Using Water-Based Paint Outside

Updated Jun 6, 2024 | Posted Oct 11, 2023 | Professional insight, Product Advice | 1 comment

The Decorating industry is slowly switching from oil- to water-based paint products. However, even a lot of Professional Decorators are apprehensive about this, especially when using water-based paint outside.

I’ve been a Professional Decorator for the past twenty odd years, and in that time, I’ve seen paint change dramatically. When I started out, no one would dream of using water-based paint on wood. The products available even a few years ago just weren’t good enough.

Things are different now. Manufacturers have found themselves competing to develop the best products they can. Now a lot of water-based paint products perform brilliantly well.

In this blog I’m going to talk about the things you should consider when using water-based paint outside and recommend a couple of my favourite products. I hope you find it useful.

 

The Different Types of Water-Based Paint for Outside

 

Wood Paint

This could be eggshell, satinwood, or gloss, and usually comes as an undercoat and topcoat system. You might use it on doors, windows, or even a timber gate.

 

Metal Paint

A water-based metal paint needs to do a lot, simply because it must withstand corrosion. There are products out there that you can apply directly to metal, but I like to use a primer to ensure longevity.

 

Masonry Paint

You’d use this to paint stone and render on the outside of your home. It contains high levels of biocide to stop mould growth, so don’t be tempted to use it inside.

 

Multi Surface Paint

As technology has moved forward, multi-surface paints have got better and better. The idea is that you can use these products on just about anything, including masonry, uPVC, timber, and metal.

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Is water based exterior paint as good as oil-based?

 

Yes, in most cases, water-based exterior paint is as good or better than oil-based. This is because water-based has superior flexibility, so it will cope better with expanding and contracting surfaces. Water-based is also more breathable than oil-based in some cases.

The only time I think oil-based exterior paint outperforms water-based is when using it in a high gloss finish. Water-based just doesn’t achieve the same sheen level as oil and can look rather cheap.

The best advice I can give you is to make sure you choose a good quality trade paint, whether it be water- or oil-based. Not just because of the initial finish, but exterior paints are tasked with protecting your house from the elements, which is quite an important job. Also, using good quality paint products will mean you don’t need to repaint as often.

Using Water-Based Paint Outside

Mike Cupit talks about the things you should consider when using water-based paint outside.

Using a Water-Based Undercoat

 

As explained in the video above, most water-based systems designed for use outside do not contain rust inhibitors or mould blockers. As a Professional Decorator, I have learnt that this can be a major issue when using water-based paint outside. There is nothing worse than rust patches bleeding through a painted surface a few weeks after finishing a job.

There are a few solutions; you could go for Bradite One Can, which is a multi-surface paint that blocks rust and stains. You could use Zinsser BIN Aqua, that blocks stains and sap bleed. But the product I’m going to put forward is Bedec All Prime.

This is a water-based adhesion primer that will block stains, rust, sap bleed, and can be used as a base coat when painting wood or metal. I’ll often use this under wood paint systems or multi surface paints.

Bedec All Prime is reasonably priced, available in white or grey, and it’s a product I have absolute faith in. It’s like a safety net, ensuring my paint system will last.

Bedec All Prime Water-Based Primer and Undercoat

The Best Exterior Water-Based Gloss

There is only really one water-based gloss that I’ve used outside and been happy with, and that’s Dulux Trade Quick Dry Weathershield. It’s an undercoat and topcoat system, but it usually takes three coats to cover a surface.

You’ll find it easy to use and it doesn’t look cheap and stringy like some of its competitors. It’s available in loads of different colours too. You might want to apply it with a mini roller and lay-off with a brush when using it on a front door.

This is a good paint, but the sheen level isn’t as spectacular as its oil-based counterparts.

The best water-based gloss for a front door
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The Best Water-Based Multi-Surface Paint for Exterior Painting

 

There are a lot of multi-surface paint products available now, but you shouldn’t rush into buying the first one you see.

After all, you’re asking one paint to cope with adhesion, durability, opacity, flexibility, and UV radiation. So, if you go for a generic or cheap paint, then the chances are it isn’t going to last very long outside.

There are a couple of good trade options available, but for me, the best in my opinion Zinsser Allcoat. You can buy this paint as an oil- or water-based, but the water-based version is far superior in my opinion. It’s available in matt, satin, or gloss finishes, it’s self-undercoating, easy to use, and you’ll achieve a great finish with it.

I love Zinsser Allcoat; It’s one of the best water-based paint products you can use outside and it’s very capable on loads of different substrates.

It’s just so easy to use, and it seems to last for years without so much as losing its colour (unlike some other water-based paints).

One thing I will say about Zinsser Allcoat, is that although you can apply multiple coats in a day, it does take a couple of days to harden and fully cure. So, if you’re using it on front doors or outside windows, leave them open as long as you can before closing them.

The Best Water-Based Masonry Paint

 

Most exterior walls are render or some other type of masonry, so you need a masonry paint to coat them (some people call me ‘Captain Obvious’). Water-based masonry paint is the best bet unless you’re painting in challenging weather conditions, in which case, you’d opt for pliolite-based.

There are loads of good water-based paints for exterior walls, but I’ll give you my preferred products.

Dulux Trade Weathershield

This is one of the most popular water-based masonry paints on the market. It’s loaded with polymer binders, has great opacity, great adhesion, and is easy to use. You can buy it in just about any colour too. I have used loads of Dulux Weathershield over the years, and I’ve always found it a quality product at a reasonable price.

If you’re going to opt for this paint, make sure you get the ‘trade’ version, because it is a lot better than its retail counterpart.

Emperor Masonry Paint

Dulux Weathershield may be a good product, but Emperor Masonry paint is another level, and probably is the very best water-based paint for exterior walls. (although you do pay a premium price for it). Rather than polymer, Emperor use silicon in their water-based paint, meaning it is water repellent and very breathable.

This has a few benefits; it never traps moisture into your walls, so generally lasts longer, and because it’s water-repellent, it is more likely to stay clean. Any muddy marks are generally washed away the next time you get a heavy downpour. Plus, it has a longer life expectancy, meaning less decorating.

If you do buy this paint, we have secured a coupon code. Use ‘DFUK’ at the checkout.

FAQs

 

What Happens if you use Interior Paint Outdoors?

Interior paint is often cheaper than exterior paint, and depending on the product, may be ok to use outdoors. I’d advise against it though! Trying to save money on paint for outside is false economy.

Interior paints are not designed to cope with the challenging environment outside your home. They won’t expand and contract on timber surfaces, so end up peeling. Or UV radiation can quickly cause them to fade.

This will lead you to needing to redecorate sooner than you would do otherwise, costing more time and money.

 

Is Water-Based Paint Waterproof?

Yes, exterior water-based paints, durable emulsion paints, and trim paints are all waterproof once dry. However, you could go one further. There are some water-based exterior paints that are hydrophobic, which means they actually repel water. Click here for a full guide on water-based exterior paints.

What are the disadvantages of water-based paint outside?

I can only speak from my personal experience, but I’ve finished jobs with water-based paint, then drove past a few months later and noticed rust patches bleeding through. This happens a lot when painting soffit and fascia because it is held together with nails.

 

Can you use water-based paint in the rain?

I worked with a maintenance guy once who told me, “You should use water-based paint when it’s wet, because oil-based paint doesn’t stick”. Unfortunately, he was wrong. Water dilutes water-based paint, so if you use it in the rain, it’ll simply run off the surface and make a mess of the floor.

 

How long does water-based paint take to dry outside?

As water-based paint relies on evaporation to dry, the time it takes to set is highly dependant on the weather. However, most water-based paints in fair conditions are touch dry in an hour. It can take a couple of weeks to harden up and cure.

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Final Thoughts

 

I hope this has given you some insight about using water-based paint outside. Providing you use a good-quality product, you really don’t have anything to worry about. You’ll find water-based much quicker and easier to apply, it’s better for the environment, and easier to clean from your skin.

Happy decorating!

Updated Jun 6, 2024 | Posted Oct 11, 2023 | 1 comment

About the Author

About the Author

Mike Cupit has been in the decorating industry since 2002 and has mostly worked as a Trade Decorator in the domestic sector (peoples’ homes). Self-proclaimed “product geek”, Mike has a passion for paint and decorating tools. Mike now spends most of his time testing paint products and tools, comparing them to similar products on the market, and blogging about the industry in general.

1 Comment

  1. Richard

    While l like water based outside l find the oil based is just that bit tougher..

    Zinnser allcoat tends to pull off the previous sound well prepped coatings, had this on window cills.

    Its the same with water based woodstains externals they just are not as tough esp over old oil woodstain with major clean prep etc, doesnt stick the same l find. , l used both and find the oil far better whatever the brand.

    The new Bradite one can promises the earth and merchants sing praises but a painter l knew did lots drain covers well prepped and last year in the early dry summer its not even lasted a year.. Merchants advised to use for this..

    It would have been better with bog standard oil coloured leyland gloss !! Never mind excellent oil Dulux metalshield etc

    All needs redone because water based just does not last love it internal but serious doubts external

    Reply

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