What Happens to Timber Over Centuries That Makes Old Buildings So Structurally Sound

The timber of old buildings can often remain strong for many centuries. The strength of this timber is often comparable to that of timber used in modern building construction.

Step into a medieval barn, a Tudor farmhouse, or a seventeenth-century church. Look at the roof structure. The timbers that support the structure have been performing their function for three, four, or five hundred years. The timbers are dark and dense, and have developed a patina that cannot be replicated by any finish available today.

These old-growth forests have lasted well into the 21st century for a reason that changes the way people think about the properties of timber.  Also, these forests are often the target of attempts to replace them with modern timber.

The trees that provided timber for historic buildings were old. Old in the sense that they were ancient. These trees took at least a century to grow to the point of felling for the construction of historic buildings. Due to the slower growth rate of these trees compared to those that grow in plantation conditions, the wood of these ancient trees has a very different structure from that of wood from plantation trees. The growth rings of these ancient trees are so close together that a magnifying glass is required to count them. The density of these ancient trees is what gives their wood its value.

Dense, slow-grown timber is harder, more stable, and more resistant to decay than fast-grown timber from the same species. It contains a higher amount of resin in its wood, which provides it with natural resistance to fungal and insect attack. Its cellular structure is more uniform than that of fast-grown timber, meaning that it is less prone to seasonal swelling and shrinking.

The older wood is harder and more stable over time. For Timber Merchants Winchester, visit https://www.timbco.co.uk/

This is the reason why restorers of historic buildings treat the original timbers as irreplaceable, even if they are superficially damaged. The properties that allow these timbers to remain structurally sound relate to both the species of the timber and the age of the tree from which it was cut. Both of these factors are factors that cannot be reproduced with new timbers.

The forests from which the medieval builders received their structural timbers do not exist in their former form. These old buildings stand because they are irreplaceable.