When it comes to building decks, fences, and outdoor structures, choosing the right lumber can make all the difference between a project that lasts and one that warps, twists, and requires constant callbacks. That’s where KDAT (Kiln Dried After Treatment) lumber comes in—a game-changing innovation in treated wood that’s revolutionizing the construction industry.
What is KDAT Lumber?
KDAT stands for Kiln Dried After Treatment, and it represents a crucial additional step in the pressure-treating process. Here’s how it works: lumber is first pressure treated with preservative chemicals, just like traditional treated wood. But then, instead of being sold while still saturated with moisture, the wood undergoes an industrial kiln-drying process that removes up to 80% of the excess moisture and chemicals.
This seemingly simple extra step addresses one of the biggest headaches in construction: wood movement. Traditional “wet” or “green” pressure-treated lumber contains significant moisture from the treatment process, and as this moisture evaporates over time (typically 8 months to a year), the wood naturally warps, cups, twists, checks, and shrinks.
Northern Crossarm Company has perfected this process since 1922, combining nearly a century of expertise with state-of-the-art kiln technology. Using controlled temperatures and carefully stacked lumber to ensure even airflow between each board, they achieve uniform drying that produces consistently superior results.
The KDAT Advantage: Six Key Benefits
1. Paint and Stain Ready
Unlike traditional pressure-treated lumber that requires 8-12 months of drying time before finishing, KDAT can be painted, stained, or sealed immediately after installation. Northern Crossarm takes this a step further with their KDAT Brown product line—pre-finished with a rich brown coating that eliminates the need for staining for up to four years. This means your deck looks beautiful from day one, with no waiting period whatsoever.
2. Minimized Warping and Cupping
Even drying in controlled kiln conditions minimizes the natural tendencies of wood to warp, cup, check, and shrink. Northern Crossarm’s rigorous quality control ensures that only the straightest, highest-quality boards make it to market. As one lumber yard manager noted after touring their facility: “If a board even looked questionable, it does not make the cut.”
3. Lighter Weight
KDAT lumber is noticeably lighter than wet treated wood, making it easier to handle, transport, and work with on the job site. Your crew will thank you—and they’ll work more efficiently with less fatigue.
4. Easier to Work With
Drier wood is easier to cut, saw, and plane. It produces less mess, causes less tool wear, and generally makes the construction process smoother. Northern Crossarm’s KDAT lumber cuts cleanly and holds its shape, reducing jobsite frustration.
5. Better Fastener Performance
KDAT provides superior nail and screw-holding power compared to wet lumber. The reduced moisture content means fasteners grip more securely and are less likely to work loose as the wood dries—crucial for long-term structural integrity.
6. Added Stability
For deck surfaces especially, KDAT substructure provides enhanced stability. When joists remain dimensionally stable, the decking above stays flat and true. This is why Northern Crossarm has become Wisconsin’s #1 treater, trusted by professional deck builders throughout the Great Lakes region.
The Composite Deck Problem—Solved
One of the most compelling reasons contractors are switching to KDAT involves composite decking. As Bob Heidenreich from The Deck & Door Store explains:
“If you take an ordinary piece of lumber that’s been treated, it will still be wet when you use it because chemicals and water have been pressure-treated into it. Over time, that board will naturally shrink, which can be a big problem when you’re using them to create a deck frame. As the framing shrinks, it can warp and distort the composite or wood decking resting on it, which can lead to deck failure.”
This is exactly why many professional deck builders have made Northern Crossarm’s KDAT their standard for all substructure work. By using joists that have already gone through their drying cycle in Northern Crossarm’s industrial kilns, they avoid the warping and movement that causes composite deck boards to buckle, gap, or develop that telltale “wave” appearance.
The result? Stable decks. Happy customers. Fewer callbacks.
Real-World Performance: What the Pros Say
The feedback from lumber yards and contractors who’ve adopted Northern Crossarm’s KDAT has been overwhelmingly positive:
Bob Heidenreich (The Deck & Door Store, Apple Valley, MN):
“As someone who’s been involved with deck building for 30 years, I’m definitely a fan of Northern Crossarm’s KDAT lumber. By using KDAT lumber for our deck frames, we receive fewer callbacks, and that’s good for business.”
Bryan Bolz (ABC Supply Co., Jackson, WI):
“We could not be more excited… customers love the quality of the KDAT material. When I toured the Northern Crossarm plant, I was absolutely blown away by the quality control. The sales staff is courteous and incredibly knowledgeable about their products. They are an absolute pleasure to do business with.”
David Albers (Lampert Lumber, Faribault, MN):
“Lamperts of Faribault is now in its fourth year of stocking Northern Crossarm’s KDAT Brown product line. Our builders had no problem with the extra costs when they saw the benefits—less weight and much less checking and cupping. The appearance of the brown stain is more appealing than the green when composite decking is going over joists.”
Kevin Anderson (Lyman Lumber, Eau Claire, WI):
“We tested the waters with Brown KDAT treated wood a few years back, and we quickly learned that customers LOVED the benefits of purchasing a finished, brown-coated KDAT product. The perceived value of a finished deck is much higher than the actual cost, meaning additional margin opportunity.”
Jere W. Haas (Haas Builders Supply, Inc.):
“During the first 6 months of carrying KDAT Brown treated lumber, my treated wood sales have tripled from previous year’s levels. This alone has been received with an overwhelmingly positive response from our customers.”
A Family Legacy of Quality Since 1922
When Joseph Bischel founded Northern Crossarm Company in 1922, he built the business on principles of honest work, integrity, and willingness to serve. Today, as a third-generation family-owned company operated by Pat Bischel, those same values remain the cornerstone of everything they do.
With 40 employees supporting the local Chippewa Falls, Wisconsin community and approximately 15 million board feet of inventory on the ground, Northern Crossarm has grown from a one-man manufacturing firm into one of the leading wood treating companies in the Great Lakes States area—without ever compromising on quality.
Cost Considerations: Is KDAT Worth It?
Northern Crossarm’s KDAT typically costs 15-25% more than traditional wet pressure-treated lumber—a reasonable premium considering the extra processing step and rigorous quality control involved. However, it’s still substantially less expensive (50%+ cheaper) than composite decking materials.
When you factor in:
- Reduced callbacks and warranty issues
- Elimination of the waiting period before staining (or no staining needed with KDAT Brown)
- Better job site efficiency due to lighter, easier-to-work material
- Improved customer satisfaction
- The reputation boost from delivering superior results
Most contractors find that Northern Crossarm’s KDAT more than pays for itself.
What to Expect (and Not to Expect)
While Northern Crossarm’s KDAT dramatically improves lumber performance, it’s important to have realistic expectations:
KDAT Will NOT Provide:
- Strict uniformity in dimensions (sawn lumber naturally varies; KDAT can only restore sizes close to their original dimensions)
- Exact moisture content (a target range of 12-19% is normal, with some variation expected)
- Complete elimination of natural wood characteristics (some checking, warping, and movement will still occur—it’s wood, after all)
What KDAT WILL Provide: Northern Crossarm’s commitment to quality means you get the straightest, most stable pressure-treated lumber available, with minimal defects and maximum performance.
Important Installation Note: Because wood absorbs moisture and swells when exposed to water, proper spacing remains crucial. When installing KDAT decking, maintain approximately 3/8″ gaps between boards to allow for expansion.
KDAT Applications: Versatility Meets Performance
Northern Crossarm’s KDAT lumber is extremely versatile, especially when stability matters most. It’s commonly used in:
- Deck boards and decking surfaces
- Deck rails and balusters
- Deck substructure (joists, beams, posts)
- Pergolas and arbors
- Fencing and privacy screens
- Bridges and boardwalks
- Marine construction
- Sound walls
- Flatbed trailers
- Storage sheds and backyard structures
From residential decks to municipal bridges, Northern Crossarm’s KDAT Brown product delivers consistent quality across all applications.
The KDAT Brown Difference
Northern Crossarm goes beyond standard KDAT with their signature KDAT Brown product—the highest quality KDAT lumber, coated in a rich, brown, pre-stained finish. This innovation offers several additional advantages:
- Immediate aesthetic appeal: No green-tinted wood showing through composite decking
- Extended maintenance-free period: Up to 4 years before restaining is needed
- Better color match: Blends beautifully with brown composite decking and natural wood tones
- Professional appearance from day one: Impress clients with finished-looking projects immediately
Species Spotlight: Southern Yellow Pine
Northern Crossarm’s KDAT is available in Southern Yellow Pine (SYP)—the most common deck framing material in the eastern United States. SYP offers several advantages:
- Strong and stiff structural properties
- High proportion of sapwood, which is ideal for absorbing preservative
- Excellent fastener-holding capability
- Wide availability in dimensional stock sizes
Common sizes include:
- Rail components: 2x4s, 2x6s, 4x4s, 6x6s, 2x2s
- Decking: 5/4x6s, 2x6s
- Joists, stringers, and beams: 2x8s, 2x10s, 2x12s
Why Contractors Choose Northern Crossarm
Ron & Greg Porasik (Screwheads Decking, Racine, WI):
“We use and supply Northern Crossarm’s KDAT lumber as it separates our company from the rest of the deck building supply pack. Northern Crossarm has been nothing but good to us and for us. Because of their sales staff and the hard-working people that make Northern Crossarm a great company, we look forward to many more years of doing business with them.”
This sentiment is echoed across the industry. Northern Crossarm isn’t just selling lumber—they’re building relationships with contractors, lumber yards, and DIY customers who demand quality and reliability.
The Bottom Line
After nearly a century of pressure-treating lumber, Northern Crossarm has elevated the process with KDAT—a genuine innovation that addresses real-world problems contractors face every day. While it costs a bit more upfront, the reduction in callbacks, improved workability, enhanced customer satisfaction, and the backing of a trusted, family-owned company make it a smart investment for professional builders and serious DIYers alike.
With 98 years of innovation, rigorous quality control, and a commitment to customer service that spans three generations, Northern Crossarm Company stands behind every board they produce. When you choose their KDAT lumber, you’re not just buying treated wood—you’re investing in a legacy of quality that started in 1922 and continues stronger than ever today.
Ready to experience the KDAT difference?
Rick Wedding
Rick Wedding is the founder of Building Supply Guy and has been in the building materials industry since 1987. His mission is to make selecting products and services for your home less complicated.
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