real estate

The Cornerstone - Filling in the Cracks

By Daniel Steinkoler

October 2008

Twenty years ago I started in the painting and plastering business.  Small paint and plaster repair jobs led to larger jobs, which eventually led me down the path to becoming a custom builder and high end remodeler. Learning the painting and plaster trade in a high end market such as Georgetown required an understanding of the exact methods and materials used by the original artisans. This knowledge would be essential for my crew and I to perform repair work correctly. As most of our DC homeowners are currently residing in these older homes, I would like to take a quick step back in time in order to help us understand a bit more of the character and history of these residences.

To begin with, plasterers in North America have relied on two basic materials essential to their trade, these being Lime and Gypsum.  Until the end of the 19th century, plasterers used something called lime plaster.  The lime came from either ground and heated limestone, or, believe it or not, crushed oysters, the aggregate from sand and the fiber from hogs hair or cattle hair. The hair served as a binding agent for the ingredients, hence the name horsehair plaster was used to refer to this original material.  With manufacturing advancements in the early part of the 20th century, gypsum became a plastering material on its own, although lime plaster and gypsum plaster were used in conjunction through the early 19th century.  It was Gypsum that was to become more widely used and eventually took over as the material most used in plaster work. The primary difference between the two was that gypsum did not contain a fibrous binder and was more vulnerable to water damage.  Also, gypsum required an air gap between the masonry substrate in order to protect itself against moisture.  Therefore, homes built after the early 1900’s would be characteristic of a lime plaster applied directly over the substrate material. Conversely, homes built after the early 1900’s would contain gypsum plaster on a wood lath base.

Most older homes in DC contain either of these two wall systems or a combination of the two. Once demolition begins it is possible for an experienced contractor to ascertain whether the original horsehair plaster is present versus the early 20th century gypsum lath.  By examining the type of plaster, we can literally dissect a house and go back in time to see when updates and repair work were completed.

Although current day materials have been modified to suit today’s market, many of the old world methods of plastering still exist. Gone are the days of using hogs hair or horsehair as a binding agent. Curing times are now considered in days versus weeks, allowing for quicker application of finishes. With the advent of gypsum board, most new construction and remodeling is geared toward lower costs and more timely completion schedules. However, the homes of old still exist and so do those of us who have a passion to work on them. Oftentimes historical restorations and large scale repair projects will require these old school techniques be performed in a modern day setting.  These projects create an opportunity to bring the distant past back to life and are usually the most interesting and fun to work on. 

Please feel free to contact Daniel at info@superiorhomeservicesinc.com should you have any comments or questions.

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