My family had a cabin near the ocean, and the entire structure apart from the roof was constructed from wood. I went outside to get some fresh air, and I saw the wood looked fuzzy. Concerned, I asked my father about it. He explained that it had been a while since they had maintained the cabin. It led me to wonder how do you protect wood from saltwater?
The best way to protect the wood from saltwater is using creosote or oil-based preservative on the wood before it comes into contact with saltwater. Because salt can penetrate deep into the wood, it needs to be treated before this happens, or it will keep on degrading even after using a preservative.
Wood has been used in construction for centuries and has been at the forefront of other household and industrial applications. I wanted to learn more about saltwater’s effects on wood and protect the wood from saltwater. I decided to share what I discovered.
What Does Salt Water Do To Wood
Before we dive into protecting the wood from salt water, we must know how saltwater affects wood. Wood has been used near and in saltwater for a long time, and the one thing that has been observed throughout the centuries is how saltwater affects wooden structures.
Different factors influence how wood gets damaged in saltwater. Here are some of those factors:
How The Type Of Wood Effects The Damage Of The Wood
The type of wood you use will also affect how saltwater damages it. Hardwoods like teak and Ipe are the best woods to use near saltwater.
They have a natural oil ingrained into the wood, which protects it from the saltwater and the organisms in saltwater that love to feast on wood. This oil makes teak the strongest and most durable wood in teak in any weather condition.
Untreated woods or woods treated with water-based preservatives have little to no real protection against saltwater and will start to degrade in as little as 5 years in regular wetting and drying cycles.
How Organisms In Salt Water Damage Wood
Saltwater contains tiny marine organisms that love to feed on wood. These organisms are also known as shipworm.
When untreated or improperly treated wood comes into contact with salt water, these organisms eat away at the wood where it touches the water. There is also the risk of termites, wood borers, and wood rot.
How Chemicals In Salt Water Damage Wood
Saltwater with sodium chloride present will leave a white powdery residue on the wood. The powdery substance is usually Chlorine. Over time the Chlorine will absorb into the wood and damage the lignin structure on the inside of the wood leading to the fuzzy hair-like surfaces on wood damaged by saltwater.
Experts suggest that the wood underneath is still safely protected. While this may be true, it is still in your best interest to protect the wood from all forms of decay saltwater exposure can cause. So when you see what looks like hair on wood, it needs to be treated before it degrades more.
How Do You Protect Wood From Salt Water?
When you live in a tropical or rainy climate, you want to keep your wooden structures as safe from water damage as possible. It is even more important when you live near saltwater. No matter what type of wood you use, eventually, you will need to treat it so it lasts longer.
The best time to treat the wood is from the beginning before it comes into contact with saltwater. Here are the best ways to protect the wood from saltwater.
Buying The Right Kind Of Wood
The first step in protecting wood from saltwater is to use the right wood; that way, it takes longer for the salt, chemicals, and organisms in the salt to damage the wood. Unfortunately, it is more expensive to buy woods that are naturally more resistant to saltwater degradation.
However, in the end, you won’t need to replace or rigorously maintain these more expensive woods like you would with cheaper or untreated woods. The best wood to use near salt or regular water is Teak or Ipe wood. The natural oil that these hardwoods have is the best protective barrier in wet conditions.
These hardwoods have a natural oily protector that helps protect the wood from water, salt and chemical degradation, insects and organisms, and wood rot.
Buying Kiln Dried Wood
When wood is dried in a kiln, it contracts the wood and closes pits in the wood. Wood then shrinks, and there is little to no space for water to accumulate immediately. It won’t last forever, and the wood will eventually need a preservative, but this is just one step closer to protecting the wood from saltwater damage.
Using The Right Preservative
When you need to use a preservative on wood that will protect against saltwater and last the longest, the best preservative to use is an oil-based preservative. There are a few oil-based preservatives on the market.
The wood preserving oils that protect the wood from saltwater penetrate deep into the grain of the wood and replace the natural oil the wood might have lost during exposure or drying.
This oil creates a barrier that helps the wood not absorb the water, or the salt, chemicals, and organisms in the saltwater won’t affect the wood as it does with untreated wood.
Creosote Oil-Preservative
Creosote Oil is an excellent wood preservative that comes from the distillation of coal tar when making steel. Coal tar is released from the coal during the coking process using high oven heat.
Creosoting is when vacuum and pressure are used to impregnate the hot creosote oil into the wood. This process can only be done in an industrial setting as there are regulations in place that prohibit the use of creosote wood in places like:
- Playgrounds
- Gardens
- Inside buildings
- Inside toys
The regulations passed in 2003 help keep people and animals safe from the accidental consummation of the creosote. So using wood that has been treated with creosote will help in a saltwater setting, and you can buy them pre-treated.
The estimated life expectancy for wood treated with creosote is 40-80 years. There are DIY creosote products on the market that you can buy at most hardware stores, but they don’t have the same strength or staying power that the professionally pre-treated wood you buy has.
Teak Oil Wood Preservative
Teak oil is the best preservative to use when dealing with regular exposure to saltwater. It’s a natural wood oil that penetrates deep into the grain of the wood, seals off the wood from water damage, wood rot, fungal and insect invasion.
You need to apply a coat and remove the excess oil before it dries, then you need to apply a new coat after 24 hours and repeat this process until the wood is saturated with the oil. You then wipe the excess off and leave it to dry completely. You should repeat this process at least twice a year.
Hard Wax Wood Oil-Preservative
Hard Wax oils are considered a mix of natural oils and a protective coating for water resistance. You can use the hard wax indoors and outdoors. It creates the barrier you want between the wood and the saltwater.
Tung Oil Preservative
Tung oil is another preservative that you can use on any furniture or wooden items that will be exposed to saltwater. The oil needs to be applied to a clean surface that is porous enough to absorb the oil when you apply it. You need to apply a thin coat of the tung oil, then wait at least 40 minutes.
After 40 minutes, apply another coat. Repeat the application method and wait 40 minutes until the wood doesn’t absorb the oil anymore. Then wipe the wood surface clean with a dry cloth.
Keep in mind that tung oil takes up to 30 days to properly cure, and you shouldn’t walk or use items you oiled for at least 7-10 days. Repeat these steps at least twice a year.
Natural Wood Preservatives
Many people would rather have purely natural options for protecting the wood. Here are some natural alternatives for protecting wood from saltwater.
Using Coconut Oil As A Wood Preservative
Many people use coconut oil as a barrier between wood and saltwater. Coconut oil has been used in cooking and other wellness products for centuries. Still, recently some conservationists and green living enthusiasts have started using it to preserve wood from saltwater damage.
You apply a thin layer of coconut oil to the wood and wait until it has seeped into the wood completely, repeat the process until the wood is saturated enough and no longer absorbs the oil. Then wipe with a clean cloth.
There is, however, a downside to using coconut oil as a wood preservative; it has to be regularly reapplied. The finish won’t last long, so you need to reapply the coconut oil at least once every 3 months to ensure the wood stays protected.
Using Olive Oil As A Preservative
You can also use a mixture of olive oil and lemon juice to preserve wood from water. The long-term effectiveness of this method has not been tested, but it is safe for those who have respiratory issues. Here is how you do it:
You mix two parts lemon juice with three parts olive oil. You can put this in a spray bottle and spray the wood with it, letting it dry completely between applications, or you can use a clean cloth dipped into the mixture, rub it into the wood, and let it dry before adding another coat.
Experts have suggested that you follow this pattern until the wood is saturated enough and no longer absorbs the oil. Repeat this process at least once every three months.
Using Linseed Oil As A Preservative
Linseed oil has been used in the US for 300 years to preserve wood. It is a tried and tested wood preserver even though it takes a long time to dry out properly. However, it protects the wood against a myriad of things, including saltwater, insect infestation, and wood rot.
Apply the first coat with a cloth, roller, or brush, wiping down the excess after 15 minutes. Wait for 24-hours before applying another coat of linseed oil, wiping down the excess oil (don’t forget this part, or you will have a sticky residue left on the wood).
Leave it for another 24-hours and repeat these steps until 4 coats have been completed. Now you need to let it dry.
Linseed takes 2-10 weeks to fully dry when applied to wood. It is worth the wait to use linseed oil as it gives a beautiful natural finish. The best way to ensure you get pure linseed oil is to buy some and boil it yourself. That way, you can be sure there are no petroleum additives added to the linseed oil you use.
Using Vinyl Sidings And End Caps To Protect Wood
One of the newest ways you can protect your wooden structures from saltwater damage is to use plastic vinyl sidings or caps to protect the wood exposed to saltwater. You can buy these sidings at hardware stores or have a contractor install them over the wood you are trying to protect.
Most of these sidings have UV inhibitors that protect against water damage and the sun’s hot rays. These vinyl sidings come in various shapes and colors, and you can choose the ones that resemble the wood the closets for a seamless finish.
Conclusion
Wood is one of the most beautiful materials to work with, and we want to make it last as long as possible. When faced with moist salty conditions, wood will get damaged after a few years. The best ways to preserve wood include buying the best quality wood like teak and ipe wood. Both are wonderful to use on outdoor projects and require minimal maintenance.
However, there are alternatives to using expensive wood, like buying wood treated with creosote or an oil-based preservative. It works best if you buy wood treated by professionals and can last up to 40 years in salty water conditions.
Resources
- https://www.reef2reef.com/threads/best-way-to-seal-wood-against-saltwater.603334/
- https://www.thuenen.de/en/hf/projects/protection-of-wood-in-contact-with-sea-water/
- https://www.fpl.fs.fed.us/documnts/techline/Techline_06-2011-001.pdf
- https://www.researchgate.net/figure/Characteristic-damage-to-treated-wood-caused-by-salt-a-Treated-deck-boards-exposed-to_fig1_316317038
