Leave Deck Untreated (What You Really Need to Know)

Decks are important places for gatherings and outdoor activities, especially during summer. Therefore, constructing a deck that can last for decades will definitely pay off to serve your recreational needs. You may wish to know whether your deck can remain intact even when you leave it untreated.

So, can I leave my deck untreated? An untreated deck can last a long time, depending on the timber used to build it. Even without regular deck maintenance and treatment, the deck can be used as it is, however, it may not last as long as a treated deck. Some types of timber like merbau timber can be a better option for decking if treatment is not planned as this timber is durable and can last up to over fifteen years, depending on the weather or season.

Most untreated wood decks can last approximately five to ten years unless they contact moisture and harsh weather. Nevertheless, using wood such as pine for an outdoor deck may be costly because it can easily rot with frequent moisture, making it prone to loosening and eventual breakage. With a lifespan of around two years, you may soon start thinking of a replacement.

However, any wood is at risk of destruction when you expose it to harsh environmental conditions. You may find painting and sealing the deck as an alternative to treating but exposing it to excess sun rays and rain will start to deplete and weaken your painting leaving the wood vulnerable to fungi. Therefore, it all depends on how well to preserve your deck.

We aim to help answer your questions about deck treatment and whether your deck can survive without it. We give you the tips you need to preserve your deck and the dos and don’ts to consider when you decide to leave your deck untreated.

How Do You Ensure That Your Untreated Wood Lasts Longer?

With a certain level of maintenance, your untreated deck can still survive for some more years. We compiled some effective methods tips that you can implement to ensure that your wood lasts longer, even without treating it.


Sun rays can destroy natural substances from the woods and cause them to bleach. Therefore, the best remedy would be to ensure that your deck has enough shade to shelter it away from direct sunlight. Once the natural chemicals in wood and oil are depleted, the wood will automatically be vulnerable to decay and rot. Hence, by all means, try to protect your deck from excess sunlight.

Wood Protection

The material you use for your deck is vital in determining its lifespan. For instance, hardwood is the best choice for your deck since it is more durable than the alternative softwood. However, note that using hardwood does not guarantee that your deck will outlive a treated deck, so you still need to protect it from decay by painting and sealing. Doing so prevents sun rays and will help repel water from the deck.

Choice of Wood

Your choice of wood is also important; different woods come with different life spans; therefore, your deck’s durability will depend on it. For instance, timber from trees such as cedar and redwood has a durability of more than fifteen years. These timbers may be costly but will serve you better than pinewood, which has a shorter lifespan of below ten years.

Keep the Deck Dry

Fungi thrive in moist places, and once there is enough moisture, they can easily attach themselves to wood and accelerate rotting. On the other hand, keeping the deck dry will deny them the moisture they need to survive, hindering their infestation. Therefore, it would help that your deck remains dry and the temperatures do not favor fungi survival; this will save it from decay.

Applying a Wood Sealant

A wood sealant will provide your deck with natural oil to protect it from moisture and sun rays that cause decay. You can use a sprayer pump to spray your deck and spread the sealant using a roller brush, ensuring that it fills all cracks on the deck. A well-spread sealant will not allow moisture penetration into the wood, for this can cause instant rot. Similarly, a clear wood sealant is a good option for your deck compared to a colored one since it doesn’t wear quickly.

Dos and Don’ts for Long Lasting Wood

As much as you strive hard to maintain your deck and protect it from decay, there are some procedures that you should avoid when caring for and maintaining your deck. The following are some dos and don’ts to assist you.


It is important to clean your deck at least once a year to help remove dirt and any developing fungi; this exfoliation procedure is particularly effective to employ during summer. For proper deck cleaning, we advise that you scrub it using a machine or sandpaper. Also, you may use a pressure washer for thorough cleaning. Afterward, you can paint the deck using oil-based paints or sealants.

Before you start the painting process, you need to be careful with any plants around the deck. Given that the sealants and cleaning substances contain hazardous chemicals, they may kill the plants. Another important factor to consider is to ensure that you periodically inspect the deck to check for any signs of damages. Be on the lookout for soft spots, loose nails, and splits or rotten wood. Once you notice unusual developments on your deck, it is appropriate to take action to repair them.

If you plan to seal your deck, you need to sand it since you may notice some wood patches after pressure washing thoroughly. Once the deck is dry, you can use an 80grit sander to create a fine deck surface; using a power sander may be quite destructive. However, if you have a lot of work to do on your deck, you can begin with a power sander and finalize with hand sandpaper.


Using paint as sealant may cost you because it can wear out, leaving your deck vulnerable to decay. You will have to sand your deck to eradicate the paint. We advocate for a synthetic sealant because it cannot easily wear and may help protect your wood from decay. There are also some semi-transparent sealants that you can use in case you need to add color to your wood.

Secondly, avoid cleaning your deck using a chlorine-based bleach substance since it can decolorize your deck, leaving it unattractive. The bleach can also interfere with the wood’s cell structure leaving it vulnerable to decay agents. We also advise that you don’t use a powered washer unless you are skilled enough to use it. Otherwise, you can call in an expert to assist if you still want to use a power washer.

Some people hold the washers unsteadily, making the deck look like beetles have attacked it. You can move the nozzle at an angle that can effectively sweep the wood particles from the surface easily; this may be approximately 9 inches to ensure that the nozzle doesn’t stand at one point.


Clearly, an untreated deck has a shorter lifespan than a treated deck. However, it can still serve your purpose, especially if you were building a temporary deck. The best way to ensure your deck’s durability is by treating it; however, it can still serve you even when you leave it untreated.

It would be best if you looked at certain factors before deciding whether to treat it or not. For instance, consider the weather and the type of wood your deck is made of. If you use hardwood for your deck, then it may last longer when untreated compared to softwood. Similarly, if you live in a place with harsh weather, your wood may be more prone to damage.

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