Plaster walls show an older building is of substantial character. Plaster walls are constructed using a four-part system. First, strips of woods called lath are nailed horizontally to the upright structural members of the wall’s framing.
This lath is spaced approximately ¼” apart. When the first coat of plaster called the scratch coat is coated over the lath, much of the plaster is forced between the spacing and enters the openings and clings to the roughened surface of the backing lath, locking the scratch coat to the lath. The plaster locking the brown coat to the back of the lath is called the key. Over this, scratch coat is applied to the brown coat, followed by the finish coat of plaster called the white coat.
If either the lath or brown coat have suffered damaged, it is probably more cost effective to remove the plaster wall completely and install drywall in its place. If only the white coat is damaged and the brown coat is in good repair it is probably more cost effective to repair using either patching plaster or joint compound. If the building has been well heated over the years, the walls will probably be in good repair and may not require anything more than some patch plastering and a good painting.
However, if the building has not been heated for some time or has been exposed to the elements, there is a good chance that spider cracking, surface, or sub-surface damage may have taken its toll on the walls. Spider cracking is very common among plaster walls and is caused by the expansion and contraction of the surface coat (white coat) plaster. It can be recognized as very thin veins just below the surface of the paint. These cracks are normally thinner than a strain of hair and may form a network of cracks covering the entire wall.
Spackling the plaster walls with a very thin coat of joint compound may hide these imperfections. If the wall surface has extensive spider cracks, covering the wall surface with a wall liner such as Flexwall, Glidwall, or Durawall, will cover and seal the wall and create a new smooth surface for painting. These wall coverings are sold through commercial paint supply firms and are installed like wallpaper.
By Stephen Ferrandi, Director, KLNB Regious Properties
Stephen Ferrandi is the Director of KLNB Religious Properties, a real estate firm serving religioius clients in Maryland, D.C., Pennsylvania, and Virginia. He is one of the top experts in land development in the region. Mr. Ferrandi frequently contributes real estate related articles to both print and online publications.