Stucco with its distinct texture © Valiant Exteriors
The dividing line between stucco and plaster / rendering is vague, although stucco is more a decorative art. The name appears to derive from the Old German word ‘stück’ meaning ‘piece’ which evolved into the Italian word ‘stucco’.
Stucco is a composite of aggregates, water, and a binder that becomes a dense solid after being applied wet. Artisans formed it into shapes until quite recently. This was the basis of the ornate plastered ceilings that adorn mighty cathedrals and colonial city halls.
A Plaster Material with a Very Ancient Heritage
Archaeologists have discovered stucco reliefs among many ancient cultures. Some Egyptian, Minoan, Roman, and Etruscan work remains in good condition.
Decorative reliefs found their way into Islamic ornamentation. Baroque and Rococo architecture became rich with stucco during the Italian renaissance.
The great European mediaeval cathedrals were made from rough-hewn stones and bricks. Artisans covered the walls with marble or sandstone. Then they finished the ceilings with stucco decorations including dragons and saints.
Builders nowadays use a similar technique to cover over less attractive metal, concrete, cinder block, brickwork and adobe substrates. The traditional binding material was lime, until the introduction of portland cement in the late 19th century. Glass fibres and acrylics may be added to increase the strength of the bond.
Ancient and Modern Stucco Techniques
Traditional stucco work was a two- or three-part process. Artisans first applied one or two thin base coats to a wall. Then they topped this with a final layer tinted to the colour of the client’s choice.
Later, they developed a technique for covering a light timber structure with a wood lattice to support the wet plaster.
These laths are fitted over asphalt-impregnated paper, or felt on exterior walls to keep the damp where it belongs, outside. Nowadays the support work is a wire mesh.
This technique remains popular in Arizona, California, Florida, New Mexico, and Nevada.
Modern stucco (or exterior plaster) comprises a base coat and a thinner top coat. A plastic or wire mesh lath underpins it to resist movement or cracking.
However, premixed acrylic finishes are better able to stretch and bridge over cracks.
Tinted exterior plaster is a popular companion to siding in Canada, since it can be a long-lasting solution if correctly applied. However, it is almost impossible to ‘patch in’ repairs without overpainting afterwards.
Hence the need, as always, to find a reliable contractor for exterior building work in Calgary you can trust.