Facades painted using elastic paintings

Some of the existing solutions for waterproofing monolayer facades are not as effective as we think they are. Monolayer coated facades are often covered with elastic paint to try to solve the filtration problems.

In facades coated with such paint, it usually appears blisters because of the sun action. Moreover, due the called “Vapor barrier” happens the mortar degradation, a characteristic problem in facades with waterproof paints.

It is common to see buildings with concrete facades repainted with elastic waterproof paint over rigid waterproof paint. This practice is not recommended because the solar radiation heats the wall, taking off the initial layer of paint, causing chipping.

In this picture you can see how the elastic red paint comes off of the initial layer of white paint.

In this picture you can see how the elastic red paint comes off of the initial layer of white paint. In other facades can be seen how the paint over the coated monolayer does not prevent the rainwater filtration, but the rigid waterproof paint prevents water to go outside. Consequently, the coated detaches by carbonation of mortar and it breaks..

This photo shows the lamentable state of the wall, with a high risk of detachment.

It is important to pay attention to this phenomenon as it is causing the paint peel off the wall. An example of facade carbonation can be seen in the following image, initially the facade had a rigid acrylic paint and after it was repainted with an elastic paint. The carbonation front occurs within 1 cm from the painted surface, a complete destruction of the mortar can be noticed..

An oxidation of the armor will occur also, as the corrugated iron rods are protected against corrosion by the alkaline PH of the mortar. This alkaline environment is destroyed by the reaction of atmospheric carbon dioxide with the lime mortar, when this process reaches the iron rod, the reinforcement corrosion begins to happen.