Formstone

Formstone is a type of stucco[1] commonly applied to brick rowhouses in many East Coast urban areas in the United States, although it is most strongly associated with Baltimore.

It was not long until rowhouse homeowners in more urban and working-class areas of Baltimore wanted the clean and polished look of Formstone.

The company opened successful franchise locations in various cities across the United States but Baltimore was the epicenter of the Formstone phenomenon.

[10] Aluminum and vinyl siding, much cheaper ways to weather-proof buildings, became more popular and contributed to the decline of Formstone and other simulated stone products.

Formstone, described as "[a]n odd architectural fad" by urban design critic John King, appeared in San Francisco in the 1930s and '40s.

[6] Formstone is applied in three layers, anchored by a perforated metal lath attached to the underlying brick with nails.

[6][3] One major failure of Formstone is that the metal lath holding the faux stone to the building can start to pull away from the brick.

Applying Formstone to rowhouses constructed with early brick from the eighteenth and nineteenth centuries caused many problems.

Features such as cornices, belt courses, lintels, and sills were not only decorative, they were necessary for diverting water away from the building, leading to even more damage from moisture intrusion.

[16] When a building owner decides to remove the Formstone, historical fabric and significant features can be damaged during this process.

When the metal lath is removed, it leaves the original poor quality brick surface pock-marked with holes in the mortar joints.