best paint for corrugated metal roof UK

Best Paint for Corrugated Metal Roof UK (2021)

Last Updated on 23 September 2021

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Painting a metal roof is something you only want to do a couple of times in your life, at most, so it’s vitally important to pick the best metal paint. Fortunately for you, I’ve researched hundreds of paints for roofing projects over the years, so I know what a minefield it is and how to navigate it.

I’ve used this experience while researching the latest paint systems on the UK market. So read on to find which paint wins the ‘best paint for corrugated metal roof UK‘ award.

In a Hurry? Here’s our Top Pick for 2021:

Cladding Paint 10 litres | Wethertex CP80 Clad-Seal Steel & Cladding Coating | Assorted Colours RAL & BS (Black)
  • Cladding paint for weathered galvanised, Plastisol, powder coating, steel, tin, aluminium, copper, zinc, and lead
  • Can be applied by brush, roller or spray, with long-term colour retention
  • Available in white, black or a wide range of RAL and British Standard (BS) colours
  • Protects cladding for up to 12 years with its rust resistant finish
  • Impact resistant, self cleaning and suitable for multi substrates, offering ultimate performance

Last update on 2021-09-26 / Affiliate links / Images from Amazon Product Advertising API


What Makes a Good Roof Paint?

Having researched and procured metal roof paint products for many years, I discovered all the different types of paint available: acrylic, latex, alkyd, liquid rubber, polymeric, silicone. And then there are the hybrids.

It’s mind-boggling. Each one has its merits and downsides, and it’s challenging to determine what’s best for any given situation. I’ve chosen three products with different base chemicals for this guide, but each works well.

The best paint for corrugated metal roofs must have the following qualities:

  • Resistance to UV light
  • Elasticity to deal with extremes in temperature
  • A reasonable rate of coverage
  • Longevity – you don’t want to be up on that roof every few years
  • Anti-corrosion properties
  • High adhesion to smooth surfaces

If the roof is visible, colour choice is also a factor.


Methods of Application

man spraying red paint on metal roof
worker spray red color on roof steel for house construction

The three typical methods of application are roller, brush and spray gun.

1. Roller

Being corrugated or profiled, you need to roll across the slope unless you have access to a profile roller – a roller shaped to match the corrugation or cladding profile. A short nap roller provides the best finish.

2. Brush

A brush gets into all those areas where a roller can’t reach, such as underneath flashings and ridge sections.

Pro Tip: If the roof is pretty flat, you could use a soft yard brush to spread the paint across the surface quickly.

3. Spray Gun

The most effective method is to use a spray gun. There are two types of spray, air and airless. In simple terms, air sprays need a compressor, which can be heavy and bulky – not something you would want to haul up onto a roof.

Airless sprayers pump the paint directly from the can or a container attached to the spray gun.

Spraying is the quickest method and provides the neatest finish if used correctly. The downside is cost. Spray guns and compressors aren’t cheap, but you can hire them.

Whichever method you choose, bear in mind that the areas of coverage quoted in this guide are for flat surface areas. So the actual surface area is much less, depending on the depth of corrugation or profile.

Pro Tip: Allow 25-30% extra for profile depth when pricing or ordering paint.


Best Paint for Corrugated Metal Roof UK – The Top 3

So, let’s take a look at our top picks for corrugated metal roof paint.

#1: Wethertex CP80 Clad-Seal Steel & Cladding Coating

Cladding Paint 10 litres | Wethertex CP80 Clad-Seal Steel & Cladding Coating | Assorted Colours RAL & BS (Black)
  • Cladding paint for weathered galvanised, Plastisol, powder coating, steel, tin, aluminium, copper, zinc, and lead
  • Can be applied by brush, roller or spray, with long-term colour retention
  • Available in white, black or a wide range of RAL and British Standard (BS) colours
  • Protects cladding for up to 12 years with its rust resistant finish
  • Impact resistant, self cleaning and suitable for multi substrates, offering ultimate performance

Last update on 2021-09-26 / Affiliate links / Images from Amazon Product Advertising API

Wethertex CP80 is a high-performance, self-priming paint. It’s quick-drying, meaning you can apply a second coat after only 2-4 hours. 

CP80 is available in a wide choice of standard colours, which you can tint with any RAL or BS4800 colour. With over 4,000 colours to choose from, it’s excellent when matching an existing colour, and CP80 dries to a highly water-resistant satin finish.

The 10-litre tubs are on the heavy side (about 13kg), so you may want to decant half of this into a smaller container to carry onto the roof, especially if you need to thin it down. CP80 should be thinned with 10% water when applied to bare metal surfaces, which improves the 10 m2/litre coverage rate even further.

CP80 can be applied using a brush, roller or spray, but take note of the weather conditions at the time. Don’t apply in cold or hot weather (less than 8°C or more than 25°C) or when the substrate temperature is over 30°C. Check the forecast for rain as well, as it needs to remain dry for at least 24 hours.

Avoid sunny days – dry but overcast is ideal, so a typical UK summer’s day is the best time.

CP80 offers excellent protection against rust for up to 12 years, and it’s also resistant to salt spray, making it good for coastal regions. It’s suitable for use on all roofing materials, including weathered galvanised steel, Plastisol, PVF2 and powder-coated steel, aluminium, copper and zinc

ProsCons
The coverage rate of 10 m2/litre is the best we foundIt can’t apply in extreme temperatures or wet weather
12-year rust protection – also the bestRequires two coats
Quick-drying time 
No primer required 

#2: Rust-Oleum Mathys Metal Cladding Topcoat 

rust-oleum metal cladding topcoat 

https://www.rawlinspaints.com/home/cladding-paints/625-rust-oleum-mathys-metal-cladding-topcoat.html

This semi-gloss acrylic resin paint is specially formulated for use on all types of metal cladding with decent single-coat coverage of around 8 m2/litre. It has excellent UV resistance, a 10-year life expectancy and comes in an extensive range of RAL and BS4800 colours.

You can apply Rust-Oleum Topcoat to galvanised steel, aluminium, copper, zinc, and Plastisol coated sheeting, providing a long-lasting, durable finish. It’s not as quick-drying as Wethertex CP80, but you can apply a second coat after 8 hours.

Like Wethertex, the weather at the time of application is critical. Avoid hot or cold days, and don’t apply the paint if it looks like rain in the next 24 hours. You can use a brush, short nap roller, or airless spray gun to apply the paint. 

Pro Tip: When using a spray gun, one coat should do the job.

A 10-litre tub of Topcoat covers around 80 square metres, but you may also need a primer on some uncoated surfaces. We recommend Rust-Oleum’s water-based Mathys Metal Cladding Primer for this purpose. This primer is suitable for most metal roofing materials and is available in white, light grey, and dark grey. It’s ready for a topcoat in just one hour, and a 10-litre tub covers 125 square metres.

ProsCons
10-year life expectancyPrimer required on some surfaces
Low VOCIt can’t apply in extreme temperatures or wet weather
Quick-drying 

#3: Durashield Grey Rubber Based Waterproof Roof Paint

Durashield Grey Rubber Based Waterproof Roof Paint Coating Sealant 2X 5 Litre, High Performance One Coat System with a Longer Lasting Smooth Finish
  • A smooth, cold applied rubber based waterproofing topcoat for a longer lasting seamless coating
  • Ready to Use & Instantly Waterproofs Effected Area. Flexible elastomeric system. Primer not normally needed but please check with the manufacturer
  • Ready for use on EPDM rubber, flat roofs, weathered asphalt and bituminous surfaces, concrete, brickwork, fibreglass and GRP, weathered plys, OSB/plywood and wooden substrates.
  • One coat: minimum Coverage of 1m2 per Litre. Developed for single coat applications with 10 year life expectancy. Sheen and smooth finish
  • One coat: minimum Coverage of 1m2 per Litre. Developed for single coat applications with 10 year life expectancy. Sheen and smooth finish

Last update on 2021-09-26 / Affiliate links / Images from Amazon Product Advertising API

The previous paints are ideal for large roof areas. If you just want to give your garage’s corrugated metal roof a new lease of life, it’s worth considering this Durashield rubber-based paint.

You can apply Durashield flexible elastomeric system with a brush or roller, and in most cases, without a primer. Furthermore, this paint will give you up to 10 years of rust-free service.

Our British summers aren’t a problem either – you can apply durashield within a temperature range of 5-25°C, and it doesn’t matter if it rains soon after, as the rubber coating sheds water immediately.

Durashield is only available in grey, but this won’t be a problem if you’re not looking for colour.

Don’t be fooled by the low price, though. Durashield is rubber-based, so the coverage is much less than water-based paint; in fact, a small 3m x 6m garage needs five or six 5-litre tins.

ProsCons
10-year lifespanIt only comes in grey
Suitable for repairs as well as complete roof coveringExpensive for large areas
You can apply in damp conditions 
One coat should be enough for most jobs, and no primer is required. 

Best Paint for Corrugated Metal Roof UK – Comparison Table 

Product Cost/m2 Base Material 2nd coat (hours) Coverage (m2/litre) Longevity (years) Rating out of 5
Wethertex CP80££Silicone2-410124.8
Rust-Oleum£Acrylic88104.7
Durashield£££RubberNot required1104.2

Final Thoughts

Wethertex CP80 is the stand-out product in this comparison simply because it provides a 20% increase in longevity over its nearest rival, and when you’re doing any roof work, the less frequent, the better.

Rust-Oleum is an excellent product, and although it may need a primer, primer works out cheaper than the topcoat.

If you’re not concerned about colour and you don’t have a large area to cover, Durashield is worth considering, but beware of the low coverage rate – it could work out to be very expensive.If you want to know more about the different types of paint for metal roofs, Coatings.co.uk has produced a guide on their website, and although this refers to other paint, the principle is the same.