Restoring and painting old corrugated "iron" / metal roofing sheets (galvanised)

[carbs for arbs]

Hi

 

I was donated some "corrugated iron" sheets and have been using them for a couple of years in a makeshift shanty town style array to cover firewood. I want to build proper wood shelters before winter and plan to make use of these sheets. But I'd like to clean them up and protect them as part of the project. It doesn't have to be amazing, the main objective is just to make sure they last as long as possible.

 

I'm pretty sure the sheets are galvanised. There's some old black paint in them which has blistered, flaked and peeled in places. There's also remnants of an old orangey/rusty coloured paint on them which you might mistake for rust at first glance. That being said, there is some rust in places but they're not too bad overall.

 

Bitumen paint seems a common choice. What do you guys think to that? Or are there better alternatives? Also, would I need to use a primer or anything else prior to painting? I've read about rust inhibitors, etch primer, and various other things, some of which people say you should use on galvanised, while others say not to. So feeling a bit confused and hoping you guys can put me on the right path.

 

Many thanks

 

PS - I will be fixing them down properly. Please ignore all the wood and rocks!

 

 

 

 

 

 

 

 

 

[david lawrence]

Weathered side won’t need primer 

[Nopedigree]

I suspect that unless you are in your teens a quick stuff brush off, a coat of bitumen and a decent angle on the roof they will see you out.

 

NoPedigree

[Steven P]

I think paint would be just for the look of things - the sheets have lasted well so far, your couple of years plus the life they had before.

 

So if you want them to look nice an undercoat and top coat - paint for metal of course will do the job, hammerite should do.

 

The only point I would worry about are where you drill fixing holes - galvanising is a surface treatment so you loose that on the edge of the hole - you can get a spray (Halfords?) if that is all you need to do.

 

However if it was me and wanted them to look prettier, I'd go hammerite.

[Peasgood]

I would choose from Skip paint, Bedec barn paint or floor paint in that order. Any of them would do a great job.

[spuddog0507]

i would guess that the black paint is bitumen, and bitumen is the way i would go for 2 reasons, 1 it goes on well and will protect the metal well, 2 its a log store and the black bitumen on the tin will absorb heat during the day and this will help dry your logs out, back in the late 70s i worked at a local sawmill and the old guy had a tin lean to on the back of a building that was just painted with bitumen and this really warmed up in the day, some days it was my job to barrow some logs across and stack em up in this lean to and some days the heat was unbearable, he just called it his solar shed,,

[Muddy42]

I'd have a think about cost/benefit before doing this - cost of new corrugated iron sheets someday in the future (£15?) which wouldn't have holes in, versus cost of paint and cost of your time.  Corrugated iron takes a fair bit of prep and is awkward to paint.  I've painted them where they are already bolted onto a roof (with inbuilt labour to get them there) but I'm not sure I'd bother with loose sheets?

Edited August 23 by Muddy42

[peds]

13 hours ago, Nopedigree said:

I suspect that unless you are in your teens...

 

Odd thing to shoe horn in there.

 

To the OP, a layer of membrane underneath manky old sheets can solve all sorts of problems... old polytunnel plastic, radon barrier, roof membrane, silage plastic... whatever you can find. Doesn't matter if there's a few holes rusted through the metal if any drips are carried away anyway.

 

Kind of adds to the upcycled aesthetic, too!

[carbs for arbs]

Many thanks for the replies, much appreciated.

 

16 hours ago, david lawrence said:

Weathered side won’t need primer 

 

Does that mean the un-weathered side will?  

 

 

15 hours ago, Nopedigree said:

I suspect that unless you are in your teens a quick stuff brush off, a coat of bitumen and a decent angle on the roof they will see you out.

 

NoPedigree

 

I wish!!!  Approaching 50...  Good to hear a thumbs up for bitumen, as many seem to be suggesting more expensive alternatives.  

 

 

15 hours ago, Steven P said:

I think paint would be just for the look of things - the sheets have lasted well so far, your couple of years plus the life they had before.

 

So if you want them to look nice an undercoat and top coat - paint for metal of course will do the job, hammerite should do.

 

The only point I would worry about are where you drill fixing holes - galvanising is a surface treatment so you loose that on the edge of the hole - you can get a spray (Halfords?) if that is all you need to do.

 

However if it was me and wanted them to look prettier, I'd go hammerite.

 

I think the problem is there is already rust creeping where previous holes are, as well as around edges.  And I wondered if it would get worse exponentially once it takes hold.  Looks wise I'm not too bothered and actually quite like the look of them as they are.  But seeing as they are only temporarily fixed and the shelters need doing proper, whilst down I thought it made sense to give them the best possible chance of a longer life.  But not doing anything would be the ideal IF painting made no difference.  

 

Happy to patch paint over both the screws and holes after fixing them down.  Makes sense.  

 

Hammerite says it doesn't need an undercoat/primer?  

 

Also, Hammerite seems about x2 / x3 more expensive than bituminous.  Do you think it is worth the extra outlay?  Longer protection?  

 

 

14 hours ago, Peasgood said:

I would choose from Skip paint, Bedec barn paint or floor paint in that order. Any of them would do a great job.

 

Thank you, I'll take a look at those options.  

 

Do you think they are all better options than bituminous, and if so do you mind if I ask why?  

 

 

14 hours ago, spuddog0507 said:

i would guess that the black paint is bitumen, and bitumen is the way i would go for 2 reasons, 1 it goes on well and will protect the metal well, 2 its a log store and the black bitumen on the tin will absorb heat during the day and this will help dry your logs out, back in the late 70s i worked at a local sawmill and the old guy had a tin lean to on the back of a building that was just painted with bitumen and this really warmed up in the day, some days it was my job to barrow some logs across and stack em up in this lean to and some days the heat was unbearable, he just called it his solar shed,,

 

Another vote for cheap option, that's encouraging   

 

 

4 hours ago, Muddy42 said:

I'd have a think about cost/benefit before doing this - cost of new corrugated iron sheets someday in the future (£15?) which wouldn't have holes in, versus cost of paint and cost of your time.  Corrugated iron takes a fair bit of prep and is awkward to paint.  I've painted them where they are already bolted onto a roof (with inbuilt labour to get them there) but I'm not sure I'd bother with loose sheets?

 

Thanks, that's good to look at things from another perspective.  Tbh, I do prefer to reuse where possible.  My time is free.  And the equivalent sheets after a quick look seems to be coming in at around £25-£30 each before delivery.  I'm estimating I'd need around 25, maybe a little more.  So quite an outlay, but worth bearing in mind.  

 

 

2 hours ago, peds said:

 

To the OP, a layer of membrane underneath manky old sheets can solve all sorts of problems... old polytunnel plastic, radon barrier, roof membrane, silage plastic... whatever you can find. Doesn't matter if there's a few holes rusted through the metal if any drips are carried away anyway.

 

 

Thanks for the tip.  I've actually been really surprised (pleasantly) at how little water gets through them, even with existing holes and damage.  The wood is staying very dry.  Still, the drier the better so I'll see what I've got laying about and/or what I might be able to get my hands on.  

 

 

Cheers all

 

[Steven P]

If it's just to stop the rust spreading around the holes and cut edges wire brush off the rust - use rust remover if you want - and then a galvanising spray over the where the rust was and any new holes or cuts you make should do the job.

 

I did fill a hole in the garage roof with bolt / washer and some bitumus paint - did the job OK so yes, cheap and cheerful will work to - all depends on the finished look you want