People often assume that epoxy is perfect for use outdoors because it’s waterproof and hard wearing, but it’s not as simple as that. There are a lot of potential issues caused by exposure to sunlight and, in a lot of cases, you should consider alternatives.
This article will tell you everything you need to know about using epoxy outdoors and what the potential drawbacks are.
Table of Contents
- What is Epoxy?
- Is Epoxy Designed for Outdoor Use?
- Is Epoxy UV Resistant?
- Can You Buy UV Resistant Epoxy?
- Can You Use Epoxy as Outdoor Flooring?
- Can You Use Epoxy on Outdoor Wood?
- Can You Apply Epoxy on Composite Decking?
- Can You Use Epoxy on Outdoor Concrete?
- Can You Use Epoxy on Your Outdoor Driveway?
- Can You Use Epoxy on Your Roof?
- What Happens to Epoxy When Used Outside?
- The Verdict – Should You Use Epoxy Outdoors?
What is Epoxy?
Epoxy is a material made up of two components, a resin and a hardener. When mixed together, these two substances form a strong bond that can be used for a variety of purposes, from coating floors to sealing cracks. It is a polymer that can be molded and shaped into various forms, making it a versatile material for many different projects.
Epoxy is often used in construction and repair projects due to its strong bonding properties. It can be used to repair cracks in concrete, glue wood together, and even coat metal to prevent rusting.
Is Epoxy Designed for Outdoor Use?
Epoxy can be used for outdoor applications, but it is not always the most suitable option. In some ways, it is brilliant because it’s very water-resistant and it’s also very durable. So, it will give you a long-lasting coating that stands up to the rain. However, you may run into issues with UV rays. Although there are ways around this, it is common for epoxy to turn a yellowy color when exposed to the sun.
If you want to use epoxy outdoors, you may need to include certain additives and use a top coat of polyurethane to protect it.
Is Epoxy UV Resistant?
No, on its own, epoxy is not UV resistant. When exposed to sunlight, it can yellow, fade, and become brittle. However, there are specialist options available.
Yes, you can buy UV resistant epoxy that is designed for use outdoors. This includes additives to protect against the effects of sunlight and stop yellowing. The UV inhibitors absorb the rays and stop them from acting on the epoxy. However, these are not a permanent solution. Over time, the UV rays will still damage the epoxy.
Using a darker color of epoxy can make the yellowing less noticeable, but it will eventually become a problem. The best way to get around this is by using a top coat of polyurethane. This is a coating that is UV resistant, so it will protect the epoxy underneath and make it last a lot longer. The epoxy will still eventually turn yellow but if you use a combination of UV inhibitors and polyurethane, it will last for years to come.
Can You Use Epoxy as Outdoor Flooring?
Yes, epoxy has become a very popular choice for outdoor flooring in recent years. It is strong and durable, so it can withstand the elements, it’s cost-effective, and it is easily colored so you can fit it with the design of your home. The UV inhibitors that are used in outdoor epoxy products have come on a long way, so there are some great options for outdoor flooring available.
Epoxy is often used for concrete resurfacing in areas like patios. If the old concrete is weathered and needs to be revitalized, a layer of epoxy over the top can do wonders.
Can You Use Epoxy on Outdoor Wood?
Yes, epoxy can be used on outdoor wood. It is a great way to protect the wood from moisture and prevent rotting. This is particularly effective for protecting wooden patios and decking as well as any outdoor furniture. Although stains and paint are good for protecting wood, an epoxy coating can keep it good condition for much longer, so you don’t need to worry about treating the wood every year.
When using epoxy on outdoor wood, you need to make sure that the surface is clean and smooth before you start. Any roughness will show through once the epoxy has been applied, so it’s important to get it right from the start. Bear in mind that the natural wood will show through the clear epoxy, so make sure that it is clean. You can also apply stain beforehand if you want to.
Once the surface is prepared, you can apply the epoxy in a thin layer and leave it to dry. You will also need to use a UV resistant clear coat over the top to prevent yellowing.
Can You Apply Epoxy on Composite Decking?
Yes, you can use epoxy on composite decking. In fact, it can be a great way to protect the deck and keep it looking good for longer. Composite decking is made from a mix of wood and plastic, so it is more resistant to moisture, but it can still get damaged over time.
An epoxy coating will provide an extra layer of protection against the elements and any wear and tear. It is important to prepare the surface well before you start, so that the epoxy can adhere properly. Once it is applied, you need to leave it to dry completely before walking on it. Again, you need a UV resistant top layer because fading due to sunlight is one of the more common problems with composite decking.
Can You Use Epoxy on Outdoor Concrete?
Yes, epoxy is a brilliant way to resurface outdoor concrete. If you have a concrete patio area that needs to be protected from moisture, you could use a sealer or paint it. However, an epoxy coating will last much longer, as long as you apply it properly with a good top coat.
Can You Use Epoxy on Your Outdoor Driveway?
Yes, epoxy is good for driveways because it not only protects against moisture but it is also stain resistant, so you don’t need to worry about oil stains. You can find specific epoxy products designed for concrete and asphalt, which covers most driveways. Sealing your driveway will make it last a lot longer and avoid problems with weathering.
Can You Use Epoxy on Your Roof?
Protecting your roof from moisture is crucial. Any small cracks and gaps can let rainwater through and when that water starts leaking into the rest of the house, it cause a lot of expensive problems. There are epoxy products that are advertised to help you protect their roof but you should approach these with caution. Epoxy is a very rigid material, which is the opposite of what you need when trying to bridge cracks on a roof.
Polyurethane or acrylic coatings are usually better suited to rooftops and you can buy specific crack bridging products. These more flexible materials allow you to get on the roof and work up there without cracking under your weight. They are also less prone to yellowing than epoxy.
What Happens to Epoxy When Used Outside?
Epoxy on its own is not best suited to outdoor use. It has no trouble with moisture as it is waterproof but the UV rays do a lot of damage. When exposed to sunlight for an extended period, epoxy will turn yellow and eventually go chalky. Once this happens, it will start to degrade and you won’t have the same layer of protection that you want from it.
There are UV resistant epoxy products for sale and the technology here has been improving over the last few years. However, it’s important to note that they delay the damage caused by UV rays, but they don’t prevent it entirely. Some of the UV-resistant products are not very effective at all, so make sure to do your research and check online reviews etc, so you can get an idea of how they perform over time.
The Verdict – Should You Use Epoxy Outdoors?
This is a tough one because epoxy does have a lot of great benefits outdoors. It’s incredibly durable and water resistant, so it gives a better protective coating than most other options. But what about the UV issue?
Buying UV resistant epoxy and using a clear coat on top can prevent the yellowing, sometimes for years, but it will not stop it altogether. Theoretically, if you keep reapplying the topcoat every year or two, you can keep the yellowing at bay for longer, but it’s still not a perfect solution.
Overall, I would recommend using epoxy outdoors as a short-term solution. If you have a weathered deck or patio, for example, and you want to get a few more years out of it before you replace it, epoxy is a good choice. However, you don’t want to apply it over a brand new deck or some nice new wooden furniture because you could be shortening its lifespan by creating a problem with yellowing.
In most cases, you can find other alternatives that are UV resistant, so always explore your options before using epoxy for outdoor projects.
Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.