you have downpipes running through your eaves and connecting into the back of your gutters the leak may be running into your eave space.
If this is the case then signs such as water mark stains on your eave lining or on your ceiling under the area of the box gutter can be a good indication that water is leaking out into your eaves or ceilings.
Causes for leaking gutters
There are a number of reasons why your gutters may leak. Below is a list of the most common occurrences I’ve come across.
Rusting gutters
Overtime a long period of time, if gutters are not maintained well and water or debris remains in your gutter, this can lead to your gutters rusting.
When the base of your gutters starts rusting small cracks and holes will appear in the metal gutter, allowing the rainwater to leak out the base of your gutters.
Poor gutter or downpipe joins
Another common reason is that your gutter joins or downpipe connection joins haven’t been done properly or not enough gutter silicone applied.
This can lead to rainwater leaking out through the holes.
How to fix a leaking gutter
The first step to fixing a leaking gutter is to identify the cause.
Looks like my gutters are rustedโฆwhat should I do?
If you’ve checked the base of your gutters and you can see that they’re rusting out then you have a couple of options to consider.
Replace the rusted piece of gutter
The first, and recommended option is to remove the rusted gutter and replace it with a new piece. Gutter lengths usually come in 6m lengths hence you can always look at replacing a much larger piece than just the rusted area as the chances are if one area is starting to rust other parts of the gutter are too.
Note, however, that replacing gutters isn’t always as straightforward as you may think I would advise engaging a roof plumber to do this.
Fill the holes
More of a temporary, cheaper option would be to clean off the rust and any debris surrounding the rusted holes in the gutter (using a wire brush) and then apply the likes of weatherproofing tape or roofing sealant.
Note, if youโre going down this path always ensure the area youโre applying silicone or tape to is bone dry else it wonโt bond to the gutter.
Appears there is a leak at a jointโฆ
If you can see there is a leak at the joint then this may just be a matter of using some roofing silicone to re-seal the joint. Below are some steps to follow:
- Clean any debris or dirt from around the join;
- Once cleaned, wipe it down with a cloth and ensure itโs bone dry;
- If there is any old or flakey silicone, use a blade of a Stanley knife (or something similar) to scrape away the old silicone;
- Inspect the silicone and the join area to see if you can identify the hole;
- Get some roofing silicone (I recommended the grey colour for inside gutters) and apply the silicone on the area where you suspect the leak;
- Using your figure, work the silicone into the hole using a circular motion.





