Granite is one of the hardest and densest natural stones available, making it a champion of durability in the kitchen. While granite is highly resilient, it is important to understand the relationship between granite, water, and the protective sealant that keeps your countertops looking flawless. The good news is that water cannot structurally damage granite, but it can certainly affect its surface appearance.
At JRL Granite & Marble, we educate our clients on how to protect their investment through proper sealing and routine maintenance.
Can Water Actually Damage Granite?
The key distinction lies between the stone itself and the finish (sealant) applied to the stone.
Granite Itself Is Not Damaged by Water
Granite is formed under extreme heat and pressure, making its crystalline structure incredibly resistant to moisture. Unlike wood, laminate, or concrete, granite will not warp, swell, or structurally weaken when exposed to water.
But Prolonged Exposure Can Stain or Darken the Stone
While the stone remains structurally sound, water can penetrate the microscopic pores found in unsealed or poorly sealed granite. When water remains on the surface for a long time—such as a glass left overnight—it can be absorbed, causing the granite in that area to appear darker or cloudy. This is technically a stain, but it is typically temporary, as the water will eventually evaporate.
Sealant Breakdown Can Cause Moisture Absorption
The sealant is the true line of defense. The primary function of a sealant is to clog the stone’s pores, creating a barrier that prevents liquids (especially oil and water) from soaking into the material. If the sealant wears down in high-traffic areas, like around the sink, the granite becomes vulnerable to water absorption.
Common Water-Related Problems
These issues are surface-level and easily manageable, but they signal that your granite needs attention.
Dark Spots That Appear After Spills
If you spill a glass of water and the area remains darker than the surrounding stone after a few minutes, this is a clear indication that the sealant has failed or is absent in that area, and the granite is absorbing moisture.
Hard Water Marks
In areas with high mineral content in the water, splashes and drips around the faucet can leave behind crusty white or light gray rings. These are mineral deposits, not damage to the granite itself, and can be gently cleaned off (see maintenance section below).
Mineral Deposits Around the Sink
This is a very common issue where water frequently pools near the faucet base or the sink edges. The constant evaporation of hard water leaves behind mineral residue, which can sometimes appear as a faint, crusty residue that needs regular cleaning.
How to Prevent Water Stains on Granite
Prevention is straightforward and centers on protecting the porous surface with a barrier.
Regular Sealing
This is the most critical preventative step. Depending on the granite type and kitchen usage, resealing is generally required every 12 to 18 months. Always use a high-quality penetrating stone sealer.
Using Dish Mats or Drying Racks
Never leave wet dishes, sponges, or dishcloths directly on the granite, especially near the sink. The constant standing moisture will quickly break down the sealant in that localized area. Use a dish mat or drying rack to provide an air buffer.
Wiping Standing Water Near Sinks
Make it a habit to wipe down the area around the faucet and the sink edge after washing dishes. This is where most water absorption issues begin due to continuous exposure.
Fixing Existing Water Damage
Temporary dark spots caused by absorbed water are usually repairable without professional intervention.
Removing Water Rings
If absorbed water has darkened the stone, the solution is patience. You must allow the moisture to fully evaporate. You can speed this process up by placing a fan near the area for several hours or by gently warming the area with a hairdryer set on low heat (be cautious not to overheat the stone).
Polishing Surface Haze
If the water damage is actually a haze or dullness caused by mineral buildup or harsh cleaners that damaged the sealant, you may need a specialized stone cleaner or a mild poultice (made of flour and diluted hydrogen peroxide) to lift the residue.
When Professional Refinishing Is Required
If the spot remains dark after 24–48 hours of drying, or if the surface is noticeably rough, scratched, or etched (which can happen if a cleaner was too acidic), the issue is beyond simple cleaning. Professional honing and re-polishing by a stone expert will be required to strip the damaged surface layer and restore the granite’s original finish.
FAQs
“Why does granite turn dark when wet?”
Granite turns dark when wet because the water fills the microscopic air pockets (pores) just beneath the surface. The change in light refraction makes the stone appear deeper and darker in color. If the stone is absorbing water, it means the protective sealant has failed.
“Can unsealed granite absorb water?”
Yes. Unsealed granite is naturally porous and will readily absorb water. This is why sealing is a mandatory part of the installation process. If a granite slab remains unsealed, it is highly susceptible to staining not only from water but also from oils, wine, and coffee.
“How long does it take water to evaporate from granite?”
If the stone is properly sealed, water should not be absorbed at all. If the granite is unsealed and water is absorbed, it can take anywhere from a few hours to a few days to fully evaporate, depending on the granite type (some are denser than others), the amount of water absorbed, and the ambient humidity and airflow in the kitchen.
Protect your granite and ensure its lifetime beauty with expert sealing.
Contact JRL Granite & Marble today for a sealing consultation or to inquire about our professional repair and refinishing services.