Restoring an Old Galv Iron Roof - to paint, replace, or wait?


I just moved into a place outside of Adelaide and I'm working through my building inspector's defect list, getting stuff up to scratch.

He suggested redoing the old roof bolts with proper tek-screws as they are lifting in a few places. Also, we are missing a couple of gutters, other gutters are sagging and overflowing badly, and we have a poorly plumbed rainwater tank that is dumping water near the house.

I have had a few guys out to quote these repairs (I am a useless handyman and bad with heights so no desire to get on the roof myself).

All 3 of them recommended painting the old galvanised iron roof as well. One said it would extend the roof's life, another said it wouldn't. The roof isn't rusty except for a couple of small spots but it is old. It would look much better painted or re-roofed, for sure.

Online, some people are saying it's a waste of money and will just put me up for more maintenance in the future when the paint comes off.

The main house is a 1920s cottage, which I believe was re-roofed in approximately 1980~ when they added a carport. So that's 40 years old. Some lichen, some lifting sections, and a little rust on the back of the carport.

There's also a mid-80s extension with a different roof, and a 90s extension with a different roof again. These are fairly flat skillion-style and not visible from the ground.

I am pulling my hair out trying to figure this one out. The roof repairs are generally quoted between $2 - 3k. I have a dedicated roof plumber coming out this week to do a quote too (as they have no interest in selling paint!).

The paint quotes are anywhere from $2k to $6k for the house. It's somewhere between 250 - 300 sqm of roof (rough guess due to the high pitch on the front).

I am trying to juggle a few issues:

  1. I want to put solar on the roof, sooner than later to start that lovely payback period. Once that's on there, I don't want to mess around on the roof too much.

  2. I'm not sure how long we'll be in the house. My wife is from overseas and we may move out some time. That could be 5 years from now, or 20. If it's 20 a reroof would be on the table - if it's 5, then maybe painting isn't so bad as it'll be the next guy's problem and cheaper in the short term.

  3. We are up for other renovations. In the short term it's a small bathroom. A year from now, we are likely to tackle a big one, redoing the kitchen, knocking out a couple of external walls, doing a lot of double glazing. Maybe it's worth sitting on it for a year, holding off on solar until then, and doing everything in one go. Advantages = more money in the offset for longer, overall less disruption since it'll all happen at the same time.

It's a badly insulated house so new sarking and roof insulation would not be a bad thing to my mind.

Thanks for any advice.

Poll Options

  • 1
    Paint the roof
  • 15
    Replace with new Colorbond on the roof
  • 4
    Wait a year and reassess
  • 1
    Put solar on this year without doing anything


  • New roof where you are putting solar.

    While this section of roof is off, install insulation.

    Replace screws yourself over rest of roof.

    New gutters and fix tank

  • +1

    why not replace the sheets where the solar goes, rescrew the rest

    • I'd really prefer to keep it totally consistent. Again, there may be a scenario where we sell in 5 years (possibly much longer!). The panels are sitting on the front of the house (North side) and the roof basically makes the first impression.

      I suspect if we were later to overhaul the thing, it would cost more doing it in two tranches than all at once.

  • +4

    I work in asset maintenance. Our AM strategy says to maintain at the lowest practical economic cost.

    Surface Protection (paint, galvanising) is one of our main treatments. If we can paint a sound roof for $3k with an expectation we will get another 5 years instead of spending $10k on a replacement that's what we'd do. That includes some accounting needs though as the paint comes out of maintenance budget and a new roof is capital.

    • You are certainly correct from a business side of things. Probably makes sense financially as well as far as keeping cash in the offset or for other purposes.

      That said, capex and opex don't quite apply the same way on my personal budget so still leaves something to think about!

      • capex and opex don't quite apply the same way on my personal budget

        That's why I mentioned it.

        Some of our painting jobs are so expensive we have to give the "surface coating" an asset number and depreciate it through capex

  • +3

    A new galvanised roof, it should last up to 50 years if you're not near a coastal area.

    While painting a roof looks nice I've seen several around which were painted in the last 5 or so years where the paint is lifting and fading, possibly bad workmanship, but painting is only expected to last for about 10 or so years.

    • So if that holds true, I guess we have 10 years left on the original section. Which isn't as long as you'd get out of solar. But is potentially longer than we'd be living here. Sheesh it's tough!

  • +1

    Been there and done that.

    Two Options (imo).

    1. Repair and Paint Over - about 15 yrs (which is pretty good, use a good painter and good paint (Regent or Dulux).

    2. Colorbond Roof - about 50 yrs (great option, no further headaches).

    Comes down to cost you are prepared to invest.

    Cheers and regards!

    • Thanks Lexus, 15 years is longer than I expected. Most of the guys who have come through offered the same paint product (undercoat + 2 overcoats of the Dulux roofing stuff).

      Of course the quotes varied wildly, as did their measurements. One guy eyeballed it (he came highly recommended and was the cheapest), another measured from the ground, the last one got up on the roof and looked around.

      I might check what a re-roof will cost from those fellas just so I know.

  • Are you living in my house?

    I'm in a similar situation.. old house, old roof. Curious to see people's thoughts.

    I'm leaning towards new roof. Redo insulation at same time. Then take a look at updating the windows to double glazing.

    Good luck!

    • Yeah it's a big mix. I posted on Whirlpool too and a lot of opinionated folks said painting is never worth it, and the other repairs I could do myself (perhaps, but I really am useless and don't want to fall off a roof).

      Our place is horribly insulated too. There are old fibreglass batts in the roof, but it's raw iron above, no sarking or anything. All single glazing throughout (I have a funny glass hallway feature with about 35 sqm of very thin glass which saps any warmth out). We have only been here a few weeks, but most days you can see your breath it's so cold, all through the day. I imagine in Summer it'll heat up very quickly too.

      I have some insulation guys coming to take a look. Maybe they'll point me in the right direction hah.

      • Thanks for the response - I'll go over and have a look at your whirlpool thread :)

        • No worries! Might be a few pages in.

          Let me know how you end up going too. Had another chat with my inspector and he suggests getting it painted to seal it up and prevent corrosion is not a bad idea.

          In the end it'll come down to budget I guess. Definitely a smaller hit to go with the cheaper contractor I found for a paint. But maybe I will get a new roof & sarking quoted out just in case.

          Need some cash for the bathrooms, a bit of structural landscaping and other stuff! Sheesh!

  • +1

    If you are going to move potentially then do as little as possible. I probably won't even put solar in due to the solar tax that might be coming unless you have a clear strategy to make it pay in 5 years time. Wouldn't paint the roof, it is good for presentation (if you are selling) but not if you are living in it.

  • I think painting isn't a bad option, however ensure that you make sure you get the painter to provide the full 15 year warranty that Dulux offers. You want to make sure the painter follows exactly how Dulux suggests you prepare Galv roofing as well -

    • Thanks mate. All three described the same process (high-pressure clean, wash etc, undercoat, two overcoats) and are quoting the same product from what I can tell.

      They are all well reviewed as well. But the discrepancy is pretty crazy. Including the guttering fixes, it's $4k vs $6k vs well over $8k.