Janka Hardness

Floor Sanding Sydney

The great advantage of solid wooden floors is their durability. They resist wear and tear and will last for decades. And when they do show signs of superficial surface wear they can be re-sanded to make them look as good as new. It is not uncommon to have floors re-sanded after about 10 years of use.

Hardness of Floor Timber

The wood produced by different species of trees will vary in strength, hardness and appearance. These factors can also vary with processing and staining.

The hardness of wood is determined with the Janka test. This measures the pressure required to press a 0.444 inch steel ball half way into a wooden surface (a depth of 0.222 inches). The result gives the Janka number. In Australia the Janka number is given in kilo Newtons kN.

Timber suitable for flooring will require a Janka hardness of about 6kN or greater. Woods with Janka numbers of up to 12kN are not uncommon. A few timbers rate up to 16kN.

Past a certain point the Janka number is not really important. Most timbers sold for flooring are hardwoods of sufficient durability, and under normal conditions they will last for decades, with occasional surface re-sanding. 

Floor timber can be chosen mainly for colour, pattern and appearance rather than durability, because almost all timber flooring is sufficiently durable.

Floor Sanders Sydney

Talk to us if you have any questions about having your floors re-sanded, or for advice on re-staining or lime wash.

Environmental Wood

There have always been questions about how cutting down forests will affect the environment. Loss of trees and the expending of energy that produces carbon dioxide are legitimate concerns. But it is possible to use quality timber and still have minimal impact on the environment.

Hardwoods and Environment

Trees absorb carbon dioxide gas and produce oxygen. The absorption of carbon dioxide is good for the environment.

Growing trees absorb a significant amount of carbon dioxide. But once the tree is fully mature the amount of carbon dioxide absorbed is much lower. And once the tree dies and starts to decompose the carbon dioxide is re-released back into the atmosphere. A forest of trees, with growing and dying trees, will absorb and release about the same amount of carbon dioxide, making the total production basically zero.

The best way to use trees for reducing carbon dioxide in the atmosphere is to constantly grow new trees. These trees can then be cut down and used as building material. The new trees will absorb carbon dioxide as they grow, and most of this carbon dioxide will remain stored in the timber which is then used for building. The carbon dioxide is only re-released if the wood rots or is burnt.

Hardwood is natural, and the use of hardwood timber for building material is a fairly good option for the environmentally conscious. Timber from trees requires only a moderate amount of energy in order to become suitable building material. And the growing of more replacement trees is very beneficial for the environment.


Bamboo is a grass rather than a wood, but many bamboo products can be used as building materials that replace traditional timber. Bamboo flooring is one modern example. It is much faster growing that timber, taking about 7 years to mature instead of several decades, so new building material is reasonably quick to produce.

Bamboo building materials look to be quite beneficial for the environment.

 Floor Sanding Sydney

Good hardwood floors will last for decades, if not more than a century. This makes then a sound investment for any home. The timber is a renewable resource, and because the flooring lasts so long these is minimal impact on the environment.

Floor sanding can remove the top layer or wood from a timber floor, effectively making the floor as good as new. With regular wear it is not uncommon to re-sand floors ever 10 years. The restored floor can then be re-stained or redecorated to suit a new décor, or returned to its previous finish.

Floor Sanders Sydney

After Floor Sanding Sydney

If you have had your wooden floors re-sanded, or if you want your unfinished new floors to have a certain austere look, consider lime wash.

More than Floor Sanding Northern Beaches

Lime wash developed as a means of protecting wood, an inexpensive alternative to paint. But people liked the light colour of lime wash and the way it enhanced the grain. So lime wash became popular for some types of décor.

Lime wash is a mixture of calcium hydroxide and chalk. When applied to an open grain floor this given a smooth yet powdery appearance, rather like the chalk that is part of the wash. Lime washed floors can really brighten up the look of a room.

An unexpected benefit of lime wash is that it doesn’t show the dust. Floors will look pale and clean as long as they are free from footprints.

The look of lime wash and be combined with a protective polyurethane coating.

Floor Sanders Sydney

A floor cannot be lime washed if it still has a vanished or painted surface. If you want the look of lime wash than have the floors sanded first. And consider a protective coat with the Lime stain.