Opera House Exterior Preservation Project

1. The stone water table courses on the west side of the building to be capped with mortar based parge coat: a. Stone to be cleaned and any loose mortar removed before binning work. b. An 18” deep trench to be dug to expose wall below grade. Parge coat to extend at least 6” below grade. c. A two-coat parge system to be installed using Sakrete Surface Bonding Cement (gray in color), or an equal product. Existing stone and mortar to be wetted per manufactures recommendations prior to installation. d. Install sloped galvanized metal flashing drip edge, inset in mortar joint and caulk in place. e. Fill drain trench with gravel and slope final grade away from wall at min. 2% slope. 2. Repair mortar joints on building: 1. Use appropriate lime-based mortars. Mortar to match as closely as possible existing color, texture, aggregate, and profile. Procedure as recommended: a. Remove damaged or inappropriate mortars using hand tools only. Do not use any power tools. Old mortar to be removed a min. depth of 2 to 2 ½ times the width of the joint to ensure an adequate bond and to prevent mortar “popouts.” b. Use Type N mortar (Portland Cement-based mortar not to be used). Type N mortar mixing suggested to be: Lime-based mortar used for repainting, lime to conform to ASTM C 201, Type S, or Type SA, Hydrated Lime for Masonry Purposes. A trial-and-error process may be necessary to find the right mix. Fill Deepest joints first by compacting the mortar in several layers, in ¼” increments, allowing for thumb print hardness before applying the next payer. The mortar should be slightly recessed from the face of the stone and should not extend over the edge of the stone. c. New mortar/sand to match the historic mortar in color, texture and tooling. d. The new mortar must have greater vapor permeability and be softer (measured in compressive strength) that the existing masonry stone. e. The new mortar to be as vapor permeable and as soft or softer (measured in compressive strength) than the historic mortar. 3. Remove and Replace existing concrete as necessary. Seal joints with one part Polyurethane Elastomeric Sealant (SIKAFLEX 1A or Equivalent) 4. Other related work as necessary.

Division 09 -

Finishes.