The exterior wall of our grand room, as with so much of our house, clearly needs work. You can see the lime-based plaster has fallen away to expose the stacked stone construction. Stacking limestone rocks to form walls, called mamposteria, is the traditional building method in Mérida. It leads to thick walls about 1 1/2 feet that are incredibly durable over time.
The issue with these walls is the lime-based plaster expands in the humid climate, cracks and falls out. This is what leads to the gaping holes seen in the image above. The modern solution is to fill the holes with concrete instead of plaster. Concrete, lacking the lime, is not as susceptible to humidity and therefore lasts a lot longer.
