The work of this general contract included the removal of all marble paving and veneer, selective replacement of marble, structural stabilization and waterproofing of the substrate, and full rebuilding of the Marble Terrace and all Marble Stairs at the perimeter of the State House. The work included the restoration of both Tennessee and Georgia Marble in both phases. Specialty Stone cleaning required extensive mock ups to find a combination of products that would lift the metal oxidation of existing anchorage and copper flashing set into the existing marble. The cupric and ferrous staining required a combination of chemical and water based poultices and Sure-Klean products from Prosoco.
|Contract Value: $9,000,000
Stone removal, salvage, and installation.
Installation of new stone wall panels, balustrades, pavers, and stairs.
Stone cleaning and repointing of existing Stone.
The Stone Removal, Salvage, Selective Replacement, and Resetting was the most complex portion of the work. The brick masonry back up walls and piers supporting the terrace, stairs and side walls were failing, leading to extensive damage of the marble veneer and paving. All veneer and paving face stone had to be removed, with a majority to be salvaged, to allow full access to the back up for full brick wall rebuilding, steel augmentation, and waterproofing of the terrace. This included the removal of over 4,100 marble pavers, 270 solid marble stair treads, 670 pieces of balustrade piers, caps, and base, and 535 balusters of which approximately 75% of the pieces had to be salvaged for reinstallation in the same position they were originally. The monumental stair at the front of the building required its entire foundation to be rebuilt with precast sub-treads to support the new and salvaged treads. Although a thorough investigation and survey had been completed by Durkee & Brown prior to the contract being executed, NER Construction was directed by the specification to completely examine and confirm the amount of deterioration of each individual stone before they were moved and temporarily stored. All stone was identified, labeled, and catalogued for use during the re-installation.
The Stone Repointing was another process which required that a mock up be performed by each mechanic performing the work. All existing marble stone to stone joints at the terrace veneer were between 1/8" and 3/16" wide. Saws could only be used if approved by the designer and the owner. Hand held Metabo grinders with 4" diamond blades were utilized to cut all bed joints and head joints, with the detailed work being cut using a Metabo Die grinder with an undersized bit. All cuts with saws were made as a single cut through the midline of the joint as reviewed and approved by the designer and the owner. A majority of the cutting work for the repointing was successfully completed with some form of rotary saw or grinder. The pointing of the prepared stone joints were done in a manner very similar to the requirements at the Massachusetts State House. Any joints that were cut deeper than the 1/2" depth were back pointed and moisture cured prior to the final pointing. The typical pointing was completed in two separate lifts with mist dampening of the joints prior to the application of the mortar. The type N mortar was only installed within two hours of mixing, with the second lift installed once the first lift was partially cured.
Rhode Island State House - Entrance Plaza Reconstruction
NER Construction continued the Restoration work of the Rhode Island State House with the reconstruction of the grand entrance plaza to this Providence, Rhode Island Landmark. The existing Georgia marble slabs, Tennessee marble pavers, and brick pavers were set on a sand setting bed that had settled and warped over time causing many of the original marble pavers to crack or break. The scope of this project was to selectively demolish and salvage selected stone pavers and reset them alongside replacement stone on a compacted gravel and concrete base. The rebuilt grand entry now complements the cleaned and restored Terraces that NER completed over the last two phases.