# Forum Home Renovation Roofing  Colorbond roof fading and rusting

## Smurf

I have a red Colorbond roof that seems to be deteriorating. The house was built around 1994 and the roof has faded a little to be more of a dark pink colour than red. 
But what I'm more worried about is what I noticed when I did a closer inspection this week. On the "bottom" of some of the corrugations near the heater flue the colour has changed to white. In some parts there is bare metal visible and in one small patch (roughly 20mm x 5mm) it's noticeably rusting. 
What to do? I'm not worried about the colour fading but rust is obviously a more serious problem. Can I somehow treat the rust then paint over the parts where the colour has come off? What with? Just ordinary paint? And what about the rusty bit?  
Thanks in advance for any advice.  :Confused:

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## Honorary Bloke

Yes, you can get "rust killer" paints and primers that neutralise the rust (even Bunnies should have it). If they are small areas, you can get a can of spray. Then paint with suitable paint any colour you like.  But get on the rust quick smart.  :Smilie:

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## Vernonv

What sort of warranty do you have on the roof sheeting? ... maybe you should contact the manufacturer. 
... I just checked the Bluescope website and they offer a 12 year paint peel or flake warranty and a 30 year perforation warranty.

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## henlan77

Definitely worth contacting the manufacturer. In my area the local steel supplier has been flat out replacing roofs under warranty!

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## Make it work

Are you close to a beach with rolling surf or an industrial estate, by close I mean within 1 or 2km? 
This is most likely to be the one of the first questions the manufacturer will ask but it is definately worth asking about warranty, the worst they could say is no.

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## Smurf

> Are you close to a beach with rolling surf or an industrial estate, by close I mean within 1 or 2km? 
> This is most likely to be the one of the first questions the manufacturer will ask but it is definately worth asking about warranty, the worst they could say is no.

  Water is a few hundred meters away but it's a sheltered bay and very calm.  
There's heavy industry across the river upstream a bit. They did do a lot of research into the "fallout area" from that factory as it's been there for 90 or so years and quite a bit of dust etc was released in the past - it's nothing drastic but you don't want your kids playing in contaminated soil. Bottom line is I'm near but not in that zone and my neighbours roofs seem OK. 
I'm thinking that my own heater may be a factor as the corrosion is very near the flue. I use dry wood and make sure the fire burns properly so it doesn't belch smoke, but I only moved in this year and it's possible that the previous owners could have burnt things they shouldn't (like plastics etc) and I'm thinking that could have caused an issue. If I look at where rain that hits the top of the flue will run off to, then that's exactly where the corrosion is.  
Thanks everyone for the responses. I'm off on holidays tomorrow so I'll have to leave it until next week before having a proper look at everything and deciding what to do. :Smilie:

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## barney118

I would look more closely on how the flue's heat could be a factor in the corrosion, check to see what the flue is made of as if it is galv then you will have some issues with "dissimilar" metals which can cause corrosion. The other to look for would be is the flashings the same issue or do you have them? The other being the heat from the flue, should it have some sort of insulation? as is it cooking the surrounds constantly.

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## barney118

Smurf, forgot to mention, "white" discolouration sounds like Zinc not Zinc/Aluminium oxide as the Al oxide is very protective when it corrodes hence why they use Z/Al as the base coat on colorbond, but pure GAL (Zinc only) forms a white powder. So it sounds like you have some Gal causing the grief, Check the underside of the sheeting to see if there is any 'branding" as you could have been duped by paying for "Colorbond" but getting something else. Did you get a warranty certificate from the manufacturer? My guess is still look for where the Gal is I suspect the flue or flashings and replace the sheeting and change the flashing to Colorbond or insulate/ seperate the flue from touching the sheeting.

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## Make it work

Does the flue have a lead flashing? It just occured to me that lead and Colourbond don't play nicely together, Just a thought but worth mentioning.

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