Creating what is beautiful and preserving what is valuable with paints by KEIM.
Historical and technical challenges in the renovation of an old building
Those who understand that the past is the key to the present and future are aware of the significance of preserving and renovating historical buildings and protecting monuments. Preserving the architectural legacy of our predecessors for our children is the main concern of committed monument preservation and monument protection, and a great challenge for all those involved in renovating old buildings. The aim of such renovation work consists in the permanent protection and upkeep of monuments or historical buildings, preserving them from damage and other adverse effects. After all, future generations should also be able to enjoy the cultural legacy and historic past of buildings in their authentic form, due to this protection. When it comes to restoring and renovating old buildings, it goes without saying that the materials used must fulfil the highest quality requirements.
Restoration or renovation?
It is important to distinguish between these two terms, which are sometimes used indiscriminately. Restoration of buildings is about correcting structural defects and then increasing the value of the building through improvements, such as painting the facade. Restorers are dedicated to the same task, but in a more scientific way, preserving the architectural heritage without altering it. When finishing listed facades, an attempt should be made to respect the antiquity of the building and therefore to use compatible painting techniques that preserve the historical character. To this end, mineral paints without titanium dioxide can be used, or a final treatment with a glaze, which create surfaces with a certain depth and irregularity that reinforce the impression of authenticity of the facade.
"It is my aspiration to always be able to convey to future generations the unchanged splendour and beauty of the artistic creations as eloquent witnesses of the respective era."
(Adolf Wilhelm Keim, pioneer of silicate technology in 1881)
Our architectural heritage
The building techniques of past times were largely determined by the building materials available on site, and the surface design was influenced by the cultural aspects and trends of the time. As different as the techniques, materials and even tastes of antiquity were at different times and in different geographical areas, so too are the conservation and restoration criteria applied today. Conscious restoration means above all the greatest possible respect for historical materials. The Mediterranean region is the cradle of lime. It is traditionally used for both plastering and painting and has proven to be an excellent material for centuries. The exceptional compatibility and chemical reaction of silicate paint with lime make it a predestined material for the conservation and restoration of walls made of lime.
Lime and silicate - two that get on well together
Lime mortars suffer the effects of air pollution; the application of a silicate paint acts both as a strengthening agent and as protection against acid rain and fumes that attack the lime. In many areas there are special finishing techniques using lime mortar, which is often pigmented in the mass. The most common finishing techniques include bossing the surface, which imitates brickwork, or sgraffito, which involves layering different coloured plaster and then making incisions that reveal the hue of the layer below. Over the years, these plasters have suffered from natural ageing, dirt and colour loss. By applying silicate paints or mineral glazes, they regain the look of times past without losing their historic character.
There are also still numerous examples of decorative or artistic works on facades in fresco technique. They range from simple geometric drawings to the pretence of architectural elements to pictorial drawings, some of which are astonishingly complex. As with the plasters, the ravages of time have left their mark on these artistic expressions. In particular, we often find surfaces with partial loss of the plaster mass, which of course has also led to the disappearance of the surface. For the restoration or reintegration of these frescoes, the most compatible technique, similar in appearance, is again the application of silicate paints or glazes. They preserve the mineral character of the facade, perfectly reproduce the appearance of the fresco and allow restoration work with maximum durability and an ageing that is in no way inferior to that of lime.
What would a Baroque church be without its gilded decorations? Artisans of the time worked with gold leaf on iconic buildings such as cathedrals and palaces. On more modest buildings, mica was used to achieve a similar effect. Restoring these surfaces again faces the same economic dilemma as centuries ago. An elegant solution is the metallic shades of KEIM Design-Lasur, which are also suitable for exterior use.
Restoration in phases
The restoration of a building often takes place in several phases, often spread over a longer period of time. In the case of walls with historically valuable decorations whose restoration is only possible at a later date, a special product is needed that is capable of restoring the space without irretrievably losing the historical testimony. For these cases, there is KEIM Reversil - a reversible paint for the temporary protection of valuable paintings or decorations that can be removed later without damaging the work of art.
Monument protection – with KEIM Purkristalat, the original silicate paint
The materials used to restore and renovate listed houses and facades must fulfil the highest quality requirements.
Developed in 1878 by Adolf Wilhelm Keim, the originator of silicate technology, KEIM Purkristalat has been setting standards for durability, protection and fascinating colour brilliance for 140 years. Used predominantly for protecting historical buildings, KEIM Purkristalat enjoys favoured status among conservators and restorers and is often referred to as "church paint".
KEIM Purkristalat derives its unique quality from the perfect balance of its high-grade, exclusively mineral ingredients: inorganic, lightfast pigments, selected minerals as fillers and pure liquid potassium silicate as the binder.
But the "original silicate paint" owes its legendary reputation to the innumerable projects all over the world that, for generations, have impressively demonstrated what makes KEIM Purkristalat so unique: luminosity and vitality even after decades – facades that age with dignity.
Unsurpassed durability – monument protection with KEIM Purkristalat
KEIM Purkristalat, the pure, titanium dioxide-free silicate paint according to DIN 18 363 para. 2.4.1, remains firmly bonded with the substrate of the building facade over decades: the potassium silicate binder penetrates deep into the mineral substrate, where it reacts chemically. Known as "silicification", the result is an insoluble bond between paint and coating substrate, as in old buildings and other monuments. This bond is minerally sound and extremely durable. The purely mineral materials in KEIM Purkristalat are absolutely resistant to aggressive environmental influences, such as acid rain and UV radiation, and thus offer optimum protection. At the same time, the substrate is stabilised by absorbing the potassium silicate binder, thus becoming increasingly resistant.
Fascinating colour brilliance due to the purely inorganic binder
As well as its legendary durability, KEIM Purkristalat also owes its captivating appearance to the potassium silicate binder. The clear, purely inorganic binder allows light rays to hit the pigment particles on the monument directly, with unhindered light reflections that makes it look as if the KEIM Purkristalat coatings are actually shining. Combined with the brilliant luminosity of bright pigments, the natural effect of the mineral matt surface gives KEIM Purkristalat coatings an incomparable appearance – lively and fascinating.As well as its legendary durability, KEIM Purkristalat also owes its captivating appearance to the potassium silicate binder. The clear, purely inorganic binder allows light rays to hit the pigment particles on the monument directly, with unhindered light reflections that make it look as if the KEIM Purkristalat coatings are actually shining. Combined with the brilliant luminosity of bright pigments, the natural effect of the mineral matt surface gives KEIM Purkristalat coatings an incomparable appearance – lively and fascinating.
The alternative for monument protection: KEIM Unikristalat
When a historical building is being renovated, monument preservation measures are frequently caught up in the conflict between remaining as true as possible to the original building by using historical materials for reconstruction, and the scope of what is technically feasible. Often enough, this also applies to choosing a suitable coating system for monument protection.
Certain substrate characteristics, such as unstable renders or very thin render layers or slurries, may make KEIM Purkristalat unsuitable for the pending renovation. In this case, we recommend KEIM Unikristalat. The purely silicate-bonded, titanium dioxide-free facade paint has special potassium silicate as a binder that undergoes a process known as "fine silicification" to form a low-tension bond with the substrate. As a result, it can be used particularly for renovation work on weak renders or renders that are relatively thin.
Monument protection and monument protection law
Tip: Owners of buildings, houses, old buildings and monuments or historical buildings can contact the monument protection authority or the regional monument preservation authority to find out about funding programmes, renovation measures and legal aspects of monument preservation, in other words the monument protection law.
Are you renovating a monument and still looking for the right products for monument protection? Do you have any questions about our products for your house or building, old building, historical monument or generally about renovating old buildings? We are your partner for monument protection. Send us an e-mail or give us a call!