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Can MDF Be Used On The Exterior? How To Use MDF Outside

Wood has been used for construction for a long time, but modern methods now include the use of medium-density fiberboard (MDF) as an alternative. Can you use MDF outdoors?

Can MDF Be Used On The Exterior?

Yep you can use MDF outdoors if you treat it with the right stuff to keep it from getting damaged by moisture. You can also use MR MDF which is already pre-treated.

MDF And Exterior Use: A Brief Overview

Surprisingly, yes, you can use MDF outside and it has many advantages when used outdoors.

It’s also easy to work with, making it an ideal choice for projects like outdoor furniture and siding.

It’s key to understand the advantages of using MDF for outdoor purposes, so let’s get clear on what it is: MDF stands for medium-density fiberboard and is made from recycled wood fibers and binders.

As a result, it’s very dense, strong, and durable compared to other types of wood products. However, precautions should be taken if MDF is likely to be exposed to water. 

Precautions Needed 

The first precaution is to seal the MDF properly before exposing it to moisture. Sealing prevents water from penetrating into the wood and causing damage.

For outdoor projects, use a high-grade sealer specifically designed for exterior use. This will provide maximum protection against water and weathering.

The second precaution is to avoid direct contact with water for extended periods of time. If MDF does get wet, make sure it dries quickly by using fans or blowers to circulate air around the surface.

If not dried quickly enough, rot may begin to occur, which can lead to warping and structural damage over time, which in turn may be costly to you to fix!

For outdoor use, MDF should be okay as long as you take the necessary precautions. But it’s still best to protect it from too much moisture whenever you can.

Is MDF Ruined If It Gets Wet?

What if, despite your best efforts, your MDF gets wet? MDF is like a sponge – when it gets wet, it soaks up the moisture and swells.

This swelling can cause warping, bending, and even complete failure of the MDF material. 

MDF products can easily be damaged by water because they’re constantly exposed to the elements.

Rain, snow, and high humidity can all wreak havoc on the material if it isn’t sealed or protected.

The amount of damage done by water exposure depends on how long the MDF has been wet and how much moisture has been absorbed, but in some cases, it can be saved – hurrah!

Can MDF Be Used On The Exterior?

Steps To Take When MDF Gets Wet

If your MDF gets wet, it’s important to work fast and take the proper steps to prevent further damage.

The first step is to remove the wet MDF from its environment as soon as possible. This will help minimize water absorption and potential warping or swelling of the material.

If the MDF is attached to a structure, carefully detach it before moving it indoors.

Once the MDF is in a dry environment, let it air-dry completely before attempting any repairs. Depending on the degree of saturation, this could take several days.

If necessary, you can use fans to aid in drying out the material.

After the MDF has dried thoroughly, assess any damage that may have occurred and repair accordingly.

You may need to sand down affected areas or replace pieces entirely, depending on severity of damage. This may seem like a lot of hassle, so is there an alternative? Thankfully there is!


If you don’t want to add extra products to make your MDF moisture resistant, you can buy it pre-sealed using MR MDF.

MR MDF is a type of Medium Density Fiberboard, made up of wood fibers and resin, but that has been treated with moisture resistant properties. 

MDF, when compared to regular MDF, is much denser and more durable. It is an ideal choice for projects that require a lot of strength and resistance to damage.

MR MDF is also much easier to work with, as it does not splinter or warp as easily. You can create a variety of looks and it’s great for making decorative items and intricate designs.

MR MDF is a great pick for woodworking projects that need protection from the elements and won’t break the bank. Plus, it’s eco-friendly!

This material is perfect for DIY projects. It’s easy to work with, and you can give it the look you want with a bit of painting, staining, or varnishing.

Summary/Steps To Take If Using MDF Outside 

If you choose to take care of your MDF yourself, there are ways you can help make it last longer outdoors. In short, do your best to keep it safe by:

1. UV Protection. MR MDF needs protection from UV light if you’re using it in direct sunlight. An oil or lacquer finish can provide this protection and keep the material looking good for longer.

2. Moisture Resistance. Although MR MDF is more resistant to moisture than regular MDF, it is still not waterproof so you should treat it with sealant or water-repellent before being used outside.

3. Weatherproofing. Treat all MR MDF with a weatherproof coat such as paint or varnish to protect it from wind and rain damage. This will help ensure that your exterior project lasts for many years.


If you’re a keen DIY enthusiast and need some tips on using MDF or similar products, you’ve come to the right place.

To wrap up, Medium Density Fiberboard (MDF) or Moisture Resistant MDF (MR MDF) can be used for the exterior.

However, it’s important to take preventative measures to maintain its quality. 

If you need to use MDF outdoors, the best option is Moisture Resistant MDF. To protect it, you should seal it with a waterproof sealant. Happy DIYing!

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