The first reason: Users do not follow the instruction of the providers such as cleaning the stains with appropriate cleaning products as soon as they appear (grease stains caused by coffee, tea, food, cosmetics, ballpoint pen ink, fountain pen ink, paint, mold, lichen ...) or do not perform periodic polishing.

The second reason: Quality of natural stone products and installation services is not good. For example, natural stone is not well impregnated prior to installation or types of natural stones are not suitable for work items. These factors have great influence on the final quality of each category. Therefore, the evaluation and selection of products and services suppliers is the first important step to achieve the required quality and aesthetics.

The fourth reason: Wrong way of care and maintenance. Big projects (hotels, office building…) can either wrongly self-execute or hire industrial cleaning companies. Most of industrial cleaning companies do not have specific products for natural stone. In addition, they may not have deep understanding of natural stone to implement suitable treatment and proper maintenance. This may lead to a deterioration of natural stone in many cases.

The fifth reason: The stains are a natural character of natural stone. In other cases, stains may appear as water, which contains minerals, evaporates and leaves yellow streaks. if not clean on time then these streaks will become stains which are very difficult to clean.