The Petry profile decouples the plaster from the window sill: easy to implement, it creates a clear edge in the reveal area and thus protects the plaster from tearing. The result impresses with a perfect optical result and a clean and long-lasting plaster finish.
Today's approach: Plaster edge directly plastered on the windowsill
The situation at the advanced house construction is always the same: the windows are installed, the windowsills are installed. Now it is time to plaster and paint. It often takes time and effort to achieve an optimal result with a clear edge in the transition area
from window sill to reveal. As a result, a serious problem can also occur: In the junction between the windowsill and the plaster, moisture can penetrate through hair-thin gaps – these are often caused by temperature fluctuations – and cause lasting damage.
The plaster becomes porous and begins to crumble. Countless examples bear witness to this annoyance, which is often only visible years later, and in the worst case, it can result in deeper structural damage to the facade.
Work quickly and cleanly with plaster finishing profiles
This is how it works better: with the special plaster finish profiles for interior and exterior window sills, the connection edges around the window sill can be plastered quickly, cleanly and safely and the decoupling between plaster and window sill can be established. The window sill can move freely with temperature expansion without damaging or cracking the plaster edge. The result: the transitions from the plaster to the reveal are perfect and the plastered plastic profile protects against the penetration of water into the plaster.
The L-shaped profiles are simply attached inside of the second sealing level to the left and right sides of the window sill where the plaster will end later. The profiles remain invisible in the wall. Vertical plaster and optional corner protection profiles can be connected to the plaster end profile without any problems. Then the interior or facade plastering can start directly - fast and precise plastering, which creates an accurate edge.
Depending on the specific situation, the window sill may optionally be removed and set aside for plastering and painting work: a perfect protection for the expensive component. There is no need for time-consuming masking of the window sill, and the plaster often breaks when the protective film is removed or fine gaps are created again - reworking would be the result. Another advantage that should not be underestimated: Without the disturbingly protruding window sill, the top plaster can be applied more easily over the profile edge, there is no need to clean around the edge. After plastering, the painting work will also be easier.
Outside, the precisely attached profile of the window sill is inclined accordingly so that no water can penetrate into the plaster in the transition area of the window sill for reveal. Consequential damage caused by bursting plaster is thus excluded in this area. In order to achieve additional protection against driving rain to the second sealing level, a sealing tape can optionally be attached to the shadow gap between the profile and the window sill.
The plaster finish profile represents a design variant of the decoupling between plaster and window sill required by the guidelines and regulations (e.g. the German GemRi2021 – “Gemeinsame Richtlinie Anschlüsse an Fenster und Rollläden bei Putz, WVDS und Trockenbau”). The transitions from the plaster to the reveal are perfect and the plastic strip that remains on the inside protects against moisture penetrating the plaster - for the optimal decoupling of any window sill, whether made of stone or aluminum, inside and outside. Water from heavy weather impact like driving rain which may penetrate the gap between profile and windowsill will safely be removed by the second sealing level below the window sill.
An optically excellent result also for inside sills
Indoors, there is often a situation where the plastering work is supposed to start, but the window sills are still missing - often the areas around the window sill that will be installed later have to be plastered later again. No problem with the plaster finish profile: after fitting the profiles, the plastering work can be carried out in one step, so that the window sill can be applied later.
The result inspires designer, builders and worker with a visually excellent plaster edge. The window sill is easier to be cleaned and could even be replaced later - if necessary - without damaging the plaster.
