Why do I have Brown Spots on my Granite and how do I remove them?
2 thoughts on “Why do I have Brown Spots on my Granite and how do I remove them?”
Sam says:
A brown stain appears on the top surface of granite grouting joint newly completed & not occupied for 7 months (Brand new). Installer cleaned it away. Gradually the brown stain spread along the joint reaching the bottom of vertical grouting joint. Visually, the interfacing gap of 2 slabs of granite has no seal applied to it. Eventually, below this brown stain vertical grouting line, the top surface of cupboard is damaged by brown colour liquid. On 2 occasions, contractor just clean away the stain without reinforcing the grouting joint.
I suspect the interfacing gap of granite slab without seal is trapped with water during cleaning using damp cloth. This accumulated trapped water eventually drip to the cupboard below & cause water damage after moving in for 8 months. Granite specialist claimed that water was allowed to flow beyond the edge of granite worktop but the rest of bottom cabinet & footing of cabinet is fine & floor is not damage. The cabinet & cupboard below the granite worktop is built sunken-in & how water got landed on top surface of cupboard? I wish I could attach pictures for reference.
What can cause this problem.
I’m not sure I fully understand your situation. Normally slabs of granite would have the joints filled with an epoxy and silicone or polyurethane sealant to make the joint water tight. Particularly if the joint is a transition joint like the inside joint between to adjacent walls.
If you have a cementitous joint then some grouts can bleed stains when they get wet. Or a contaminate can absorb into the grout joint and diffuse or migrate into the adjacent areas. Water is the carrier of stains. So if you can prevent water from migrating into the joint that might or might not fix the problem. Just depends on what is the problem.
A brown stain appears on the top surface of granite grouting joint newly completed & not occupied for 7 months (Brand new). Installer cleaned it away. Gradually the brown stain spread along the joint reaching the bottom of vertical grouting joint. Visually, the interfacing gap of 2 slabs of granite has no seal applied to it. Eventually, below this brown stain vertical grouting line, the top surface of cupboard is damaged by brown colour liquid. On 2 occasions, contractor just clean away the stain without reinforcing the grouting joint.
I suspect the interfacing gap of granite slab without seal is trapped with water during cleaning using damp cloth. This accumulated trapped water eventually drip to the cupboard below & cause water damage after moving in for 8 months. Granite specialist claimed that water was allowed to flow beyond the edge of granite worktop but the rest of bottom cabinet & footing of cabinet is fine & floor is not damage. The cabinet & cupboard below the granite worktop is built sunken-in & how water got landed on top surface of cupboard? I wish I could attach pictures for reference.
What can cause this problem.
I’m not sure I fully understand your situation. Normally slabs of granite would have the joints filled with an epoxy and silicone or polyurethane sealant to make the joint water tight. Particularly if the joint is a transition joint like the inside joint between to adjacent walls.
If you have a cementitous joint then some grouts can bleed stains when they get wet. Or a contaminate can absorb into the grout joint and diffuse or migrate into the adjacent areas. Water is the carrier of stains. So if you can prevent water from migrating into the joint that might or might not fix the problem. Just depends on what is the problem.