Is Pine Wood Waterproof?

Is Pine Wood Waterproof?

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If you are planning on building something for outdoor use, then it is of course vital that it is resistant to the elements. If you plan on using solid wood, you need to know that there are certain types of wood that are more waterproof than others.

Today, we want to find out just how resistant to the elements pine wood is. So, is pine wood waterproof or water-resistant? Let’s figure out if this wood is an ideal choice for outdoor applications.

Is Pine Naturally Waterproof?

Although pine wood may be relatively strong, looks nice, and smells even better, it is unfortunately not naturally waterproof. Pine is a softwood, and softwoods generally have grain structures that are not very tight. This wood also has fairly large pores.

At the same time, this material is also not very heavy or dense, plus it’s not very hard either. That lack of hardness, density, and its somewhat loose grain with large pores are all factors that add up, and unfortunately, it means that pine is not naturally waterproof.

In fact, this wood is not very water-resistant at all, and it’s not something that we recommend using outdoors. If you are going to use pine outdoors, you will absolutely need to treat it properly. This material is not naturally waterproof and it’s not something that deals with moisture very well.

Does Pine Absorb Moisture?

The unfortunate reality here is that yes pine does absorb moisture. In fact, as far as the different types of softwood go, pine is one of the worst on this front. This is just not something that you can use outdoors very well. If you use pine outdoors, and it has not been treated, it is going to start absorbing moisture over time.

Now, it is not the number one worst in terms of water resistance, but it’s certainly not one of the best either. If you try building something out of this wood, you don’t treat it properly, and it’s exposed to high levels of moisture on a constant basis, it is going to start to absorb water, and that is going to spell disaster over the long run.

Pine can absorb moisture, and this will lead to it getting even softer and weaker, it may start to rot and crumble over time, and it’s certainly going to lose structural integrity. It may then also develop mold and fungus.

Does Pine Rot When Wet?

If pine is able to absorb so much moisture, then it stands to reason that it will also start to rot if it is wet. Now, if you have old-growth pine, it may have some amount of rot resistance, although, for the most part, this is not a very rot-resistant type of wood.

If this wood absorbs too much water, it will begin to rot, and it won’t take very long either. If pine gets wet and does not dry out, you can expect that it will start to rot in just a couple of months. At the end of the day, it does not take very long for this wood to start to rot and decay if it is wet for a prolonged period of time.

Does Pine Expand When Wet?

Yes, when pine gets wet, it does tend to expand. This is simple science really because if a piece of wood absorbs water, that water needs somewhere to go. that water is going to get trapped within the fibers of the wood, therefore causing it to expand. Of course, this is not ideal at all, because anything structural in nature should be very stable.

If wood constantly contracts and expands with moisture, it’s not very stable, and can quickly lead to structural integrity issues. Pine will expand when it gets wet, and then contract when it dries out, which is a big problem. Wood that does this is not structurally sound, especially not over the long run. Once again, you really don’t want to use pine outdoors without properly treating it first.

Does Pine Warp When Wet?

Just like pine will expand and contract when wet, it will also warp. The more this wood gets wet and goes through the drying process, the more it will warp. Each time pine wood gets wet it warps a little more, and each time it dries out it warps even more again. This is not good in terms of overall durability or structural soundness, because warped wood is weak wood.

How to Waterproof Pine

As mentioned above, if you plan on using pine outdoors, you are going to need to waterproof it. Let’s just go through a quick step-by-step tutorial on how to waterproof this wood.

Step 1: Purchase Your Sealants

First, you will need to purchase an oil-based primer to get pine wood ready to receive the sealant. You will then also want to purchase a sealant. We recommend using an oil-based polyurethane sealant. These are very effective at keeping water out, form a durable surface, are cost-effective, and come in many different finishes.

Step 2: Prime the Pine

Using a paintbrush and your oil-based primer, prime the wood. Apply one layer on all surfaces and allow it to dry as the instructions indicate.

Step 3: Seal the Pine

Once your primer is totally dry, you can then apply a layer of your oil-based sealant. If you want to ensure that your pine is as waterproof as possible, you can always apply a second layer of the sealant, but just make sure that the first layer is totally dry before applying a second one.


The bottom line is that the pine is not very waterproof, but if you seal it properly, you can still use it for outdoor purposes.