When it comes to wood constructions around the house, most people consider plywood as the best option. This is justified considering that plywood is one of the most durable and stable wood types for building interior and exterior constructions for your home. However, how long does plywood last outside, and is it the best choice you have when it comes to exterior constructions?
Plywood is characterized by great durability, but how long exactly a plywood will last outside depends on several factors. Usually, the average life expectancy of exterior plywood constructions is around 35 years if everything is finished properly, but sometimes it can also reach up to 50 years.
Determining the type of wood for your exterior home constructions can be difficult since there are many choices on the market. If you have been thinking about plywood, then this article is definitely something you need to read before making your decision. Here, I will discuss plywood’s life expectancy and all its features and properties, so you can make a well-formed decision and not regret it later.
How Long Does Plywood Last Outside?
People tend to choose plywood whenever they have to build something for their exterior home space, such as a wooden deck or a roof sheathing. Plywood is one of the best wood types for exterior constructions considering it is pretty durable and its life expectancy is on a significantly admirable level. However, some people still have doubts when it comes to choosing the type of wood they will use because they do not know a lot about the features of plywood.
The first question that arises when choosing the type of wood for building different kinds of constructions outside is its life expectancy. Considering that the wood constructions you will make outside will constantly be exposed to various weather conditions and atmospheric changes, you need something that will last long. Also, you need a type of wood that will have the properties to withstand all these changes and conditions and keep its shape and look for a long time.
However, determining the life expectancy of any type of wood can be pretty difficult or almost impossible. The life expectancy of any kind of wood depends on the materials of which it consists, the way it has been installed, the manner in which it has been finished, and the environment in which this wood is set up. There are a few averages estimated for the life expectancy of plywood. Still, they depend on different factors, so it is never possible to determine for sure.
There are different types of plywood, and each of them is used for various purposes; therefore, the life expectancy differs in those terms. For instance, plywood used for siding can last for about 35 years if everything is installed and finished correctly. However, there have been cases in which plywood sidings have reached up to 50 years of life expectancy.
Plywood used for roof sheathing can generally last around 30 or 40 years, but again, you have to consider other factors, like the environment and the weather to which the plywood is exposed. Also, you have to think about the proper ways of maintenance of plywood if you want it to reach its years of life expectancy. You should not expect that plywood would always look like the first time you installed it if you do not take proper care of it.
If you have some plywood furniture inside, you may have noticed that this type of wood is significantly durable and can last forever. However, that does not apply to plywood used outside since it is exposed to many outdoor factors. Therefore, plywood used for interior constructions should not be maintained or chosen in the same way as plywood for exterior ones.
For instance, while the interior plywood might need more care related to the paint used on it, exterior plywood would require the durability of the type itself. In other words, when you choose exterior plywood, you would have to look into its durability properties. In contrast, for interior plywood, you would have to consider the features about the sustainability of paint and similar things.
Therefore, when you are about to do some construction outside, you would have to look into the factors that determine the life expectancy of plywood and the types of plywood that can be used for exterior building.
Which Factors Determine The Life Expectancy Of Plywood?
If you want to build something outside that will last for quite a long time, you have to consider a few factors before making a choice. These factors include the quality of the plywood, moisture absorption, and chemicals used for maintenance and treatment.
Quality
The quality of the plywood might be the most important factor in determining the lifespan of the wood. If you choose the plywood manufacturer carefully, and you know that this manufacturer is known for high-quality plywood, then you can expect that the wood you will choose will last for a long time, even longer than the determined life expectancy. On the other hand, if you choose something cheap from a discount store, you should not expect that the plywood will behave in the way you expect.
Usually, plywood bought from cheap stores and big-box home improvement centers is not characterized by high quality, and its lifespan is not as long as the store clerks might say it over there. Therefore, before making a choice, make sure that you do good research about plywood manufacturers. When you purchase plywood from high-quality manufacturers, you will know that your constructions outside will be in good condition for a long time.
Plywood bought from discount stores usually includes voids in the inner veneers. These voids contribute to life delamination of the plywood quite soon. They are the main reason for plywood losing its durability, and they generally lead to moisture absorption and damage of the plywood fast.
Moisture
Moisture is generally the biggest enemy of any type of wood. Usually, plywood in places that are exposed to moisture most of the time does not last long. That is why it is essential to carefully choose the type of plywood you will use for construction outside. In these cases, you have to select plywood that has a high level of water repellency.
Water repellency will help the plywood to resist moisture longer and achieve its lifespan to the fullest. However, it would be best if you did not confuse moisture with direct contact with water. When plywood comes with direct contact with water, then it might be fully damaged, while moisture would cause some slight harmful effects on the surface.
Therefore, your construction needs to be correctly installed and finished to avoid plywood getting in touch with water. That way, you will know that your outside constructions will resist weather and atmospheric changes. In other words, the proper installation will help plywood to last longer and reach its life expectancy.
Chemicals Used For Maintenance And Treatment
You need to consider the chemicals used in plywood since all plywood products are engineered wood products. That means that they all go through a particular type of treatment during the manufacturing in which different chemicals are used. These chemicals play a crucial role in determining the properties and features of plywood products.
In other words, these chemicals are a significant factor in determining the life expectancy of plywood. So, when buying plywood products, you need to check the chemicals that are used in the process of treatment. That way you will know whether the plywood you will buy will last as long as it is supposed to for outside constructions.
What Type Of Plywood Can Be Used For Outside Constructions?
Firstly, you have to understand and remember that not all plywood products are suitable for building constructions that will be exposed to different weather changes. That is why there is a distinction between interior and exterior plywood products. So, to pick the right type of plywood, you have to know the features and properties of each type.
What Is The Difference Between Interior And Exterior Plywood?
Interior plywood is mainly used for cabinets and different types of furniture, meaning that its appearance is more important than its resistance to rot and moisture. Therefore, while interior plywood has a good look, the exterior one is not so pretty due to many visible knots and blemishes. In addition, the exterior plywood is usually made of not so expensive hardwood, but it is quite durable and resistant to weather changes and atmospheric occurrences.
However, exterior plywood is not put in visible places on the constructions, so you should not worry about its look. It serves to make the structures stable and firm, but you can apply paint on them if necessary. On the other hand, interior plywood is way more pretty than the exterior. It is always suitable for paint application since it is mainly put on visible spots.
Types of Exterior Plywood
There are different types of plywood that can be used for outside constructions. However, you need to familiarize yourself with their features, so you can pick the one that will work the best for your structures outside.
CDX
CDX is the most common type of plywood used for exterior constructions. It comes in three levels of thickness, and the X in the name stands for exterior use, i.e. it gives you notice that you can freely use it on outdoor constructions. The C and D stand for construction grade, meaning that it is a firm type of plywood that will allow the building of firm and stable constructions.
CDX is the most common plywood grade; however, you can find better grades if you can afford to spend more money. In addition, you should know that with this type of plywood, you will never be wrong about life expectancy and durability.
Marine-grade
Marine-grade plywood is another type that you can use for exterior constructions. This type is quite similar to CDX, but it does not include sheets with knots; therefore, it is better for eliminating the formation of water pockets in your construction. It is also made of hardwood, and it guarantees excellent durability.
Marine-grade plywood can also be used for indoor constructions since it includes prettier looks. If you decide to use it outside, you will have to use some weather-protectant finish in order to protect your constructions from weather changes. This type of plywood can look great on wood decks in front of your house.
Also, marine-grade plywood is generally easy for installing and maintaining, so you will not need many tools and equipment to keep the plywood in good condition. Many people tend to use marine-grade plywood since it has great features and guarantees a long life expectancy.
Pressure-treated
Pressure-treated plywood is excellent for constructions that are exposed to extreme and severe weather changes. It usually comes with an oily surface, and the chemicals used in the treatments are aimed to contribute to the resistance of mold and mildew. However, the chemicals are known to be harm-free, so you should not worry about any harmful effects.
It is also known that pressure-treated plywood works great on outside constructions, and you do not usually need any special finishes to make the wood resistant to weather changes. Usually, the life expectancy is up to 30 years, or sometimes even more, depending on the way of installation.
To conclude, the life expectancy of plywood used for outside constructions is around 30 to 40 years; however, you need to know its features in order to make a good decision when choosing the suitable type of plywood. Also, you need to pay attention to the process of installation and finishing, so your plywood would last as long as possible.
Sources:
http://theplywood.com/lifespan
https://www.hunker.com/13401518/what-types-of-plywood-can-be-used-outdoors