Can Pallet Wood Get Wet? What Every DIY‑er Needs to Know
*You’ve probably seen those weather‑worn pallets stacked by the side of a loading dock and thought, “That wood looks perfect for a coffee table, a garden bench, or even a rustic headboard.” Before you start sawing, sanding, and staining, there’s one crucial question you have to answer: Can pallet wood get wet, and if it does, what will happen?
In this post you’ll learn:
| Topic | Why It Matters to You |
|---|---|
| Types of pallet wood | Not every pallet is created equal; some are treated to resist moisture, others are not. |
| Moisture content & wood health | High moisture can warp, rot, or attract insects—issues that can ruin a project. |
| Finishing & sealing strategies | Proper finishes can turn a water‑prone board into a durable surface. |
| Safety & compliance | Some treatments are illegal for indoor use or may off‑gas harmful chemicals. |
| Practical tips for drying, storing, and maintaining | Simple habits that keep your reclaimed wood happy for years. |
By the end of this guide you’ll be able to decide whether a pallet you’ve rescued is suitable for indoor furniture, outdoor décor, or should be discarded altogether.
1. The Basics: Pallet Wood and Water
1.1 What is pallet wood made of?
Most pallets are built from softwoods (pine, spruce, fir) because they’re cheap and easy to nail. A smaller share are made from hardwoods (oak, maple, poplar) – often for higher‑value loads. The species matters because hardwoods are naturally denser and more resistant to moisture absorption than softwoods.
| Pallet Wood Type | Typical Species | Approx. Density (lb/ft³) | Natural Water Resistance |
|---|---|---|---|
| Softwood pallet | Pine, Spruce, Fir | 25‑35 | Low – swells quickly when wet |
| Hardwood pallet | Oak, Maple, Poplar | 38‑45 | Moderate – slower swelling |
| Treated pallet | Any (often pine) | Varies | Depends on treatment (see below) |
1.2 How does wood react to water?
Wood is a hygroscopic material – it absorbs and releases moisture from the surrounding air until it reaches equilibrium with the ambient relative humidity (RH). When the moisture content (MC) climbs above about 20 %, the cell walls begin to swell. If the MC climbs higher than 30 %, you’ll start to see:
- Warping (bow, cup, twist)
- Checking (surface cracks)
- Rot (fungal decay) if the wood stays wet for weeks
- Insect infestation – termites, carpenter ants love damp wood
These changes are usually permanent; once a board has warped, you can’t fully restore it to its original flatness. That’s why understanding how wet your pallet wood gets is the first step to a successful project.
2. How Can Pallet Wood Get Wet?
| Source of Moisture | Typical Scenario | Likelihood on a Pallet |
|---|---|---|
| Rain or snow | Outdoor storage, pallets left under a shed | Very high if pallets sit uncovered |
| Condensation | Pallets stored in a cold garage during winter | Moderate – especially if airflow is poor |
| Spills | Dropped paint, juice, or other liquids during handling | Low to moderate (depends on your workspace) |
| Ground contact | Pallets stacked directly on damp soil or concrete | High – capillary action draws moisture up |
| Treatment chemicals | Some pallets are “wet” with preservatives or fire retardants | Very high – chemicals are mixed with water or solvents |
If any of these scenarios apply to the pallets you’re considering, you must treat the wood accordingly before it becomes a permanent part of your project.
3. Pallet Treatments: What’s Inside the “Wet” Label?
You’ll often see a stamp on the side of a pallet that tells you how it was treated. The three most common codes in the United States are:
| Mark | Meaning | Water Resistance | Indoor Use? |
|---|---|---|---|
| HT | Heat‑treated (≥ 56 °C for 30 min) | Good – no water‑based chemicals | ✔️ Safe (but still check for paint) |
| MB | Methyl bromide fumigation (gas) | No effect on moisture | ✔️ Generally safe after airing out |
| KD | Kit (or D)rain (treated with chemicals such as chromated copper arsenate – CCA) | Poor – chemicals are water‑based and can leach | ❌ Not recommended for indoor projects; may be illegal in some states |
If your pallet is stamped KD, you should treat it as if it will stay wet – the chemicals can migrate when the wood absorbs water, potentially contaminating food surfaces or indoor air.
Bottom line: Only HT and MB pallets are candidates for interior furniture, and even then you should still sand and seal the wood.
4. Drying Out Wet Pallet Wood
4.1 Quick‑Dry vs. Slow‑Dry
- Quick‑dry (using a garage heater, dehumidifier, or fan) can get the MC down to 12‑15 % in a few days, but it also creates uneven drying, which may cause cracking.
- Slow‑dry (stacking in a shaded, well‑ventilated area for 2–4 weeks) yields a more uniform MC and less stress on the fibers.
Best practice: If you have time, combine both—air‑dry for a week, then finish with a low‑heat dehumidifier for the final push.
4.2 How to Test Moisture Content
A cheap pin‑type moisture meter (≈$20‑$30) will give you a quick reading. Insert the probes into the wood at three points (center, near the edge, and a corner) and average the results.
| Desired MC | Typical Use |
|---|---|
| 6‑8 % | Interior furniture (dry climate) |
| 10‑12 % | General indoor projects |
| 12‑15 % | Outdoor furniture (will be sealed) |
| >20 % | Not ready – must dry further |
If the reading is above 15 %, keep drying.
5. Finishing Pallet Wood to Resist Future Moisture
Even after you dry the wood, you still need a protective barrier. Here are three proven finish systems, each with pros and cons:
| Finish System | Application Steps | Water Resistance Rating* | Cost (per ft²) | Ideal For |
|---|---|---|---|---|
| Oil‑Based Polyurethane | 1️⃣ Sand → 2️⃣ Clean → 3️⃣ Apply 2‑3 coats (oil‑based) | ★★★★★ (excellent) | $0.40‑$0.60 | High‑traffic indoor tables |
| Exterior‑Grade Spar Varnish | 1️⃣ Sand → 2️⃣ Clean → 3️⃣ 2‑3 coats (spar) | ★★★★☆ (very good) | $0.30‑$0.50 | Outdoor benches, garden planters |
| Penetrating Oil (Tung or Linseed) + Wax | 1️⃣ Sand → 2️⃣ Apply oil (overnight) → 3️⃣ Buff with wax | ★★★☆☆ (moderate) | $0.20‑$0.35 | Rustic décor, low‑moisture areas |
*Rating based on ASTM D1654 water‑absorption tests (higher stars = less water uptake).
Tip: Always sand against the grain after each coat to keep the surface smooth and avoid raised fibers.
6. Storing Pallet Wood Safely
Even the best‑finished piece can become a soggy mess if you store it wrong. Follow these quick rules:
- Elevate – place wood on pallets or 2‑inch spacers to keep the bottom side off damp floors.
- Ventilate – keep a 2‑inch gap between boards for airflow; a simple wall‑mounted rack works wonders.
- Cover, but don’t seal – a breathable tarp (canvas) protects from rain while allowing moisture to escape.
- Rotate – move the oldest boards to the front of the stack every few weeks to ensure even drying.
7. Real‑World Scenarios: When Wet Pallet Wood Is Acceptable
| Scenario | How to Treat | Why It Works |
|---|---|---|
| Outdoor garden bench | Use exterior‑grade spar varnish, raise the bench on concrete footings, and apply a water‑repellent seal after each season | The finish blocks rain; the concrete footings prevent ground wicking |
| Indoor coffee table (low budget) | Sand, apply two coats of oil‑based polyurethane, and keep the table away from windows where condensation forms | Polyurethane creates a hard, impermeable surface suitable for dry indoor air |
| DIY pallet wall art (indoor, decorative only) | Clean, lightly sand, then use a matte acrylic sealer | The piece is primarily aesthetic; minimal moisture exposure is expected |
If you’re planning to use pallets for structural purposes—say, a load‑bearing deck or a roof—don’t rely on a simple seal. You’ll need engineered lumber or pressure‑treated wood that meets building‑code standards.
8. Frequently Asked Questions (FAQ)
Q1: Can I wash pallet wood with a pressure washer to remove dirt?
A: You can, but only if you plan to let the wood dry completely afterward (at least 48 hours in a low‑humidity environment). Pressure washing forces water deep into the fibers, raising the MC dramatically. If you do wash, follow up with a thorough air‑dry or dehumidifier session before sanding or finishing.
Q2: Does painting pallet wood protect it from water?
A: Paint creates a barrier, but most cheap interior paints are breathable and will not stop water vapor from reaching the wood. For outdoor exposure, use a exterior‑grade acrylic or oil‑based paint, and apply a clear topcoat for added protection.
Q3: My pallet has a “KD” stamp. Is there any safe way to use it indoors?
A: KD pallets are chemically treated with substances like CCA, which can leach when the wood gets wet. Even if you sand and seal, the chemicals may migrate over time. The safest route is to avoid indoor use; reserve them for outdoor, non‑food projects, or discard them.
Q4: How long does it take for a wet pallet board to dry naturally?
A: In a warm, dry garage (70 °F / 20 °C, 40 % RH) a 1‑inch thick softwood board can drop from 25 % MC to 12 % in 7‑10 days. Thicker boards or cooler, humid environments may require 3‑4 weeks.
Q5: Can I use a wood‑staining pen to touch up small water stains on pallet furniture?
A: Yes, but first sand the stained area lightly, then apply the stain and seal it with a compatible finish. If the water stain is deep, you may need to refinish the whole surface for a uniform look.
Q6: Is there a risk of mold growing on pallet wood that got wet?
A: Absolutely. If the wood remains above 20 % MC for longer than 48 hours in a warm environment (above 65 °F / 18 °C), mold spores can colonize. Always dry the wood thoroughly and consider adding a mold‑resistant additive to your finish if you expect high humidity.
9. Quick Checklist Before You Start Your Pallet Project
| ✅ | Action |
|---|---|
| 1 | Identify the treatment code (HT, MB, KD). Discard KD for indoor use. |
| 2 | Inspect for rot, cracks, or insect damage – any board with soft spots should be tossed. |
| 3 | Measure moisture content with a meter; aim for ≤12 % before sanding. |
| 4 | Dry the wood – air‑dry for 1‑2 weeks, then finish with a dehumidifier if needed. |
| 5 | Sand (80 → 120 → 220 grit) and clean with a vacuum or tack cloth. |
| 6 | Choose a finish based on indoor/outdoor use and desired look. |
| 7 | Apply finish in thin, even coats; sand lightly between coats. |
| 8 | Store finished pieces on a raised shelf, covered with a breathable tarp. |
| 9 | Enjoy your reclaimed‑pallet masterpiece, knowing it won’t turn into a soggy mess! |
10. Closing Thoughts
Yes, pallet wood can get wet, and when it does, the consequences range from harmless surface stains to serious structural failure. By checking the treatment stamp, measuring moisture, drying it properly, and applying a suitable seal, you can turn a weather‑worn pallet into a sturdy, beautiful piece of furniture that stands up to the elements—or to a coffee‑stained living‑room table.
Remember: the key isn’t to avoid water entirely, but to control how water interacts with the wood. With the right preparation, you’ll keep your reclaimed pallet projects looking great for years, while also honoring the spirit of sustainable, up‑cycled design.
Happy building!