Back To Schedule
Saturday, June 1 • 2:00pm - 2:30pm
(Architecture) Façade Cleaning: Managing Expectations

Sign up or log in to save this to your schedule, view media, leave feedback and see who's attending!

The success of a facade cleaning project should be measured not only by how clean the building looks after the project has been completed, but also whether cleaning has been sufficiently gentle to avoid damaging the substrate. In fact, a building may appear strikingly clean and “like new” because it has been over-cleaned and damaged during the cleaning process. However, a facade cleaning project that has been sufficiently gentle to remove only a portion of soiling and staining may be considered a failure if the results are not clean enough to meet owner expectations.

Inappropriate and overly aggressive cleaning, with the wrong products or techniques, may permanently damage the substrate, as well as other building elements and site features. Depending on the cleaning system used, and the damage that may have occurred, over-cleaning can also result in increased repair and maintenance needs in the future. However, it may not be easy to define what constitutes damage in a cleaning project, or to convince the owner that damage has occurred.

Almost any cleaning system can result in damage to some substrates, if not properly tested, applied, and controlled. Some fragile materials can be eroded by water cleaning, and the presence of even a very small amount of iron in the water used for cleaning and rinsing processes can result in staining on some substrates. Microabrasive cleaning systems require very careful control to provide appropriate results without damaging the surface. Chemical cleaners in particular can be subject to misuse; material safety data sheets (MSDS) provide information on chemicals that are hazardous to people rather than chemicals that may be hazardous to building substrates. Aggressive chemicals such as hydrofluoric and hydrochloric acid, which are present in many proprietary cleaning products, can damage facade components, mobilize staining, and are also hazardous to persons, animals, and the environment. Even less aggressive chemicals, such as organic acids contained in some proprietary cleaners, may react with certain minerals in masonry substrates and cause staining.

Although conservators and others in the preservation professions would agree that treatments that cause damage to the historic materials should not be used, once a building owner has seen a bright, clean, trial cleaning sample, how can we convince the owner that the cleaning method that resulted in a like-new appearance is not an appropriate solution? This presentation will examine a range of cleaning systems and potential effects on substrates, and consider possible approaches to guiding the building owner to an appropriate decision. Techniques for facilitating discussion and managing expectations include educating the client from the very beginning of the cleaning project; providing a range of trial samples to illustrate potential results (and avoiding trial samples with overly aggressive cleaners); being prepared to illustrate the effects of cleaning systems with examples and by microscopic evaluation before and after cleaning; and emphasizing the benefits of responsible cleaning and the positive aspects of a building that may be less clean—but is more sustainable for the future.


Deborah Slaton

Principal, Wiss, Janney, Elstner Associates, Inc.

Saturday June 1, 2013 2:00pm - 2:30pm EDT
JW Marriott 103-104 19 S West St Indianapolis, IN 46204

Attendees (0)