Firewood is one of those household items that can quietly add moisture to a house. Freshly cut or recently rained-on wood holds water, and as it dries it releases that water into the air around it. In a St. Louis home, that air often ends up in a basement, an attached garage, a mudroom, or a corner of a living room where the stack sits against a wall. This guide covers where to keep firewood, how to tell whether it is too wet, and what to check if you already keep a stack indoors.
Why Firewood Matters for Indoor Humidity
Wood is naturally hygroscopic, which means it absorbs moisture from the air and gives moisture back to the air as conditions change. A stack of logs in a closed room can raise local humidity over time, especially when the wood is still seasoning. The effect is most noticeable in spaces that already run damp, such as finished basements, lower levels after a wet spell, or rooms with little airflow.
Firewood can also bring other problems with it. Bark and wood can hold mold spores, and damp stacks often develop surface growth. Insects that live in wood, including some beetles and termites, may travel from a stack into structural wood if the pile sits directly against the house. A stack that stays wet for months can also stain flooring, carpet, and painted walls.
Store Wood Outside, Away From the Foundation
The safest default for most St. Louis homeowners is to keep the main woodpile outdoors on a rack or pallet, away from the house. Lifting the wood off the ground lets air move underneath it and keeps soil moisture from wicking into the bottom logs.
- Place the stack on a rack, pallet, or raised frame instead of directly on soil, gravel, or concrete.
- Keep the pile away from the foundation wall, basement window wells, and any spot where water collects after heavy rain.
- Cover the top of the stack with a tarp or roof panel, but leave the sides open so air can pass through.
- Choose a location with sun and breeze when possible, since that speeds drying.
- Stack the wood in rows with gaps between them rather than in a tight block against a fence or wall.
Bring in Only What You Need
Many homeowners move a large amount of firewood indoors all at once and leave it in a basket or corner for weeks. A better approach is to carry in a day's or a few days' supply at a time. This keeps the bulk of the wood outside where it can dry and reduces the chance that a damp load is sitting in your living space.
Before you bring wood inside, look at it. Wood that is spongy, dark at the ends, or has white, gray, or green fuzzy growth on the surface is not ready to store indoors. Set it outside to dry further, and do not burn wood that shows heavy growth or rot.
If You Already Keep a Stack Indoors
Some St. Louis homes keep a small stack in a basement, mudroom, or garage because it is convenient. If that is your setup, check the space in a few simple ways.
- Look at the wall and floor directly behind and under the stack. Dark staining, bubbling paint, soft drywall, or a musty smell in that spot are signs that moisture is building up.
- Move the stack for a day and inspect the area. Any fuzzy growth on the wall or flooring needs attention, and a large or spreading area is a job for a professional remediation company, not a weekend cleaning project.
- Place a hygrometer, a simple device that reads relative humidity, a short distance from the stack and compare it with a reading in another part of the room. A reading that stays high over several days, especially near the wood, tells you the stack is adding moisture to the air.
- Check the surface of the wood itself for growth before it comes indoors.
Testing the Wood Itself
A handheld moisture meter made for wood can show how dry a log is inside. Many people also use a simpler method: knock two pieces of seasoned wood together. Dry, well-seasoned wood tends to make a sharp, hollow sound, while wet wood sounds dull. Splitting a piece and checking the cut face also helps. Dry wood usually shows cracks radiating from the center and has a lighter, drier look, while wet wood looks darker and feels cool and damp.
Cleaning Up Without Making It Worse
If you find surface growth on firewood or on a nearby surface, dry the area first and remove loose debris. Wear a mask and gloves when brushing off growth, and avoid stirring dust into the air. Keep the room ventilated while you work. Do not seal wet wood or wrap it in plastic indoors, since that traps moisture against the wood and the surfaces beside it.
When to Get Help
Call a qualified contractor if the damp spot is large, keeps coming back after the wood is moved, or appears behind the wall or under flooring. Moisture that comes from the house itself, such as a leak or seepage through a foundation wall, will not be solved by moving firewood. Firewood storage is one small piece of keeping your St. Louis home comfortable, so treat it as part of a broader check of drainage, ventilation, and the rooms where moisture settles.