Cleaning and maintenance of Silicone Construction Sealants

In response to the many requests we receive regarding sealant maintenance and cleaning procedures for silicones in general United Professional offers the following comments.

Silicones have been used in your quality building project because of their stable properties regardless of environmental conditions. Therefore, cured silicone sealants in weatherproofing joints or remedial repair joints do not require cleaning in order to functionally perform as a weatherseal. However, the joints may become dirty and it is desired by a building owner to clean them for aesthetic reasons. This can be accomplished during regular building washing that may occur annually; or it could be a scheduled maintenance event specific to cleaning the sealant. How often this is required is a decision for the building owner, and will be influenced by building location and the environment around the building. In general, Unipro would recommend an annual cleaning procedure if desired to maintain peak aesthetic appearance.

A mild detergent and water solution will remove any dirt and most rundown materials from the sealant,  Examples of detergents could include, but not be limited to:

Simple Green and TSP, which are commonly available at hardware stores. A solution using a mild detergent and water could be sprayed on the joint if the building were being pressure washed anyway, and then the dirt from the surface can either be sprayed away or brushed away with a soft bristle brush.

Testing or a mock-up would assist in determining if a brush is necessary. Soft bristle brushes with yellow bristles, available at hardware stores, have been found to work well. Sometimes the label on the brush reads “acid brush.” You could also choose to clean the joints individually; in which case the excess dirt and debris should be brushed away; then a detergent solution could be rubbed on; and then this solution should be wiped away with a clean rag. Again, the soft bristle brush could be used to loosen dirt which did not easily release.

In order to lessen the amount of materials required, it has also been found that the cleaning sponges that are pre-soaked with a detergent work well in cleaning stains from silicone surfaces. Examples are the “Mr. Clean” pre soaked sponges. It would still be recommended to remove any excess dirt or

debris from the sealant surface first; then if there are spots remaining, the pre-soaked sponges can be used at those areas to further clean the surface.

If the sealant is cleaned using pressure washing during a full building cleaning,

Unipro recommends that a mock – up area be tested in order to determine the psi required that will clean the sealant without damaging it. Sealant manufacturer’s warranties do not cover damage caused by water spray. Sealant joints and designs are unique to each building project, so the best way to proceed with pressure washing is to test small areas prior to cleaning the entire building. A starting point would be 1500 psi, fan blade, and a distance of 6-8” from the joint. Wheels from swing stages are not recommended to ride on the sealant.

Please feel free to contact us should you have any concerns regarding weatherseal maintenance.