Preparing the support for decorative frames and cornices

Preparation begins with a thorough inspection of the ceilings and walls . Around the perimeter, where profiles, brackets, or cornices will be attached, the plaster is checked for soundness: no swelling, no hollow sound when tapping, no flaking paint. Any damaged areas are removed, re-plastered, and smoothed to create a solid base.

The angles between the wall and the ceiling are also checked geometrically. Significant out-of-squares or significant differences in height require corrections: sometimes it's preferable to work with cornices that visually "rectify" the perimeter, other times it's necessary to smooth out irregularities as much as possible before applying frames and profiles. This step is particularly important in modern spaces, where lines and grazing lights highlight every difference.

For plasterboard cofferdams , preparation includes defining solid anchor points in the ceiling and walls. Suitable anchors are used on brick and concrete floors; on existing plasterboard structures or suspended ceilings, it is often necessary to intercept the metal substructure or provide additional reinforcement. A cofferdam designed without considering where its weight will be placed is likely to crack or vibrate over time.

For adhesive frames (polyurethane, polystyrene, glued plaster), cleaning the substrate is essential. Dust, grease, old glossy paint, or thick enamels drastically reduce adhesion. Therefore, it's important to lightly sand the contact areas, remove any dust, and, if necessary, apply a primer or fixative compatible with the glue used, before proceeding with gluing.

If there are electrical systems, roller shutter boxes, pipes , or other interferences along the perimeter of the ceiling, preparation includes mapping them and, if necessary, moving them or integrating them into the design. It's not enough to simply "cover" them: you need to know where the cables run, where future light fixtures will be located, and how to access any components that need to be inspected.

Finally, for environments subject to humidity or movement , such as attics, bathrooms, or older buildings, preparation involves assessing the risk of microcracks. The use of reinforcing tape, elastic fillers in the joints, and appropriate paint systems reduces the likelihood of cracks appearing along the edges of cornices or cornices after a short time.