The short answer is “no.” think of the most common use for cork, wine stoppers. cork has been used for wine stoppers for hundreds of year primarily because it does not absorb water or liquids. Cork has also been used for years in buoys, life jackets and other floatation devices, again because it does not absorb water and can remain buoyant for years.
A cubic inch of solid cork immersed in water for 48 hours will gain less than 3% in weight due to water absorption. A cubic inch of solid wood or unglazed clay-bodied ceramic tile would gain many more times this percentage in weight of water if immersed for 48 hours.
Is cork resistant to water?
Think about it: natural cork kept sea water from ruining the champagne that was salvaged from the Titanic. that’s enough to prove cork is naturally water resistant, it’s why there is a wine-cork industry.
Cork is one of the oldest materials known to man with decent resistance to water, and used by man as an insulator. It is also one of the handiest items on the planet and is used in a wide variety of situations. Cork was trusted to protect people against temperature and elements of weather as well as moisture and humidity. In fact, since it has decent natural insulation properties, it’s currently used as a form of heat insulation in space shuttles.
Is cork waterproof? Will cork absorb water if it gets wet?
Unfortunately, cork is not fully waterproof and is better classified as an excellent water-resistant material. this is because cork absorbs some water or liquids when it’s exposed to water for a long time.
If you leave a cubic inch of a solid piece of cork immersed in water, it’ll eventually soak up water and increase in weight. The weight gain isn’t huge and is usually limited to about 3 to 5%. This means that cork is a pretty excellent insulator when it comes to water resistance and does a much better job than hardwood flooring and similar natural alternatives.
How long can cork last in direct contact with water?
After some time in the water, you should expect the very tiny gaps in the cork to soak up the water and swell.
However, since the amount of water absorbed is so little, the dimensions of the piece of cork stopped might not be affected.