There have been a number of recent advances in paint and finish technologies which offer exciting new façade design possibilities, according to Gary Bundy, Technical Director, Sto UK. One such advance borrows technology from nature, using a special composition of binding agents and filler material to recreate the micro textures found on the shell of the fog-basking beetle.
The micro textured surface of this façade paint simultaneously repels water and channels it away, allowing the façade to dry out rapidly. Micro-organisms have very little opportunity to grow and the risk of the surface staining is dramatically reduced. This new façade paint also accommodates design considerations with a wide choice of colours available, providing great colour stability and offering a huge design potential.
Modern technology can help keep façades clean in the form of a dirt-removing façade paint which recreates the natural self-cleaning effect of the lotus plant. The “lotus-effect” forces the rainwater to run off in droplets, and remove dirt particles from the surface in the process. Water and dirt are prevented from clinging to the surface, and this keeps the façade looking clean and attractive far longer than a conventional finish.
Today’s façade paints can also play a major part in the design process, with the availability of new colour options. For example, it has traditionally been impossible to add a very dark render finish over external wall insulation, as the render absorbs solar heat, reaching temperatures of up to 80°C and causing cracking and dimensional instability.
However, now some modern façade paints eliminate this problem by using special black pigments that reflect much of the solar energy in the invisible near-infrared spectrum. This means that even a dark colour will remain cool, protecting both the render itself, and the insulation underneath, from the extremes of thermal stress. In effect, this removes almost all the thermal limits which have previously governed the use of dark coloured render in façade design.