A Guide to Wood Checking and Splitting (2024)

FAQs

Is it better to split firewood green or dry? ›

The bottom line is that you can split both wet and dry wood. The latter is usually easier to split, though many people prefer to split the former so that it dries out more quickly. But if you use a log splitter, you shouldn't have trouble splitting either wet or dry wood.

Wood checking and splitting, a natural phenomenon in timber, occurs as the wood dries and loses moisture. This process leads to splits and cracks, known as “checks.” While they do alter the appearance of the timber, checks also add unique character without affecting the wood's structural integrity.

To many people, a check may look like a split. However, splits extend through the timber from one face to either the opposite or an adjacent face and are typically the result of rapid drying at the ends of the piece or excessive structural loads.

Look down the exterior of the round to avoid splitting any obvious obstructions such as large knots or twisted grain. The most effective blow is delivered near the edge of the round, NOT the center. By hitting near the edge (bark), the maul strikes at 90 degrees to the growth rings where they are wide and vulnerable.

Drying your wood

If you split your own wood, you also need to dry it. Fresh wood contains 80% moisture and needs to dry first. Wet wood won't burn easily and also produces a lot of smoke. Also make sure your blocks are not too big, because thick blocks take longer to dry.

Cracking (also referred to as checking) in lumber is somewhat inevitable. Over time, you'll likely begin to notice these cracks in the lumber that makes up your deck's framing.

To prevent wood from splitting as it dries, seal the ends with a suitable sealer or wax to slow down moisture loss. Additionally, stack and sticker the wood properly to allow for even drying and minimize stress.

Always Seal Cut Ends of Hardwoods

This helps minimize end checking from the most vulnerable area on a piece of wood – the end grains. Water moves quickly along the grains of wood. Slowing down the escape of water from the cut ends is crucial to proper installation techniques and affects the performance of the wood.

Shakes are natural occurring defects in standing trees caused by a lengthwise separation of latewood fibers. Shakes were once thought to be caused by external stress factors such as wind and temperature extremes (often called wind shakes); however, research has found that a bacterium is the true cause of shake.

Wood splitting (riving, cleaving) is an ancient technique used in carpentry to make lumber for making wooden objects, some basket weaving, and to make firewood. Unlike wood sawing, the wood is split along the grain using tools such as a hammer and wedges, splitting maul, cleaving axe, side knife, or froe.

What is the difference between checking and cracking? ›

Checks are small and do not present a structural problem in the home. A crack, also often called a split, is larger and more severe, often passing through the diameter of the log. These cracks are often due to damage to the log itself, improper drying techniques, or structural loading.

Tight-grained hardwoods that are seasoned or kiln-dried are less likely to split than green woods or softwoods.

You can split logs just by setting them upright on the ground (especially with a longer-handled tool), but placing them on some sort of chopping block, like an old stump end, is more stable, and will keep you from driving the blade into the ground.

If you are splitting green wood by hand, the general consensus is that wood is easier to split when it is green. Live wood contains a lot of moisture, so it is softer and more yielding to your maul. This is especially true of deciduous trees, such as oak and maple.

Turn the wood green then dry it. One rule for air Drying wood is about a year per inch. If you turn a 6” deep bowl from green wood with a 1” wall thickness you can dry it in less than a year and return it. I started a thread on working with greenwood in the tips and techniques.

Firewood needs to be dried from its freshly cut moisture level to below 20%, preferably to 15%. Softwood that is split and stacked in a dry place takes 4-6 summer months to dry to an acceptable moisture level. Hardwoods take at least 12 months to dry after being split and stacked.

Not only does green wood not burn as hot making it harder to heat your home, but it also causes excessive amounts of creosote to build up in your chimney at a dramatically faster rate. Creosote buildup is the leading cause of chimney fires which are extremely dangerous and burn down thousands of homes every year.