Carbon Sequestration and Salvaged Urban Lumber

We often hear that trees "clean the air" or "capture carbon," but what does that really mean—and what happens to that carbon when a tree comes down?

At Urban Lumber Los Angeles, our work exists at the intersection of environmental stewardship and craftsmanship. We’re committed to not just salvaging wood, but also helping our community understand why that matters—especially when it comes to climate impact.

🌳 How Trees Sequester Carbon

Trees pull carbon dioxide (CO₂) out of the atmosphere through photosynthesis. They use the carbon to build sugars, which in turn become the cellulose, lignin, and other structures that make up their trunks, limbs, and roots. This process removes carbon from the atmosphere and stores it in solid form within the tree.

Roughly 50% of a tree’s dry mass is carbon.

As long as the tree is standing—or the wood is preserved—that carbon stays out of the atmosphere.

🪓 What Happens When a Tree Is Cut Down?

When a tree is cut down and left to decompose, most of that stored carbon is released back into the atmosphere as CO₂ (and some as methane in anaerobic conditions). The same happens when trees are chipped for mulch, burned, or sent to landfill.

That’s why urban wood salvage is so important: it preserves the carbon by turning the trunk into long-lasting products like furniture, flooring, or architectural elements.

If you use salvaged lumber to build a dining table, that carbon stays locked away for decades, even generations.

🧮 How Much Carbon Is Stored in Salvaged Wood?

Here’s a simplified way to estimate the carbon sequestered in milled wood:

🔸 Step 1: Estimate the dry weight of the wood

Use a wood density chart (e.g. 35 lbs/ft³ for oak, 28 lbs/ft³ for sycamore) to calculate the dry weight of the lumber you’ve milled.

Dry Weight (lbs) = Volume (ft³) × Species Density (lbs/ft³)

🔸 Step 2: Estimate the carbon content

About 50% of the dry wood weight is carbon.

Carbon (lbs) = Dry Weight × 0.5

🔸 Step 3: Convert pounds of carbon to CO₂ equivalent

Each pound of carbon equals about 3.67 lbs of CO₂ equivalent, because of how carbon bonds with oxygen in the atmosphere.

CO₂ Equivalent (lbs) = Carbon (lbs) × 3.67
Or in metric: CO₂ Equivalent (metric tons) = Carbon (kg) × 3.67 ÷ 1,000

🔍 Example:

Let’s say a salvaged tree yields 250 board feet of dried hardwood (about 20.8 cubic feet of solid wood). For oak at 35 lbs/ft³:

• Dry Weight = 20.8 ft³ × 35 = 728 lbs

• Carbon Stored = 728 × 0.5 = 364 lbs

• CO₂ Equivalent = 364 × 3.67 = 1,336 lbs of CO₂ (about 0.61 metric tons)

That’s more than half a ton of carbon emissions prevented just by milling and preserving one tree’s trunk.

🌍 Why It Matters

When we help a homeowner salvage a tree and turn it into usable wood, we’re doing more than creating a beautiful piece of material—we’re keeping carbon out of the atmosphere.

It’s a small action in the big fight against climate change, but it adds up.

Preserving urban wood helps reduce emissions, conserve resources, and strengthen local supply chains. It's also a powerful reminder: we can honor the life of a tree long after it's fallen.

If you have a tree on your property and you're wondering whether any part of it can be saved, reach out. We’re happy to help you assess it and, if possible, preserve both its memory and its carbon.

Our Beloved Altadena

Altadena is more than where we live—it’s our home. Tucked into the foothills of the San Gabriel Mountains, it's a peaceful, wooded community that draws people who value nature, quiet, and connection. For those of us lucky enough to call this place home, the towering oaks, winding streets, and deep sense of neighborliness are part of who we are.

The fires that swept through Altadena on January 7th and 8th changed everything.

While we were fortunate—our home was spared—many of our neighbors lost everything. In the days and weeks that followed, we did what many others did: we showed up. Not because we were heroes, but because we were here. Because being present, helping where we could, and doing the quiet, necessary work was our way of coping with the chaos around us.

And when the smoke cleared—literally and figuratively—it became clear that we had another way to serve: through our work.

At Urban Lumber Los Angeles, we’re committed to offering pro bono consulting and significantly discounted drying services to our fellow Altadenans. If you have a tree on your property and don’t know what to do, we can help. In many cases, we can connect you with qualified professionals to assess the tree's health—sometimes, it can be saved. But if it can't, we’ll work with you to see if part of it can be salvaged and used in your future rebuild, or donated to Angel City Lumber’s Altadena Tree Bank.

The Tree Bank is a simple but powerful idea: trees that must come down are milled, dried, and made available back to the Altadena community at far below market cost. It's a way to preserve the character of our neighborhood, keep local material local, and help rebuild with meaning and intention.

We grieve with our friends, family, and neighbors. But we also believe in what's ahead.

Whether tree-related or not—if there’s a way we can help, we will. Our prayers are with everyone affected. Our hope, and our confidence, is in a future where Altadena comes back stronger, more united, and more resilient than ever.

What’s a Vacuum Kiln?

If you’ve ever worked with freshly milled lumber, you know it’s not immediately ready for fine woodworking. Properly drying wood is essential—too wet, and it warps or cracks; too dry, and it can become brittle or unusable. But how that drying happens matters just as much as that it happens.

At Urban Lumber Los Angeles, we specialize in vacuum kiln drying, but it’s helpful to understand the different types of wood drying methods—and why we’ve chosen to invest so deeply in this technology.

The Four Main Methods of Drying Wood

1. Air Drying

This is the oldest and simplest method. Cut lumber is stacked in a covered, well-ventilated area—usually outside—and left to dry naturally over time.

• Drying time: Several months to over a year, depending on thickness, species, and climate.

• Cost: Low, minimal energy or equipment needed.

• Common uses: Hobbyist woodworkers, farms, or remote locations without power access.

2. Solar Kiln Drying

Solar kilns are an upgraded version of air drying. Wood is stacked inside a small structure that uses the sun’s heat, paired with passive airflow and vents, to accelerate the drying process.

• Drying time: Typically 2-4 months, faster than air drying but still dependent on sunlight and weather.

• Cost: Low to moderate, depending on design.

• Common uses: Small-scale or eco-conscious drying operations.

3. Dehumidification Kiln Drying

This method uses a sealed chamber with a heat source and a dehumidifier to remove moisture from the air. It’s one of the most common methods in commercial lumber operations.

• Drying time: Several weeks to 2-3 months, depending on species and thickness.

• Cost: Moderate to high energy use, but fairly automated.

• Common uses: Cabinet shops, hardwood suppliers, production-scale drying.

4. Vacuum Kiln Drying

Vacuum kilns are the most advanced of the four. By lowering the atmospheric pressure inside the chamber, water in the wood can boil and evaporate at much lower temperatures. This allows for faster, more controlled drying with significantly less stress on the wood.

• Drying time: Typically 3 to 6 weeks, even for thick slabs.

• Cost: Higher upfront investment, lower energy per board foot.

• Common uses: High-end slab producers, custom woodworkers, urban lumber yards.

Pros and Cons of Each Method

Air Drying

Pros - Free, no electricity needed

Cons - Very slow; weather dependent; inconsistent results; risk of bugs and mold

Solar Kiln

Pros - Low operating cost, environmentally friendly

Cons - Still weather dependent; limited control; slower drying

Dehumidification Kiln

Pros - Reliable, consistent, widely used

Cons - Longer drying time; energy intensive; can overdry outer layers

Vacuum Kiln

Pros - Fast, efficient, minimal degrade or warping

Cons - Higher equipment cost; requires trained operator

Why We Chose the iDry Plus Vacuum Kiln

At Urban Lumber Los Angeles, we’re focused on preserving local trees and helping people give them a second life—so quality and efficiency matter. After researching every method available, we chose the iDry Plus Vacuum Kiln for several key reasons:

• Speed without sacrifice – We can reliably dry 3-5” thick hardwood slabs in a matter of weeks, with minimal checking, warping, or case hardening.

• Capacity and scalability – Each iDry Plus unit can handle over 3,000 board feet. With two units running in rotation, we now dry up to 7,000 board feet per month.

• Energy efficiency – Vacuum drying uses far less energy per board foot than conventional kilns.

• Consistency – Our results are repeatable and dependable, even for challenging species like coastal live oak and sycamore.

After a full year of running our first iDry Plus, we were so impressed with the performance, reliability, and finished quality of the wood that we purchased a second unit. It’s not just about speed—it’s about drying wood the right way, reducing waste, and honoring the material.

Conclusion

Vacuum kiln drying isn’t just a high-tech gimmick—it’s the future of sustainable, precision wood drying. Whether you’re salvaging a tree from your yard or preparing material for a large-scale millwork project, our vacuum kilns offer unmatched speed, control, and results.

Got questions about drying your own lumber? Reach out to us—we’d be happy to walk you through the process.