Best paint for a galvanised/slightly rusted metal roof?

[scodiy]

Hello all.
My garage roof is galavanised metal sheeting which is rusting in parts. I've been tackling the rust with Neutrarust 661 (other products are available) but am still looking for a good quality paint to seal it with. Hammerite is out because a) it's expensive and b) doesn't perform that well outdoors anyway, at least not here in North East Scotland.

I've spent hours trawling the Internet but it always comes down to just picking something and taking a gamble, and in many cases the paint is expensive and isn't available in a match pot size to try out.

I did come across a company called Turners Trade Paints that had some interesting products but, like many British companies I contact with an enquiry, didn't bother getting back to me.

Does anyone have any experience? The roof area is about 50m2 in total, so although I'm willing to pay for quality it does have to be reasonable price-wise.

Any suggestions gratefully received.

 

[Housey210]

I use this product- EVERBUILD GREY EVERCRYL ONE COAT. Years ago it was something called Fillcoat, very pungent! Patched up felt and temp fix on lead flashing until specialist is free. I got mine on ebay at good price. Always my go to product now. Evercryl | Roofing Repair Products & Compounds UK | Everbuild

 

[niall Y]

Would a bitumen roofing paint be the best bet for roof like this? Relatively cheap and waterproof.

 

[Jameshow]

I used Johnson floor paint from b+m at £25 for 5l was pretty good value tough as anything. I used it on a canoe too!!

 

[Spectric]

On galvanised metal you may need an etching primer.

 

[Bingy man]

A good few years back when I worked on site ( a prison ) the painters used something called calcium plumbate . It was extremely effective and normal paint was used over it - had a slight yellow colour to it and a 1 litre tin was quite heavy. Probably banned by the h/s squad but it was proppa good . Cost wise as with everything else the prices have gone through the roof ( sorry ) so it won’t be cheap for an area that size .

 

[scodiy]

I use this product- EVERBUILD GREY EVERCRYL ONE COAT. Years ago it was something called Fillcoat, very pungent! Patched up felt and temp fix on lead flashing until specialist is free. I got mine on ebay at good price. Always my go to product now. Evercryl | Roofing Repair Products & Compounds UK | Everbuild

Thanks for the suggestion. The coverage data suggests I'd need at least 13 cans though! Might not be cost-effective, but appreciate your reply.

 

[scodiy]

Would a bitumen roofing paint be the best bet for roof like this? Relatively cheap and waterproof.

I did think of that but bitumen isn't the nicest to use. It's also black, so would make the inside even hotter in summer. Thanks for the suggestion though.

 

[scodiy]

On galvanised metal you may need an etching primer.

I did wonder about that, although it's becoming more rust with every year that passes.

 

[scodiy]

A good few years back when I worked on site ( a prison ) the painters used something called calcium plumbate . It was extremely effective and normal paint was used over it - had a slight yellow colour to it and a 1 litre tin was quite heavy. Probably banned by the h/s squad but it was proppa good . Cost wise as with everything else the prices have gone through the roof ( sorry ) so it won’t be cheap for an area that size .

That definitely sounds like a lead paint, so I'll pass on that I think! Thanks for the suggestion though.

 

[Jaydee]

Might be time for a new roof?

 

[Herr Nilsson]

Jotamstic 90 GF by Jotun

https://www.jotun.com/ww-en/industries/products/Jotamastic-90-GF

 

[Henniep]

A good few years back when I worked on site ( a prison ) the painters used something called calcium plumbate . It was extremely effective and normal paint was used over it - had a slight yellow colour to it and a 1 litre tin was quite heavy. Probably banned by the h/s squad but it was proppa good . Cost wise as with everything else the prices have gone through the roof ( sorry ) so it won’t be cheap for an area that size .

Calcium plumbate was/is designed specifically for priming new galvanised sheeting, and bonds very very effectively to the galvanise. Once the sheeting has weathered and rusting, a single pack etching primer should do the trick. Top coat - most rubberised roof paints will do.

 

[highwood122]

Jotamstic 90 GF by Jotun

https://www.jotun.com/ww-en/industries/products/Jotamastic-90-GF

how many tins of that at £450 a go

 

[John Hall]

There are plenty of zinc galvanising paints out there that would make it look like new

 

[pauljhaigh58]

All Weather Roofing Compound Bitumen Waterproof Roof Coating 25 Litre https://amzn.eu/d/de632mr

 

[pauljhaigh58]

I used this it’s a cross between fibre glass and bitumen so does no crack
Paul

 

[Housey210]

Thanks for the suggestion. The coverage data suggests I'd need at least 13 cans though! Might not be cost-effective, but appreciate your reply.

What ever you do will cost money! Plenty of corrugated roofing sheets on facebook from £16 and film coated ones at £24. On top the fixings, sealants and flashings. Tough choice

 

[TomGW]

You will likely find that you have a supplier of profiled metal sheeting somewhere not too far away. Profiled sheeting is run off a roll of flat metal and is available in a range of colours finished in a plastic coating and both plain and non drip. Each profiled sheet covers 1m wide and can be ordered at your specific length, so no cutting involved.
There is one fairly close to us and last year I bought panels for a shed, black plastic coated, non-drip for £7/linear meter or sq m.
I would seriously consider that re-roofing is both cost and time effective in your case.

 

[JAW911]

Paint or etching primer won’t stop ck to galvanised metal. You need to apply T-Wash first then rinse it off with water. Once it’s gone black completely then you can paint it. Don’t use etching primer.