HPC of South Bend and St. Joseph County - Standards Update Draft

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City of South Bend and St. Joseph County Historic Preservation Guidelines 90 For More Information: Paint • Have paint samples analyzed when possible . Paint analysis can help you determine appropriate colors for repainting . • Do not strip paint from metals that require protection from the elements . Likewise, do not paint metals like copper, stainless steel or bronze that are not meant to be coated . Properties of Paint Exterior Paints Paint is one of the most common ways to protect exterior materials, particularly wood, without natural or chemical preservatives . When the painted surface has been compromised, moisture infiltrates the underlying material and potentially accelerates deterioration. Oil and Latex Paints There are two different types of readily available paint for a building—oil and latex. They both consist of three principal components: a pigment, a binder to adhere the pigment to a surface as the paint dries and a solvent that makes the mixture loose enough to apply with a brush. Even though latex was developed in the mid 1940’s, oil was the dominant paint type until about 1970 and is found on many historic buildings today . Oil paint generally adheres better to problem surfaces because the oils are small enough to seep into the wood or microscopic openings in old, even chalky paint . Latex paint is less likely to peel from a building with excessive interior moisture, although multiple layers of paint can create an impermeable moisture barrier . Because of oil paint’s adhesion properties and the fact that multiple layers of latex paint form an impermeable moisture barrier, oil-based paint is recommended for exterior woodwork surfaces. Stains Exterior stains are typically applied to wood and generally fall into one of two categories, semi-transparent and opaque. Semi-transparent stain, generally known as varnish, allows some or all the wood’s color, grain, and texture to show through, and was historically limited to doors. Semi-transparent stain tends to deteriorate quickly in the elements and are generally not recommended. Historically, their use was limited to main entrance doors protected from the weather . Opaque stain provides a consistent color finish allowing more surface texture than paint. Opaque stain appears like paint; however, a stain weathers differently than paint because it does not build up into a thick film that can peel off. Rather it slowly fades when exposed to weather conditions, particularly when exposed to direct sunlight . Because opaque stain needs to penetrate wood to bind, ideally it should be applied to clean bare wood and limited to a small wood site element, such as a fence, gate and/or shed . Specialty Paints Elastomeric or Encapsulating Paint Use of encapsulating paint is problematic because it can trap moisture in woodwork, promote rot and/or provide a desirable environment for pests such as termites . It is often referred to as “liquid siding,” “liquid stucco” or “liquid ceramic coating” . Use of encapsulating paint is not permitted . Metal Paint The paint selected must be compatible with the type of metal and existing coatings . When painting, metal preparation should include the removal of rust to bare metal, cleaning the surface and quickly applying a rust- inhibiting primer to prevent corrosion. Wood Graining Exterior wood that appears to be stained is often wood grained, using primer and multiple layers of glazes that have been textured to im- itate wood, particularly rare and costly wood. Graining was common in the 19th century and is most often applied to front entrance doors.DRAFT