Granite decay and flaking

The case we are treating, it is a basement with granite walls over 200 years old, located in an enclosed area in a damp zone. Without outdoor exposure. In the following video we observe the granite breaking when passing the hand.

This type of degradation is caused by filtrations, ascendant capillarity, condensation by hygroscopic absorption, etc. The wall in these conditions, decomposes causing decay and flaking in the granite.

For the restoration and rehabilitation previously made, water repellents for waterproofing stone were used, also for avoiding the deterioration. The water repellents are only allowed to use over shady facades and just on non­degraded granite. They serve exclusively to correct the formation of mildew. In degraded granites, the repellent accelerates decomposition and consequent granite decay. The water repellents do not consolidate or waterproof the previously treated material, as they are only hydrophobic oils that repel water.

Consolidation is the most appropriate solution. The consolidation we use, in itself, does not waterproof degraded granite , but it produces the opposite effect to the granite decay. That means that it agglutinates the stone by structural bonding through the capillary network, with the addition of new salts to the granite.

Aquivigo performs the bonding with silica and aluminia salts dissolved into water. We consolidate the stone wetting and sealing the capillary network. In this regeneration of stone, salt intake is considerable and in the subsequent visual effect of the treated stone, it is possible to appreciate changes in color and appearance.

After performing the consolidation, it is necessary to perform complementary treatments to get the characteristic color of granite.