A new wood preservation method for me: pine tar

This is what it looked like right after I finished applying Thompson’s Timber Oil.

But so far, none of the options I’ve tried have lasted more than a year. After a year, the finish wears off and the boards begin to look incredibly dry, grayish and rough, and the color is faded and uneven.

Here’s a closer look at how bad the plaques start to look after just one year. The poles are PVC boards, so they just get dirty. After a good wash, they still look fantastic. But the cedar boards on the porch start to look horrible pretty quickly…

In preparation for priming and painting, I once again sanded my porch to prepare it for the new finish. So right now it looks very good again. All that old finish is gone, the gray is gone, the roughness is gone and the cedar boards look fresh and ready to be sealed. And although I wasn’t really excited about painting them, I thought it was my best option at the moment.

But as often happens, I received several comments on previous posts that made me question my decision to paint. I received comments like this…

“I would use an oil-based stain and a tung oil finish to preserve your beautiful cedar wood. This information is online: Preserving outdoor cedar with an oil-based stain and tung oil requires combining a penetrating UV color protection stain with tung oil to create a water-resistant seal. This two-step process penetrates deep into the grain of the wood to protect it from weather and decay without peeling.”

It sounds great, but I’ve already tried it. Cabot Australian Timber Oil is a combination of three oils, including tung oil, combined with dye. I was there, tried it and it lasted a year (if that) before it started looking horrible.

But then I also get comments like this…

“A word of caution: When we bought our house, the deck had just been painted. We’ve only been here a few years and it looks absolutely horrible. The paint is peeling everywhere. We’re not looking forward to the big job of scraping off all the paint so we can stain it instead.”

And of course, that’s always the problem with painting wood for exteriors. The painted finishes look great…until they don’t. Wood likes the breath. It is always expanding and contracting, and even more so when it is outside. When you paint wood with latex paint, you are basically coating the wood with plastic. It’s fine as long as the coating is in perfect condition. But the moment the finish fails at any point, even if it’s just a small crack, water will find its way there, soak into the wood, and then have no way to escape. So water gets trapped inside the wood under that layer of plastic coating, and that causes all kinds of problems like rotting wood and peeling paint.

But as I was reading and researching what the best option was, I came across something I had never heard of before called pine tar. Pine tar comes from the trunks of pine trees and is harvested by heating the wood by lighting a fire around it, which decreases the viscosity of the tar, allowing it to be harvested from the wood.

If you want to see the (small scale) process of harvesting pine tar, I came across this fascinating video of a man harvesting his own pine tar from which he made not only a sealant that can be used on wood, but also an ointment that can be used on the skin for cuts and scrapes.

Pine tar has been used for millennia for wood preservation, dating back to the Norse Iron Age when it was used to protect ships and boats. It has been used to protect wooden buildings such as the Urnes Stave Church, which is the oldest and most elaborately carved and decorated wooden church in Norway, built around 1130 AD

All that to say, if it worked for the Vikings, I think it will work for my porch.

Once pine tar is harvested from trees, it can be diluted (usually with purified crude linseed oil) and painted with a brush as if it were an oil-based stain. It penetrates deep into the wood and provides natural UV protection while sealing the wood and protecting it against insects, rot, water, etc.

The best thing about pine tar is that it is completely natural. It does not contain solvents or petrochemicals, making it completely environmentally friendly. And again, it has been used for millennia specifically because it is a natural and long-lasting method of wood preservation.

Pine tar is not as popular or well-known here in the US as it is in other parts of the world like Norway, but there are companies that sell pine tar in the US (or ship to the US). You don’t get a wide range of colors in pine tar like you do with standard stains found at local big box stores, but I found a beautiful dark brown that will work perfectly for my front porch and the steps of my workshop. It comes from a company called Earth + Flax. Pine tar comes in a container like this…

And the dark brown color looks like this…

So after spending about an hour yesterday reading about pine tar, watching the videos on the Earth + Flax Instagram page, and learning all about pine tar, I decided to give it a try. I’ll be the guinea pig for all of us and see how well this age-old method of climate preservation works for a central Texas cedar porch.