Which timber – softwood or hardwood? What is Accoya?
Hardwood and softwood are historical terms and should be considered as general classifications.
Softwood is a term used to describe timber from coniferous or needle-leaved trees and hardwood from
deciduous and evergreen broad-leaved trees. The terminology, therefore, cannot be relied upon to
describe the durability of the timber and there are notable exceptions such as balsa wood which is one
of the lightest, least dense woods and is considered to be a hardwood. However, evergreens do tend to be
less dense than decidous trees and most hardwoods tend to be more dense and are, therefore, sturdier.
European oak, a hardwood, is one of the most durable timbers for exterior use. It can be treated with oil to preserve its blond appearance or can be left untreated and will gradually fade leaving it silver grey. Oak is one of the more expensive hardwoods and should not be painted. Utile and sapele are commonly used tropical hardwoods, suitable for exterior use and are cheaper than oak. These species can be painted or stained. Redwood is the preferred softwood choice for exterior joinery and this can be coated with preservative prior to a paint finish to prolong the life of your joinery. Accoya is the latest high technology in wood. The Accoya process takes sustainably-sourced, fast growing softwoods and treats these in a non toxic process that ‘enables nature’ to create a durable and stable product with good environmental credentials.
December 2007 - Building Regulations and FENSA