Is Tile Waterproof? The Definitive Answer for Homeowners

It’s one of the most common questions we get at Erskine Floors & Interiors: "Is tile waterproof?" The short answer is yes, with some important caveats and details that every homeowner in Maplewood, MN, and Western Wisconsin should understand. 

 

When you choose tile, you are essentially selecting a defense system against water, making it the preferred material for kitchens, bathrooms, laundry rooms, and any area prone to moisture. However, the waterproof performance of your installation relies on more than just the tile itself—it involves the entire system.

 

The Tile Itself: Waterproof vs. Impervious

 

To truly answer the question, "Is tile waterproof?" We must distinguish between the two primary categories of tile: ceramic and porcelain.

 

Porcelain Tile: Truly Impervious

 

Porcelain tile is made from a highly refined clay mixture and fired at extremely high temperatures. This process results in a tile that is dense and has a water absorption rate of 0.5% or less, as defined by the American Society for Testing and Materials (ASTM).

 

• The Verdict: By industry standards, a tile with a water absorption rate this low is considered impervious—meaning it is virtually waterproof. Water simply cannot penetrate the body of the tile, even when submerged.

 

Ceramic Tile: Water Resistant

 

Ceramic tile is made from a coarser, less dense clay mixture and is fired at lower temperatures. It typically has a higher water absorption rate than porcelain (often 3% or higher).

 

• The Verdict: Ceramic tile is highly water resistant, especially when finished with a durable glaze. The glaze acts as a non-porous barrier, but the unglazed body beneath can absorb some moisture over time if exposed. For this reason, glazed ceramic is excellent for walls and backsplashes, but porcelain is the safer choice for floors in very wet environments like shower pans.

 

The Essential Role of Grout and Installation

 

While the tile itself may be impervious, the installation components are the weak link in the system. The complete answer to "Is tile waterproof?" depends on the following two elements:

 

Grout: The Porous Component

 

Grout, which is used to fill the spaces between tiles, is a cement-based material that is inherently porous. If left untreated, water will easily seep through the grout lines and penetrate the subfloor.

 

• The Solution: To ensure your entire tile floor is waterproof, the grout must be sealed immediately after installation. Grout sealants fill the microscopic pores, repelling water and resisting stains. For maximum protection, epoxy grout is a non-porous alternative that never requires sealing, making it the highest standard of moisture defense.

 

The Substrate and Underlayment: The True Barrier

 

In a shower or bathroom, the true waterproof barrier is not the tile or the grout—it’s the underlayment system installed beneath them. Professional tile installations in wet areas require specialized waterproof membranes or backer boards that completely shield the subfloor from water damage. Even if water permeates the grout, it hits this membrane and is routed away.

 

• The Importance: When you choose tile, you’re investing in a waterproof system. A proper installation by the experts at Erskine Floors & Interiors ensures the correct membranes and sealants are used to achieve a truly waterproof result, preserving the structural integrity of your home.

 

Porcelain tile is the closest material to being truly waterproof on its own, but achieving a completely waterproof floor or shower relies on using high-quality grout sealants and a properly constructed waterproof membrane beneath the entire installation.

 

Remodel Your Bathroom with the Experts at Erskine Floors & Interiors Serving Western WI

 

If you are planning a bathroom remodel or a kitchen update and need the assurance of a water-resistant, durable floor, tile is the answer. For almost 40 years, Erskine Floors & Interiors has built a reputation based on quality materials, professional installation, and personalized customer service for all types of residential and commercial projects, ensuring your tile installation is executed perfectly.

 

Call us or Visit us at our showroom location in Maplewood, MN, servicing the areas of Western Wisconsin, to speak with an expert about your tile needs and confirm your installation will be completely waterproof.