Scope:
Sound absorptive concrete masonry units shall be used to construct exterior walls or partitions as shown on the plans and/or indicated in the Schedule of Finishes.

Material:
All sound absorptive masonry units shall be SOUNDBLOX made on standard block machines using molds furnished or approved by The Proudfoot Company, Inc., Monroe, Connecticut. They shall be made of carefully prepared aggregate and shall meet the current ASTM C-90 or ASTM C-129 requirements as appropriate. Carefully controlled use of the SOUNDBLOX molds shall be employed so all units have one end of the cavities tightly closed. Slots and edges shall be straight and clean. Where Types Q, RSC, RSC/RF or RSR SOUNDBLOX units are called for, filler elements as supplied by The Proudfoot Company Inc., shall be installed in the cavities of the blocks at the block plant. The fillers shall be of specially fabricated incombustible fibrous material, cut accurately to size and installed as recommended. The fillers shall have metal septa laminated to one side of the fibrous material and shall be installed with the septa facing away from the slots. Where 8" Type Q units are called for, they shall have a bare (without fibrous material) metal septum as furnished by The Proudfoot Company, Inc., installed in each cavity in the recommended manner at the block plant.

Sizes and Types:
SOUNDBLOX units shall be 8" x 16" nominal face size. They shall be of the thickness (4", 6", 8" 10" or 12") and Type (A-1, RSR, RSC, RSC/RF or Q) as shown on the plans and/or indicated in the Schedule of Finishes.

Installation:
SOUNDBLOX units shall be installed by the General Contractor (or Masonry Contractor) using only mechanics skilled in the laying of masonry blocks. All necessary cutting on the job site shall be performed with power tools in such a manner as to provide straight and true edges. No chipped or broken blocks shall be used. SOUNDBLOX units shall be laid in running bond (or stack bond) with the open ends of the cavities facing downward. The slots shall be exposed to the area where the sound absorption is desired as indicated on the plans. Care shall be taken to ensure that the slots are kept free of mortar or debris above the mortar joints. Lines shall be straight and true and the SOUNDBLOX workmanship shall otherwise conform to all requirements of the General Specifications for masonry work.

Painting:
SOUNDBLOX units may be painted without significant reduction of sound absorption from the values shown which were determined after the faces has already been painted. Lightweight SOUNDBLOX units have substantially more sound absorption when unpainted but - except for split-rib units - few units are ever left unpainted. Walls of SOUNDBLOX units made of lightweight, porous aggregates must be heavily painted with cement base or other sealing type paint on the unslotted side to prevent porous sound transmission where maximum sound transmission loss is desired. Such painting is also required on ordinary hollow concrete masonry units of lightweight, porous aggregates to prevent porous sound transmission.

General Description
SOUNDBLOX Type RSC
SOUNDBLOX Type RSC/RF
Sound Transmission Loss