What’s the difference between sapwood and heartwood?

If you follow our blog, you have probably seen us mention heartwood and sapwood fairly often. In the timber industry, these are two very common terms. But what do they mean? In case you are not sure, we have put together a quick guide explaining everything you need to know.

What is Sapwood?

When we talk about sapwood, we are talking about the timber on the outer part of the tree trunk. It is the wood directly under the bark. Sapwood is created by a very thin layer of cambium cells, and is responsible for transporting minerals and water throughout the tree, from the roots to the crown. If you are looking for sapwood, it is usually the lightest coloured wood in the tree.

What is Heartwood?

Moving towards the centre of the tree and past the sapwood, you will find heartwood. This makes up the inner part of the trunk. It is actually formed from old sapwood cells which have begun to solidify and thus support the tree as it grows upwards. The older a tree is, the larger the volume of heartwood it will have. 

Aside from the dead sapwood cells, heartwood also contains compounds that make it stronger, more durable and darker in colour.

Sapwood vs Heartwood

The easiest way to determine between heartwood and sapwood is by colour. Usually, the heartwood is a dark brown or red colour, whilst sapwood is white or a light yellow/gold. The lighter colour of sapwood is as a result of the higher moisture content.

However, it is important to note that this is not always the case and some hardwoods can be light in colour too, such as beech.

Heartwood is always more durable, denser and stronger as it contains very little moisture. Durability and resistance to rot is also higher, which is why it needs less maintenance when used for decking or cladding. Sapwood of any species is not durable for external use. Heartwood is usually preferred for timber construction projects. It is harder, will last longer and is better suited for a wide range of applications. However, because it is so hard, it can be more difficult to use.

Different Uses For Heartwood and Sapwood

Heartwood from durable timber species has many external uses, including decking and cladding, as well as interior uses such as flooring and furniture making. It is also used to build boats, piers and even musical instruments! Sapwood is more often used as wood to practice working with as it is cheap and readily available. It can also be used for small parts of a larger woodworking project.

Source Sustainable Heartwood From EcoChoice

If you are undertaking a timber construction project and are looking for sustainable heartwood, we can help. All our timber comes from independently certified, responsibly managed forests, helping you build with a good conscience, and securing the safety of the world’s forests for generations to come. Get in touch with us today to find out more.