Limestone Cladding Restoration
The Department of Veterans’ Affairs building, located in Washington, DC, is a limestone clad structure built in 1916. We were engaged to perform an exterior assessment of the ground and second floor levels of the masonry façade. Conditions were noted including atmospheric and biological soiling, gypsum crusts, metallic stains, stone losses, failed and inappropriate patches/previous repairs. A major source of concern was deterioration at the Metro entrance, which substantially changed the corner of “I” and 17th Sts NW in the 1970’s. Investigation revealed severely corroded steel at this site due to poor detailing.
Based on the findings identified in the assessment and the engineer’s recommendations, we then performed conservation treatment of the identified exterior facades. We coordinated with the client to minimize impact on the building and its occupants by working off-hours where feasible. The treatment included removal and replacement of failed cladding, structural steel repairs, overall detergent and hot water cleaning; micro-abrasion of tenacious gypsum crusts; spot treatment of specific metallic stains; and patching of voids and losses using a custom color-matched repair mortar.