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How to fix leaks from polycarbonate roof flashing under tile?

So I've just replaced all the roofing sheets under outdoor spa-room with new Suntuf Trimdeck polycarbonate sheets, however I'm still getting leaks even though I replaced the old roof because it was leaking.

What would be my best solution to stop the leaks? I've tried to add the foam infill under the tiles however due to the trimdeck profile, every 4th valley of my roof tiles sits on the peak of the trimdeck roof. I'm pretty sure the weight of the tiles on these peaks is causing the polycarbonate to sag and water is flowing back under the tiles. It is also pushing the tiles too high exposing gaps on the sides which is also letting water into the roof cavity.

Please help.

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Comments

EricL

Hello @Helmutson

Thanks for sharing your question about your polycarbonate roofing. Can you please provide us with a little bit more information. Are the leaks occurring where you've placed the fixing screws? Are they showing up where the Suntuf panels overlap one another? Are any of the tiled roofing leaking or leaning against the Suntuf panel. Is it possible that water is bridging along where the tiled roof meets the Suntuf panel?

You can easily track the leaks by using your garden hose on the Suntuf panel. Have one of the family members spray the roof while you stand underneath it. Once you spot the leak you'll have a much better idea of its cause.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you have any other questions we can help with, please let us know.

Eric

Dave-1

https://www.workshop.bunnings.com.au/discussion/comment/45607#Comment_45607

Afternoon @Helmutson

Mmmmm I am having pictures of my sunroof under the tiles...

I have corrorgated metal sheets and the point where they meet up cobstantly backs up with leaves...

It looks like your new suntuff roof tolerance from tile to suntuff sheet is very low and as you suspect that is whats causing the leeks 😕

There are only two things I can think of, if this is the case. Fill the span between the roof trussses with timber that will hold the tiles off the suntuff sheet. I know its only mm's but that could help. (please note that its probarly not wise to kink the last row of tiles at a differant angle to the slope of the roof)

The second one is to change the pitch of your suntuff roof, that would be a lot of work but less chance of water pooling and running backwards.

Just one last look at your photos and I notice the third phot shows a screw that hasnt had teh rubber compressed (the one to the left is compressed slighly) I wonder if the water is also entering via those holes as its directly under the valley of the tile and the rubber isnt compressed to make waterproof?

@EricL has suggested a good way of narrowing down where the water is entering 🙂 Id try and see what points it enters and then work backwards.

What did you have there before? and what was the height profile of the sheets?

Dave

Helmutson

https://www.workshop.bunnings.com.au/discussion/comment/45607#Comment_45607

Hi Eric,

Thanks for the reply.

I did try hosing the roof and that's how I found the leaks. It looks like it is leaking both where the valley of the tiles lean on the peak of the polycarbonate and where the tiles have gaps on the sides.

The more I try to force the tiles down so they meet up better the more it compresses down on the peaks of the polycarbonate.

I was thinking of cutting the polycarbonate just behind the screws of those peaks that are being forced down to allow the tiles to drop down, but I assume that will lead to more leaking. I have about 100mm of polycarbonate sitting under the tiles.

I've uploaded a picture from the side showing the peaks that are being forced downwards.

Would a line of silicon behind the screws just in front of the foam infill help to create a dam, stopping water draining backwards?

EricL

https://www.workshop.bunnings.com.au/discussion/comment/84910#Comment_84910

Hello @Helmutson

As much as I would like to agree in regards to creating a dam on the Suntuf panel it is not ideal as this will cause mould and mildew to settle into those wet areas. Technically the fall must be increased in order for water to flow way, I'm thinking perhaps the front of your roof frame can be planed to create a fall as by the look of things there is no more space between the tiles and the polycarbonate.

Let me call on our experienced members @Jewelleryrescue and @alicanterenodb for their recommendations.

If you need further assistance, please let us know.

Eric

Nailbag

Hi @Helmutson

Unfortunately I don 't really haver any easy solution options for you as it's an unconventional method of continuing the tiled roofline over to the pergola. Below are a few examples of what would normally be constructed which overcomes any issues of mis-match in the tiles to poly transition.

What is important is to seal up all those large gaps in the tiles. Water wont be just leaking through in to your outdoor area, but more seriously into the house roof-space. I would recommend using a product such as Sika 11FC for this.

Nailbag

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Nailbag

https://www.workshop.bunnings.com.au/discussion/comment/84910#Comment_84910

Hi @Helmutson

I was working at a home today that had albeit a very small overlaying poly roof line, I thought the photos may also help.

Regards, Nailbag

Helmutson

https://www.workshop.bunnings.com.au/discussion/comment/107573#Comment_107573

Thanks for the pics mate .

That setup looks interesting. It looks like that aluminium flashing starts after the tiles finish, and there is a little transition piece that slope back towards the underneath of the tiles which is weird. I wonder where the water goes to?

ppppistachi

Hi mate.
In had this installed a few years ago and you have no idea how many times I went onto the roof to try and fix this. It’s the capillary action of these sheets. No matter what I did it to prevent the leak, another section of the roof would leak! It’s actually unreal. It’s like a tom

and jerry cartoon! I went to the extent of spraying a silicon spray between the joints - this worked. However it would just appear on another end.

EricL

https://www.workshop.bunnings.com.au/discussion/comment/48237#Comment_48237

Hello @ppppistachi,

Welcome to the Bunnings Workshop community. It's sensational to have you join us.

Thank you for sharing your knowledge and experience in regards to the leaking polycarbonate roofing.

We are keen to hear more about all your projects and plans around the house and garden. Please feel free to reach out whenever you need assistance or would like to share a project with the community.

Eric

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