What to Look for When Buying Timber Slabs in New Zealand
Drying, Moisture Content, Checking & Sourcing Explained
Why Buying the Wrong Timber Slab Can Cost You Thousands
A timber slab can look perfect on the day you buy it — rich grain, beautiful live edges, solid weight. But months later, it may twist, split, cup or shrink. Suddenly, your dream table no longer sits flat, or your bench has deep cracks running through it.
In New Zealand’s changing climate, choosing the right timber slab is not about looks alone. It’s about how that slab was dried, where it came from, how stable it is, and whether it’s fit for its final use.
This guide is written for people early in the buying journey — homeowners, furniture makers, designers and builders who want to get it right the first time. You’ll learn what really matters when buying timber slabs in NZ, and how trusted suppliers like Plankville help remove the guesswork.
Key Takeaways
Timber slab quality depends more on drying and moisture than appearance
Moisture content must match the slab’s final environment
Some checking is normal, but poor drying causes serious cracks
Locally sourced NZ timber is more predictable and sustainable
Experienced suppliers help match slabs to real-world use
What Makes Timber Slabs Different from Regular Timber?
Unlike processed boards, timber slabs are cut closer to the tree’s natural form. They retain more character — live edges, grain movement, knots and growth rings. This is what makes them special.
But it also makes them more sensitive to moisture and movement.
A slab that is not dried or stored correctly will continue to change shape long after it’s installed. That’s why understanding drying, moisture content and checking is essential before handing over your money.
Plankville works with slabs, flitches and custom timber every day, supplying materials for furniture, outdoor structures, garden beds and sheds across New Zealand.
Drying – The Foundation of a Stable Timber Slab
Air Dried vs Kiln Dried Timber Slabs
Drying is the most important factor affecting slab quality.
Air drying is slow and natural. Slabs are stacked with airflow for months or years. This reduces internal stress and preserves colour, but it takes patience.
Kiln drying uses controlled heat to remove moisture faster. It is ideal for slabs intended for indoor use, where moisture levels must be consistent and low.
In New Zealand, many high-quality slabs are air dried first, then kiln finished, balancing stability with character. Plankville carefully manages this process depending on the slab’s end use.
👉Learn more about how slabs behave compared to milled timber.
Moisture Content: The Number That Decides Success or Failure
What Is Moisture Content?
Moisture content (MC) is the percentage of water still inside the timber. Trees are naturally wet. If slabs are used too early, they will continue to dry — and move.
As a simple guide in NZ:
Indoor furniture should be around 8–12% MC
Covered outdoor use suits 12–16% MC
Fully outdoor projects can tolerate higher levels, depending on species
A trustworthy supplier will measure and disclose moisture content, not guess it.
👉 Plankville selects and prepares slabs based on where and how they’ll be used — whether that’s a dining table, bench seat, planter box or shed structure.
Checking and Cracks: What’s Normal and What’s a Red Flag?
Understanding Timber Checking
Checking refers to natural cracks that appear as timber dries. Some checking is expected, especially near slab ends. Not all cracks are bad.
What matters is:
Depth and direction of cracks
Whether they continue to grow
Whether they affect structural integrity
Well-prepared slabs often have ends sealed early to slow moisture loss and reduce severe checking. Experienced suppliers also advise how cracks can be stabilised using joins, butterflies or resin — rather than hiding them.
👉 Seeing slabs in real projects helps buyers understand what’s acceptable and what’s not.
Where Your Timber Comes From Matters
Locally Sourced NZ Timber vs Imported Slabs
New Zealand-grown timber, such as macrocarpa, is well suited to our climate. It’s more predictable, easier to work with, and often more sustainable than imported slabs.
Ethical sourcing also matters. Responsible suppliers work with:
Salvaged trees
Managed forests
Minimal waste milling
👉 Plankville focuses on locally sourced timber wherever possible, supporting regional supply chains and ensuring traceability.
For buyers comparing macrocarpa slabs, independent guides like Hansen Timber and Cutek reinforce the importance of drying and treatment for long-term performance.
Matching the Slab to Its Purpose
A slab for a dining table is not the same as one for a garden bed or shed beam.
For example:
Furniture slabs need tighter moisture control and flatter profiles
Outdoor slabs prioritise durability and correct treatment
Structural slabs require careful assessment of grain and load
Plankville supplies timber for a wide range of uses, including:
This experience helps buyers avoid choosing timber that looks right but performs poorly.
Why Experience Matters When Buying Timber Slabs
Anyone can sell timber. Not everyone understands how it will behave six months from now.
Plankville’s hands-on experience with milling, drying, storage and real-world projects means buyers get practical advice, not sales talk. Slabs are assessed honestly, and customers are guided toward the right choice for their needs.
👉 If you’re unsure, starting a conversation early can save time, money and frustration.
Buy with Confidence, Not Guesswork
Buying timber slabs should feel exciting, not risky. When you understand drying, moisture content, checking and sourcing, you’re no longer guessing — you’re choosing with confidence.
Whether you’re planning a statement table, a custom bench, or an outdoor project, Plankville can help you select slabs that last.
👉 Explore available slabs or talk to the Plankville team today.
FREQUENTLY ASKED QUESTIONS
-
Check moisture content, drying method, cracks, and where the timber was sourced. Always match the slab to its intended use.
-
Indoor slabs should be around 8–12%, while outdoor slabs can be higher depending on exposure and timber species.
-
Yes, small cracks are natural. Large or growing cracks may indicate poor drying or internal stress.
-
Neither is always better. Many quality slabs are air dried first, then kiln finished for stability.
-
Yes. Macrocarpa is popular in NZ for its durability, workability and suitability for both indoor and outdoor projects.
