What to do about cracks in solid wood furniture

There is an old saying in the trade: if it never splits or cracks, it is not real solid wood. As living standards have risen, solid wood has become the first choice for many people buying furniture. In real life, though, almost every solid wood piece will show some cracking or movement at some point, and many owners assume the piece is faulty. In fact, solid wood is a bit like us: it reacts to sudden changes in the weather, especially at the turn of the seasons. Wood shrinks as it dries and swells as it takes on moisture. So why does solid wood furniture crack, and what causes it? Here is an explanation that we hope helps you deal with it.

Why solid wood furniture cracks

Climate. Furniture should be made with a moisture content one to two percentage points below the average moisture content of the air where it will live. Because climate differs from place to place, the right moisture content differs too.

How it is used. Poor use also leads to cracking and warping. Pieces placed right by a window, pieces that are regularly wiped with a wet towel, and pieces that get moved around a lot are all more likely to develop problems.

Moisture content. To give an example from China, the average moisture content of the air in Beijing is about 11.4 percent, so furniture for Beijing should be at roughly 9.4 to 10.4 percent. In the humid south of the country the average is around 15 percent, while in the north it is 12 to 13 percent. When furniture made in the south is shipped north, cracking can follow. The same thing happens in North America when a piece moves from a humid coastal city into a dry, centrally heated house. It also happens if the manufacturer did not dry the wood properly, or did not let it rest long enough after drying before building with it. Different parts of the piece then end up at different moisture levels, and when the environment changes, the stress left inside the wood makes it crack.

Transport. Knocks and bumps in transit are hard to avoid, and changes in weather along the way add to the strain. Solid wood is tougher and more durable than most other furniture materials, but it still needs proper care to avoid damage.

How to prevent cracking

Good routine care goes a long way toward preventing cracks. Four things to do:

1. Dust with a clean, soft cotton cloth, wrung out so it is only slightly damp.
2. Clean with a dedicated furniture cleaner to remove grease and stains.
3. Wax regularly, ideally once a season. Clean the piece with mild soapy water first and let it dry before waxing.
4. Add humidity. Indoor air gets very dry in northern climates during the heating season. A humidifier keeps the room at a comfortable level for both you and the furniture and does a lot to prevent cracking.

A few more habits help. Handle the piece gently when buying and moving it, keep it level and steady, and avoid rough treatment day to day. Wax and polish on a schedule. When something spills, wipe it with a soft cloth along the grain rather than reaching for chemical cleaners, which can crack the finish. Keep the furniture away from heat sources and out of direct sunlight, which fade the finish and shorten its life.