1. Preserves Natural Beauty and Color of Limestone
Limestone provides natural beauty that adds decorative quality to where it is installed. When a limestone sealer is used to coat the material, it will loose its natural color and look more artificial. Furthermore, sealers have a tendency to cause discoloration. Poor limestone sealer products cause the limestone to turn into a nasty yellowish color.
2. Preserves the Breathable Quality of Limestone
Unsealed limestone is breathable, meaning that it allows vapor to enter and escape its pores. When a sealer is applied, water may be repelled, but moisture may find its way into the pores of the limestone and escaping will not be easy. When moisture is trapped inside the stone, it increases the risk of damage. It can soften the stone and cause cracks especially when the temperature rises. However, an unsealed limestone will allow moisture to enter its pores, but will also allow it to easily escape, therefore decreasing the chances of damage.
3. Lessens Maintenance Costs
Limestone on walls does not really need to be sealed because it does not get in frequent contact with acids and other harmful contaminants. Therefore the cost is lessened because it does not require constant sealing. Remember that topical sealers need to be replaced every once in a while. If the limestone does get stained, it only requires a few natural cleaning agents to get the stain out.
In addition, some limestone sealers can be easily scratched because they are softer than the limestone itself. When scratch marks are produced in sealed limestone, this requires additional maintenance cost because the entire coating needs to be rebuffed or replaced.
4. It Makes the Limestone More Durable
Limestone in itself is durable. However, when treated with sealers, especially those that are permanent, it will require constant chemical treatment especially when the sealer needs to be replaced or removed. Constant chemical cleaning and sealer removal will definitely make the limestone more susceptible to damage.
5. Helps the Environment
Some chemicals used in limestone sealer products may have negative effects on the environment. Impregnators, for example, cause toxic vapors to be released in the environment after use.
Source: www.DoItYourself.com