- Feb 7
- 4 min read

Problem of peeling facades and walls in San Miguel de Allende

Every year and season by season, San Miguel de Allende is painted in color with the palette of traditional colonial tones to give it the flavor of a magical Mexican town worthy of our pride and as a banner of colonial architecture.

Having our facades and interiors clean and painted in that mixture of wall, quarry, ironwork and tile, which contrast with the vegetation and an intense blue sky during the day and endless tones of sunrise and sunset, make San Miguel a dream that engraves in our minds.

Having a San Miguel de Allende like this costs us a lot. Year after year we paint and repaint our walls, knowing that it will not last one or two seasons and we have convinced ourselves to do it routinely.

Ancient techniques

To protect and paint the walls of colonial buildings in Mexico, a set of ancestral knowledge and practices that have been transmitted from generation to generation have been used. These techniques are based on the use of natural materials and artisanal techniques that have been adapted to the climatic and geological conditions of Mexico.

Some of the most common ancient techniques are:

• Whitewashing: It is a technique that consists of applying a layer of quicklime diluted in water on the surface of the wall. Lime has antiseptic and fungicidal properties that help protect the wall from moisture, mold and bacteria.

• Flattening: It is a technique that consists of applying a layer of lime and sand mortar on the surface of the wall. Flattening helps level the wall and give it a more uniform finish.

• Fresco paintings: It is a technique that consists of applying natural pigments mixed with water on the surface of the wall that is still fresh. The pigments bind to the lime and create a resistant and long-lasting paint.

• Plaster: It is a technique that consists of applying a layer of lime and sand mortar on the surface of the wall to protect it from the elements.

The problem

Today, ancient techniques are at a disadvantage because they require time because they are laborious in their application, in addition to being expensive because they use natural materials that can be more expensive than modern materials and require specialized labor with experience in their application.

Derived from the use of lime and mortar, as porous materials that turn out to be the basis of the ancient walls in San Miguel de Allende, having a colorful, clean and beautiful town pays a high price.

When painting the walls with wonderful colors from our colonial color palette, applied directly with lime base, inevitably the color and application will lose retention from one season to the next. The walls breathe, peeling off the color coating and even flattening it, exposing it to accelerated deterioration.

It seems that the solution is to paint and repaint every season or two to regain that bright image of traditional colors, resulting in expensive facade maintenance and ending up with colors that are not consistent in your image.

Is there a solution?

Paint on walls that peel off due to painting on walls with lime can be resolved by following these steps:

1. Remove old paint:

• Scrape the paint: A putty knife or scraper is used to remove as much of the old paint as possible.

• Sand the surface: A sander is used to remove traces of old paint and to smooth the surface of the wall.

• Wash the surface: The surface of the wall is washed with soap and water to remove dust and dirt.

2. Prepare the surface:

• Repair cracks: Cracks in the wall are repaired with a suitable mortar.

• Apply a heavy-duty sealant such as Loxon Conditioner, Kem Alkali, Pri- mer Rx, or similar. A sealant is applied to seal the surface of the wall and prevent the paint from absorbing.

3. Paint the wall:

• Choose high-performance paint such as Super Kem Tone Exterior, Bahía or water-based, limescale-compatible, weather-resistant acrylic glazes.

• Application: The paint is applied in two or three coats, allowing each coat to dry completely before applying the next.

In many cases it is not only a matter of coatings or reaching the base of the flattening, but it is necessary to analyze whether the walls require vents that help reduce the humidity that seeks to transmit through the walls, for example, in walls with gardens or planters in their walls. inner side.

By following these tips, you can prevent paint from peeling on your walls and enjoy a long-lasting finish with a better investment cost versus to repaint year after year.