Left side is the repair; right side is the original
Sifting sand
As you know, The Speaker’s House has collaborated with the Heritage Conservation Network to create a hands-on workshop at which four apprentices would train in the art of repairing masonry with lime-based mortar.
Before any work can be done on the building, there is much background prep work. Yesterday the apprentices spent the day making up different samples of mortar and samples of a stone patch that will be used to make small repairs on the brownstones. It takes an artist’s eye to do this kind of work – to match the color and consistency of the original stone and original mortar.
Andy purchased some sand from a local source, which will be used as the basis for the mortar.
After much testing, the decision was to mix two cups of sand, with one cup of lime, one cup of stone and a handful of lime “inclusions.” The masonry apprentices have spent hours sifting sand. The object was to separate the natural stone content in the sand so they can control how much stone is in the final mortar mix. And what about those lime inclusions? These are little balls of lime that form naturally during the slaking process. Because the original mortar had lime inclusions, the masons are trying to replicate that look by adding lime inclusions.
Yesterday they also tested the mortar on the building – in this photo, it is hard to tell the original mortar from the repair.
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