Replacement of the exterior stone cladding required use of several mast-climbing work platforms. The large span between masts and the quantity of stone being replaced, transmitted significant loads into the existing, aged concrete structure. The structure is located on the National Mall, a short walk from the US Capitol, so the renovation effort needed to move forward flawlessly.

The structure consisted of a central building built on a block, with an underground parking structure that extended to the curbs. The scaffolding masts would rest on bases set on the parking garage roof. Repairs had been made to the roof to stop water leakage from the sidewalk level.

Our effort involved review of the existing drawings, location of the contractor's masts on the existing concrete structure, and evaluating the loading of the concrete structure for possible damage.