As many homeowners know, wood is a material that shrinks and swells based on the weather. When it’s hot and humid, it absorbs excess moisture from the air and expands, and when it’s cold and dry, it expels moisture and contracts. That’s why houses creak and groan from time to time. They’re not ghosts—just the natural properties of wood being affected by the weather.
Unfortunately, this also happens for all types of timber-based flooring, which needs to be taken into account by flooring installers to prevent the material from buckling, lifting, cracking, or becoming damaged in other ways. They avoid the issue by including an expansion allowance in the flooring, in the form of timber floor expansion joints.
But what are they, exactly? Let’s find out.
Note: at Brisbane’s Finest Floors, we only use cork expansion joints, which we sand and coat to blend in with the timber flooring. But this article is about all types of timber floor expansion joints.
A cork expansion joint. Image from Peak Oak
Timber floor expansion joints are a joint that allows for the expansion and contraction of wooden floorboards, to prevent them from becoming damaged. The joints are usually filled with a material that can handle expansion and contraction, such as cork, neoprene, urethane, or polysulfide, and either sanded down and coated or covered with a material such as aluminium or wooden skirting (depending on where they are placed).
The joints are usually between 5 to 8mm wide and are typically placed along the edges of the flooring. They can also be placed in the middle of existing floorboards to allow for possible expansion.
Every single type of timber flooring in Australia requires some kind of expansion allowance to prevent floor damage. However, the width, location, and frequency of these allowances varies based on the timber material, the product, the design of the room, and the width and length of the floor. So the best way to ensure well-installed, expansion-protected timber flooring is by following the manufacturer’s recommendations.
Despite this, it can be useful to have a basic understanding of the expansion differences between common floor types. Here’s our quick breakdown:
Timber flooring is popular in Australian homes due to its natural beauty, durability, and timeless…
Spotted gum is known for its stunning appearance and durability. Its rich, warm tones and…
Timber flooring is known for its natural beauty and durability, but it's also subject to…
In the colder months, timber floors may contract due to the decrease in temperature and…
Struggling to tell the difference between a belt sander and a drum sander? Not sure…
Transforming Merbau Timber Stair Treads with Non-Slip Loba 2-Pack Satin Finish: How to go about…