Monday, June 13, 2011

VARIATIONS IN SMOOTH FINISH

Sometimes architecture calls for variations in the finish of steel troweled stucco. There is hump and bump”, “cat-faces and differing degrees of imperfections like trowel ridges, burns and mottling. It is important to use these variations correctly. I am convinced that by the time the actual applicator is doing these finishes he has no idea why he is doing it that way. The concept may come from the owner or architect. It may be an early California or Mission Finish. “Hump and bump “is a look that has impressions and protrusions in the wall. This is actually done in the brown coat as it takes many coats to build up the humps in the wall. This look is supposed to replicate plaster being applied many times over decades. Therefore, it is critical the architecture be historic and not modern. The job should also not be painted. Cat-faces are the small voids that are left open between the first and second coats of smooth stucco. They should be irregular in shape and random. This look is supposed to show stucco so old and from local materials that they fall off the wall over time. Sometimes brick is applied on the corners to show how the stucco has fallen off the original brick substrate. Again, if these voids are consistent and not placed randomly it looks terrible. As in most construction problems the issue comes from poor communication. The architect and owner agree on a certain look and should describe it properly and ask for a mock-up in the construction documents. The general contractor should insure the plastering contractor understands what is required and properly conveys this to his applicators. This is a long chain to describe a possible story about an “early California” look. It some cases the owner is calling for a job the applicator deems to be imperfect and below his skill level. Therefore a large mock-up should be mandatory if either of these alterations is desired. I would encourage architects and owners to not use these textures unless there is a willingness to be diligent in overseeing this process.

Hump and Bump Finish

Catface Finish

If we have learned anything from our friends in Italy it is to let nature take its course. When they show samples of plasters they are fairly even and consistent.  They know that time will take care of the look that is desired. We want to use trowel burns and friction to replicate the aging process to make it look old when the project is just completed. It is certainly more natural if we let time take over and let our natural products age, crack, mottle and do all the things that finishes do in Venice, Tuscany and other historic places to show the enduring beauty of natural cement and lime stuccoes.

Old World Finish