Native Custom Stone:

As requested, Testing, Engineering & Consulting Services (TEC Service) is proud to present this report containing results for the testing of stone veneers in accordance with ICC Evaluation Services AC51: Acceptance Criteria for Precast Stone Veneers. AC51 includes the following tests:

• Compressive Strength – ASTM C192 and ASTM C39
• Tensile Strength – ASTM C 190
• Flexural Strength – ASTM C 348
• Shear Bond Strength – ASTM C 482
• Moisture Absorption – AC51 Section 4.6
• Freeze-Thaw Resistance – ASTM C67
• Equilibrium Density – ASTM C567

Saturated Weight – AC51 Section 4.1.
Compressive strength of the mortar was determined on five, 4 x 8 inch cylinders at 28 days in accordance with ASTM C39. The average compressive strength of the five specimens must be a minimum of 1800 psi and no sample may vary from the average by more than 10%. Results are listed in Table 1.

Table 1: 28 Day Compressive Strengths

28 Day Average
5,897

Flexural strength of the mortar was determined on five, 2 x 2 x 8 inch beams at 28 days in accordance with ASTM C348. The flexural strength of an individual sample may not vary from the average by more than 10%. Results are listed in Table 2.

Table 2: 28 Day Flexural Strengths

28 Day Average
933

Tensile strength of the mortar was determined on five briquettes at 28 days in accordance with ASTM C190. The tensile strength of an individual sample may not vary from the average by more than 10%. Results are listed in Table 3.

Table 3: 28 Day Tensile Mortar Strengths

28 Day Average
320

Shear bond strength was determined in accordance with ASTM C 482. Five samples were prepared for cement board and CMU backings. The shearing strength must be a minimum of 50 psi and the individual bond strength results shall not vary from the average by more than 20%. Results are listed in Table 4.

Table 4: Shear Bond Strength

Equilibrium density was determined in accordance with ASTM C 567, by measurement of 5 samples. The absorption, based on the dry weight, was measured on 10 samples in accordance with section 4.6 of AC51. The water absorption requirements in Table 2 state that the maximum percent water absorption for veneers weighing more than 85 lb/ft3 and less than 105 lb/ft3 is 18%.

The saturated weight is the equilibrium density, increased by the absorption, and multiplied by the volume of veneer per unit area of wall. The volume of each veneer unit was determined by measuring the water displaced by a saturated veneer unit. Wall surface area was determined by measurement. The maximum value of the saturated weight per square foot is 15 lbs/ft2. The average result is shown in Table 5.

Table 5 – Average Equilibrium Density, Absorption and Saturated Weight

Freeze-thaw resistance was determined in accordance with ASTM C 67. Five veneer specimens for each veneer type were subjected to 50 freeze-thaw cycles. The percent weight loss is determined as the percentage of the original dry weight of the specimen. The specimens are considered failing if they break, disintegrate or loose more than 3% of their mass. The average weight loss is for each veneer type is reported in Table 6.

Table 6 – Results of Freeze-Thaw Testing

Report of AC51 Testing for Stone Veneers
March 5, 2009
TEC Services Project Number: TEC 08-0678
TEC Services Laboratory Number: 08-347
Based on the results to date, Native Custom Stone Veneer Samples comply with AC51.