MDF or Medium Density Fiberboard is a popular choice for its versatility and low price. But it has some limitations too. So if you are thinking if you can make some outdoor furniture with MDF board, read this article first to find out what’s wrong with the idea.
Can MDF be used outdoors?
MDF board can’t be used outside as it has the least water-resistant capabilities. The biggest weakness of MDF boards is that water can deal irreversible damage to them. MDF board does best indoors where it does not have to be exposed to direct water or high humidity.
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Before jumping into the moisture or water-related disadvantage of the MDF board, let’s appreciate this fantastic find. It is a cheap and environment-friendly alternative to wood.
Although it is made of wood, practically, it helps to be less dependent on wood as it is produced with waste wood parts and recycled woods.
Water is the major problem of MDF boards. It does terribly in a damp condition. So, it’s the last wood product you will want to use outdoors.
MDF boards are pretty versatile, and you can make almost all types of furniture and decorations with MDF boards, but the only condition is you can’t leave them exposed to water. Not only outdoors, even not all the places in your house are suitable for MDF boards.
You can’t use MDF in your kitchen, bathroom and balconies.
However, some high-quality MDF boards have some sort of resistance against moisture. They will work in moderate moisture conditions, but direct water will damage the board.
There are also water-resistant MDF boards in the market, but they are not totally water-resistant. The board will get slow damage when exposed to the water.
Some companies claim that they have water-resistant MDF boards, but further research is needed to back up their claim.
Those variants of MDF boards are about twice the price of standard MDF boards. You will get a similar amount of plywood at the cost of high-quality MDF boards. MDF boards are not made to be water-resistant. It’s strong, cheap and easy to work with.
MDF is made of breaking down hard or soft wood, glue and chemicals. Wood absorbs water, but a small part of wood absorbs water more rapidly.
So when water comes into contact with the MDF board, the wood particles absorb water fast and become swollen and soft, which can not be recovered.
That does not mean the MDF board will be useless if it comes into contact with water. The damage depends on how frequently the board comes into contact with water and how long the board stays wet.
If an MDF board comes into frequent contact with water, the board will become damaged entirely within weeks or months. But there is a way to recover some damage if you take steps to dry a wet MDF board.
You can make wood weather-resistant by adding paints but does that work for MDF boards? Here’s the answer.
If painted:
Paint can add some sort of protection, but it can’t be a solution. Water will still leak inside the wood and break the structural bonds of MDF boards. You can paint your furniture as you wish, but you can’t expect to make it water-resistant and suitable for use outside by coloring it.
Is MDF suitable for outdoor use?
MDF is not suitable for outdoor use as the board will get damaged and become fragile within a short time. MDF can last at least 10 to 15 years, but a damp condition can reduce its life dramatically.
Why is outdoor not suitable for MDF boards? Even if it does not rain, morning due is enough to cause damage to MDF boards within a few months.
If your MDF furniture gets exposed to water, you can keep that in the outside sun but make sure to bring that back before night or rain. If you can keep your MDF furniture safe from moisture, the furniture will last many years and cost only half the price of plywood furniture.
There is also some furniture that is unsuitable for making with MDF boards. Such as, a dining table frequently comes into contact with water.
3 reasons why you cannot use MDF outdoors
MDF boards are one of the most cost-effective indoor furniture and decorations options. But why can it be used outside? Is there a way to use it outside? Read the following points.
It’s not meant to be used outside:
MDF is an engineered wood product that mainly focuses on making a cheaper alternative to wood and recycling the existing wood than cutting trees. But there are limitations.
Even if water-resistant MDF is possible to make, it will be costly like wood and there why the purpose of MDF boards is not being fulfilled.
It expands in water:
MDF boards absorb water like a sponge, and the wood particles swell up and become soft and lose their shape.
Moisture exposure dramatically reduces the life of MDF boards, and once the board is expanded and softened, there is no way to fix the damage. But the good thing is the expanding and weakening process does not happen overnight.
A thoroughly wet MDF can last if you can dry it fast.
Moisture reduces its life:
The environmental moisture is low and consistent indoors. MDF board strength and longevity highly depend on the humidity in the air.
On the outside, MDF boards will come into contact with due, rain and moisture, which drain life and strength out of MDF boards.
Can MDF get wet?
MDF can get wet and absorb a lot of water into it. The low weight makes it easier to work with and suitable for many furniture, which also means it can absorb more water inside. And the longer the board is wet, the sooner it will become fragile and useless.
If your MDF board gets wet, you should try to dry it as soon as possible. First, use a cloth to remove water and keep the board in the sun until it completely dries. Airflow can also help to dry an MDF. A hair dryer also does well to dry up a small area.
What happens to MDF if it gets wet outside?
MDF boards will become softer and expand by the moisture outdoors. The damaging process depends on the weather and the environmental conditions. But there is no easy way to avoid the damage.
First, MDF will come in contact with the morning dew outside. If it does not rain, you will not see much difference in the first few months.
But the upper layer will continuously absorb moisture from the environment, and after a few months, the board will begin to expand. The expanding process will damage the laminating part, and the inner materials will be exposed.
Then MDF will absorb moisture faster and become useless soon.
What is exterior grade MDF?
Some MDF companies introduced exterior grade MDF which they claim can be used for outdoor applications. Those MDF are made with high-quality materials and have some resistance against water, but as the board ages, it also becomes damaged.
They last longer than standard MDF boards, but they are also almost as expensive as regular wood. You can use some other cheaper options for exterior applications. So, the best thing is to use MDF indoors and look for a more reliable alternative to use outside.
How to seal MDF for outdoor use?
Sealing MDF is not an easy and reliable option most of the time. It’s the only disadvantage of using MDF, and no expert will recommend you to use MDF outside. But still, if you need to, here are some possible ways to use MDF outside.
Use MR MDF:
Moisture Resistant MDF can be an option where moisture is a concern. But note that it’s moisture-resistant but not water-resistant. That means those MDF can be used in the kitchen and balconies. But they can’t be used outdoors and in bathrooms.
Paint:
Waterproof paint will add a layer of protection, but that’s not a complete solution as you will have to paint the MDF frequently.
Polyurethane layer:
A polyurethane layer can save MDF for some time, but it’s also not a permanent solution.
Final Thoughts
It’s better not to use MDF outside as environmental moisture and rainwater can highly damage it. Soften and swelled up MDF is very weak, and even a kid can break it with a karate chop. There are some half solutions for using MDF outside, but none of them is convenient.