How to find leak in patio roof?

Question

Hello guys

My house is about 40 years old. The rear patio has a flat metal roof and was supposed to have been properly re-screwed along with the rest of the roof about 2 years ago.

Are you able to guess where the leak might be coming from? Could the water be coming in through the roof (loose screws?) and through the spaces where the fittings abut the timber?

The leaking only seems to be around a few of these fittings and in the centre of the ceiling (so the water doesn't seem to be leaching in from the sides of the house / gutters I don't think).

There is a fair bit of mould on the patio ceiling as well. So I'd like this tackled properly first before fixing the mould. Also, what are those timbers called that the fittings are attached to? It looks like there's a type of silicone or glue around them. Could this have degraded too?

Would appreciate your advice.

Thank you.

LorenClayton · Answer

Thank you MitchellMc. I'll update and let you know once the gutter vacuuming is done.

MitchellMc · Answer

Hi @LorenClayton,

The first step should definitely be to have the gutter cleaned out. From the photos and your description, there is quite a significant amount of debris sitting in the box gutter, and during heavy rain that can easily restrict the flow of water and cause the gutter to overflow, which may be the reason you're seeing leaks in the patio ceiling.

Until that debris is removed, it's very difficult to properly assess whether there is another issue, such as a fall problem, blockage at the outlets, or a small hole or joint failure in the gutter itself.

If cleaning the gutter resolves the leaking during rain events, then there really wouldn’t be any reason to modify the current setup.

Regarding your question about adding flashing down the middle of the patio roof, I may not be fully following what is being proposed. From what you’ve described and the layout, it sounds like the patio/pergola has its own independent box gutter. Installing flashing to divert that water into the house gutters may not achieve much and could potentially increase the load on the house guttering system, which generally isn’t ideal.

Once the gutters are cleaned, the contractor will also be able to inspect the gutter more clearly and check for things like holes, failed joints, or areas where water might be escaping. Until that’s done, it’s mostly speculation about what changes might help.

Given the nearby gum tree, you may also find that periodic gutter cleaning will be necessary to prevent the same issue from occurring again.

Hopefully, once the gutter is cleared, you’ll have a much better idea of whether any further work is actually needed.

A thought about the "kissing" gutters: Between their lips, where they touch, there is a gap where water can pool. That water would leak down between the two gutters and could potentially be some of the water you're seeing beneath. A bead of gutter silicone along this gap would likely help reduce water ingress.

Please let me know if you have any questions.

Mitchell

LorenClayton · Answer

ello guys

My rear patio (flat roof) ceiling leaks during heavy rain. I had the roof - Colorbond Trimdeck - inspected yesterday. Photos show the gutter which runs down the middle is full of debris. The culprit is my neighbour's huge gum tree.

I was told the box gutter might be weighed down by all the debris. He wasn't sure if the gutter's fall was still OK so recommended they gutter vac first to see if leaking stops. Was quoted $550 to vacuum the whole roof.

The question is: is it better to have a split in the patio roof where debris can easily accumulate, as in my case, or would it be better to have flashing down the middle so the water is diverted into the house gutters?

Is this called a "kissing" gutter? (see photos). I was told yesterday it's a box gutter. AI says this is to protect the house from patio gutter overflow. If so, then the current system is probably safer.

Either way I will have to have the gutters cleaned out periodically. I've got 4 drains around the house.

Would appreciate advice on which way to go - block off the patio roof with flashing or keep current system as is. Thank you.

Another issue is the roof screws. This were all replaced with new class 4 screws November 2024 (a different contractor). The inspector yesterday said they shouldn't be this rusty after such a short time. I live at Clontarf not far from the ocean. I'll include these photos too as wondering whether I should complain to QBCC. The roofer's invoice says there's a 2 year warranty but the company didn't reply.

In the overhead photo, rear patio has the stripe on it.

Thank you, and appreciate all your help.