Technical Info

Concrete Materials

Portland Cement: type 1 Portland Cement Gray or Lehigh White
Course/Fine Aggregate - Sand and Gravel: hard, durable, selected and graded; free of material that causes staining or reacting with cement.
Pigments: Non-fading, resistant to lime and other alkalis
Water: Drinkable, free from foreign materials in amounts harmful to concrete.
Compressive Strength: 5000 PSI minimum at 28 days

General: fabricate precast concrete units complying with manufacturing and testing procedures, quality control recommendations, and following dimensional tolerances, unless otherwise indicated.
Molds: Accurately construct molds mortar-tight and of sufficient strength to withstand pressures due to concrete placing operations and temperature changes. Maintain mold work to provide completed pre-cast concrete units of shapes, lines and dimensions indicated, within specified fabrication tolerances.
Dimensional Tolerances of Finished Units: Ornamental architectural precast concrete, being tapered by design, is measured for length, width and thickness at the surface from which the mold is loaded maintaining plus or minus 1/16 of an inch tolerance. Overall height and width measured at face adjacent to mold at time of casting
Surface Finish: Fabricate precast units and provide exposed surface finished as follows:
- Standard- Randomly spaced/sized voids inherent in the texture.
- Poured - less voids than traditional but not typically void free
- Acid-Washing- Light abrasive blast applied to the cast finish
- Natural/Stone - High irregular, rusticated finish.

Corrugated Wall Ties - Included in moldings as the mechanical fastener. 22 gauge mill galvanized steel.
Thinset
Premium grade construction adhesives which come in tubes should be used for bonding columns and on flat surfaces.

These are non-structural, self supported units.
Quality Assurance - Fabricator has sufficient production capacity to produce, transport and deliver required units without causing delay in the work.
Design modifications will be made only as necessary to meet field conditions and to ensure proper fitting of the work and only as acceptable to Architect. Maintain general design concept shown without increasing or decreasing sizes of members or altering profiles and alignment shown without architect's approval. Modifications may need to be considered in view of budget constraints.
Color and texture: To match Architect's sample, when viewed with unaided eye in good typical lighting at distance of 10 feet; no obvious repairs or chips when viewed at distance of 20 feet.
Install: Wet stone thoroughly just prior to setting by drenching with clean water.
Examination (Install/Technical) - A. Do not begin installation until substrates have been properly constructed verify that substrates are plumb and true. B. If substrate preparation is the responsibility of another installer, not Architect of unsatisfactory preparation before proceeding. C. check field dimensions before beginning installation. If Dimensions vary too much from design dimensions for proper installation, notify Architect and wait for instructions before beginning installation.