The Importance of Perm Ratings when Choosing a Waterproof Membrane for your Stone Shower

By Frederick M. Hueston  StoneForensics.com

A waterproofing membrane is an essential component when it comes to building a stone shower. The right membrane can ensure that water does not seep through the tile or stone, preventing water damage and potential mold growth. However, when choosing a waterproofing membrane, it is crucial to consider the perm rate of the product. In the following I will discuss the importance of perm rate when choosing a waterproof membrane for your stone shower.

What is Perm Rate?

Perm rate, short for permeability rate, is the measure of a material’s ability to allow water vapor to pass through it. In the case of waterproofing membranes, perm rate is an essential factor to consider as it affects the moisture transmission rate. A material with a low perm rate indicates that it is less permeable, meaning it is less likely to allow water vapor to pass through it.

Why is Perm Rate Important for Waterproofing Membranes?

The perm rate of a waterproofing membrane is a critical factor in preventing moisture buildup in your stone shower. When moisture accumulates in the shower, it can lead to a range of problems, including mold growth and water damage. In contrast, a membrane with a high perm rate can allow moisture to escape, reducing the risk of these problems.

A waterproofing membrane with a low perm rate may seem like a good choice as it appears to be more effective at preventing water from seeping through. However, a membrane with a low perm rate can also trap moisture inside, leading to problems like mold growth and water damage. Therefore, it is essential to choose a waterproofing membrane with a balanced perm rate that can prevent water from seeping through while allowing moisture to escape.

Factors that Affect Perm Rate:

Several factors can affect the perm rate of a waterproofing membrane, including the thickness of the material, the type of material, and the installation process. For example, a thicker membrane may have a lower perm rate, while a thinner membrane may have a higher perm rate. Additionally, the type of material used in the membrane can also affect the perm rate. For example, some materials may be more permeable than others.

When choosing a waterproofing membrane for your stone shower, it is essential to consider the perm rate of the product. A membrane with a balanced perm rate can prevent water from seeping through while allowing moisture to escape, reducing the risk of water damage and mold growth. Additionally, it is important to consider other factors that can affect the perm rate, such as the thickness and type of material used in the membrane. By considering these factors, you can select a high-quality waterproofing membrane that will protect your stone shower for years to come.