Why Are Hardwoods Not Commonly Used As Structural Wood

Structural hardwoods may be strength graded in accordance with bs 5756.

Why are hardwoods not commonly used as structural wood.

These classifications are not directly related to the shrinkage of green timber. It is not good for structural uses. These vessels differ in size shape and structure. Conversely proper hardwood is impervious to damage in this way.

The deeper the furrow the softer the wood. Hardwoods are generally far more resistant to decay than softwoods when used for exterior work. Hardwood trees take a long time to grow around 60 years sometimes up to 100. Interestingly commercial wood industry uses a similar method called the janka test to gauge the hardness rating of a species of wood.

According to madan mehta walter scarborough diane armpriest author of building construction the difference between hardwood and softwood is not only based on the density of the wood. Believe it or not there are literally hundreds of species of hardwoods. 1997 specification for visual strength grading of hardwood. Generally the distinction between these two types of woods is based on their botanical characteristics.

Slow growth unlike softwood hardwood forests take longer to replenish due to the tree s slower growth rate. The hardwoods preferred for structural use generally have greater natural durability than the commonly used softwoods. Hardwoods are generally used for more load bearing heavy structural duties such as walls floors and ceilings but due to their often appealing visual appearances are also often used for furniture veneers and cabinet making. This is because several hardwoods are lighter than softwoods.

Chipboard is commonly covered using a real wood veneer or. As the name suggests the tree is commonly harder than a softwood. The dominant feature which hardwoods have which separate the two prominently is the presence of vessels or pores. Hard to work with due to its density hardwood tends to be a lot harder to work with during construction.

Exotic temperate and tropic species to name but a few. They do not therefore normally require preservative treatment provided that the vulnerable sapwood is excluded. If it is a softwood your nail will create a scratch or furrow in the wood. Decorative flooring use a species with small movement.

For structural purposes movement is not usually significant but if you require stability in varying humidities e g. The cell structure being more complex make it harder to work with. Softwoods contain more glucomannans than hardwoods while hardwoods contain more xylans. However solid hardwood joinery is expensive compared to softwood and most hardwood doors for instance now consist of a thin veneer bonded to mdf a softwood product.