Date: November 26, 2007
Byline: Don Mitchell
Black Horse Inn Stucco to be Green
FOR IMMEDIATE RELEASE CONTACT
Don Mitchell, 215-651-4280
Flourtown, PA — Despite decisions to keep a revitalized Black Horse Inn consistent with 17th century color schemes, it turns out the new stucco covering the entire building will be green no matter what. Environmentally green that is, because of the materials being used.
"Portland cement is probably the largest green house gas producer in the world," says Andy deGruchy of deGruchy Masonry Restoration, referring to the typical cement-based mortar used in a majority of construction since the mid1900s. "We're supplying a lime-based mortar for the Black Horse Inn project, which is produced without creating a lot of green house gas. In fact, by using lime-based mortar on the Inn alone, we're sparing the environment about 520 lbs. of CO2."
But the decision to use a lime-based mortar for the inn's stucco exterior didn't just come down to being green. Chris Frey of Keystone Preservation Group recommended the natural hydraulic lime-based stucco for the project "in part because it is consistent with the period of 1880 we're restoring to. But it also won't react adversely with the original materials used on the building," says Frey. "The lime-based mortar breathes, has strength and durability, and over time is much more flexible as the building adjusts and settles. Cement-based stuccoes tend to be harder, less flexible and less breathable than hydraulic limes, characteristics that could cause a whole myriad of problems down the road. Like cement, natural hydraulic lime cures relatively quickly, but it is also more durable than traditional lime, which we deem desirable for both installation and long-term maintenance."
The tradition of burning lime to produce mortar dates back centuries and is widespread. Evidence of the practice is still visible today in Montgomery County. Driving along Germantown or Butler Pikes you might notice the old limekilns preserved there. The community of Oreland, right here in Springfield Township, was also home to several limekilns due to a rich layer of lime beneath our feet.
Prior to the early 1900s masons would simply take burned lime and add sand and water to create a mortar mix. But around 1870, cement was introduced in the US and over the next 60 years it became the favored material for most mortar applications. It had the advantage of setting faster, however, over time it has proven to be far more detrimental to the environment by way of its production.
During this latest facelift for the Black Horse Inn, the original stucco recently revealed a secret about the building's construction. It had been thought for some time that the South end of the building, which housed the bar on the right as you face the inn, was older than the larger North end. But that thinking changed dramatically last month when the workers from Daley Plastering in Bridgeport began to remove the old stucco from the front of the building.
With the underlying stone surface exposed, one could plainly see a layer of stucco sitting 'sandwiched' between the South and North portions. The existence of that sandwiched layer confirmed that one of the two sections had, at one time, had an exterior wall that required the stucco's protection. But what surprised everyone was that the sandwiched layer was adhering to the North end of the building, not the South end. In other words, the North section predates the tavern portion.
With the stucco restoration well under way, the current phase of work on the inn includes structural stabilization and waterproofing in the basement, all masonry repair, rehabilitation of windows and entryways, and the restoration of the wrap-around porch on the front and South sides of the building.