Workshop
Ask a question

The Bunnings Workshop community can help with your home improvement projects.

How do I fix a rusty shed roof?

JamesP
Finding My Feet

How do I fix a rusty shed roof?

I know this question has been asked a few times, so apologies if I'm doubling up; I've read the other posts and wasn't sure if they apply to my situation.

 

I recently got rid of a bougainvillea on top of the garden shed, and found that a layer of dirt and pine needles had badly rusted the roof and even made a small hole.

20230303_153206.jpg

20230303_153215.jpg

 

I understand my two options are replacing the roof with new sheets, or using some kind of rustbuster combined with an exterior waterproofer.

 

What's the best option, given the scale of the damage?

 

I'm not sure what material the roof is (the shed was put up by the previous owner) but assume its galvanised iron? Here's a close-up of the sheet material.

20230303_153222.jpg

 

The hole is fairly small, about the size of a 20c coin.

 

There's five sheets on the roof, each one measuring approx 300cm x 87cm. 

 

Thanks in advance! 

 

James

Noyade
Kind of a Big Deal

Re: How do I fix a rusty shed roof?

Good morning James. @JamesP 

Personally - I'd replace the five sheets. Easily done and relatively inexpensive (steel merchant) with three metres being a readily available size.

Once in place - you'll never regret it.

How's the wood underneath?

 

Looking closer at your photo - maybe only four sheets? The far left looks OK?

Noyade
Kind of a Big Deal

Re: How do I fix a rusty shed roof?

Otherwise a LOT of elbow grease, wire-brushing and paint?

 

Interestingly and by coincidence, I was on a skillion part of my corrugated iron roof yesterday and wire-brushing small (nothing like yours) rust areas and painting.

Stupidly, I started at 1500hrs and finished at 1800hrs thinking it would have cooled down (and the metal) by then, but I found I was sweating so much, even with my big Bunnings hat on, the sweat was dripping onto the paint.

I found it extremely exhausting even with small rust areas, especially being old and still recovering from orthopaedic surgery. But I'm sure you're fitter than me. 😁

 

Paint wise I found this primer brilliant - it even stick to boots.

Cheers!

 

20230304_093724.jpg

 

I should add James, that 4-litre tin of primer is worth 2 sheets of 3m lengths of corrugated iron.

 

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: How do I fix a rusty shed roof?

Welcome to the Bunnings Workshop community @JamesP. It's wonderful to have you join us, and many thanks for your question about restoring a roof.

 

It's great to see that @Noyade has already been offering advice, and I'd agree that replacing the sheets would certainly be the best long-term solution. The sheets do appear to be galvanised steel.

 

If you were going to try and restore the roof, it would be best to remove the majority of the rust with a wire cup brush and angle grinder. You'd then be able to treat the rust with a rust converter before repairing any holes with epoxy putty. After sanding the repaired area smooth, you'll use a primer like @Noyade has recommended before painting

 

If you didn't want to paint the roof, then after converting the rust and repairing the holes, you could coat the roof with a brushable waterproofer.

 

The best option really comes down to how deteriorated the sheets are. If you take a flathead screwdriver and are able to punch holes in the sheeting easily, then I'd suggest that replacement would be a better option than repair.

 

Please let us know if you have further questions.

 

Mitchell
 

See something interesting? Give it the thumbs up!

Re: How do I fix a rusty shed roof?

Hello,

 

Thank you both for your help and suggestions - just wanted to let you know how it went.

 

I ended up replacing the sheets and it was pretty straightforward. 

 

I also used some of the old tin to make a wood shed.

 

Thanks again! 

20230306_073743 (1).jpg

 

 

EricL
Bunnings Team Member
Bunnings Team Member

Re: How do I fix a rusty shed roof?

Hello @JamesP 

 

Thank you very much for sharing that update. Your new roof looks excellent, I propose trimming all the trees around the area that's close to the roof of the shed to prevent the leaves and branches from settling on your new roof.

 

Eric

 

See something interesting? Give it the thumbs up!

Why join the Bunnings Workshop community?

Workshop is a friendly place to learn, get ideas and find inspiration for your home improvement projects