Table 1 - Design Criteria:
| Corrosion Risk Category | Chloride Content*** | Minimum Current Density at 20 Years |
| Low to Moderate | <0.8% | 0.4mA/m2 |
| High | 0.8 to 1.5% | 0.8mA/m2 |
| Extremely High | >1.5% | 1.6mA/m2 |
*** Chloride content is calculated as a percentage by weight of cement.
Anode Spacing
The following anode spacing guidelines are based on achieving the minimum current density for the appropriate corrosion risk category 20 years after installation.
NOTE: In warmer or more demanding conditions (such as marine environments), Sika Galvashield XPX anodes are recommended to achieve the 20 year anode life.
Table 2 - Maximum Anode Spacing for New Construction and Carbonated Concrete:
| Steel Density Ratio* | Sika Galvashield XPT / Sika Galvashield XP Compact** | Sika Galvashield XP2 | Sika Galvashield XP4 / XPX |
| <0.3 | 700 mm | 700 mm | 700 mm |
| 0.31 to 0.60 | 700 mm | 700 mm | 700 mm |
| 0.61 to 0.90 | 580 mm | 700 mm | 700 mm |
| 0.91 to 1.20 | 500 mm | 700 mm | 700 mm |
| 1.21 to 1.50 | 440 mm | 680 mm | 700 mm |
| 1.51 to 1.80 | 400 mm | 600 mm | 700 mm |
| 1.81 to 2.10 | 370 mm | 560 mm | 700 mm |
* Steel surface area / concrete surface area.
** Sika Galvashield XP Compact may have reduced life due to reduced zinc mass (40g).
Table 3 - Maximum Anode Spacing for Low to Moderate Corrosion Risk (Chloride Content <0.8%***):
| Steel Density Ratio* | Sika Galvashield XPT / Sika Galvashield XP Compact** | Sika Galvashield XP2 | Sika Galvashield XP4 / XPX |
| <0.3 | 675 mm | 700 mm | 700 mm |
| 0.31 to 0.60 | 450 mm | 700 mm | 700 mm |
| 0.61 to 0.90 | 350 mm | 575 mm | 700 mm |
| 0.91 to 1.20 | 300 mm | 475 mm | 625 mm |
| 1.21 to 1.50 | 275 mm | 425 mm | 550 mm |
| 1.51 to 1.80 | 250 mm | 375 mm | 500 mm |
| 1.81 to 2.10 | 225 mm | 350 mm | 475 mm |
* Steel surface area / concrete surface area.
** Sika Galvashield XP Compact may have reduced life due to reduced zinc mass (40g).
*** Chloride content is calculated as a percentage by weight of cement.
Table 4 - Maximum Anode Spacing for High Corrosion Risk (Chloride Content 0.8% to 1.5%***):
| Steel Density Ratio* | Sika Galvashield XPT / Sika Galvashield XP Compact** | Sika Galvashield XP2 | Sika Galvashield XP4 / XPX |
| <0.3 | 450 mm | 700 mm | 700 mm |
| 0.31 to 0.60 | 300 mm | 475 mm | 625 mm |
| 0.61 to 0.90 | 250 mm | 375 mm | 500 mm |
| 0.91 to 1.20 | 200 mm | 325 mm | 425 mm |
| 1.21 to 1.50 | 175 mm | 275 mm | 375 mm |
| 1.51 to 1.80 | 150 mm | 250 mm | 350 mm |
| 1.81 to 2.10 | 125 mm | 225 mm | 325 mm |
* Steel surface area / concrete surface area.
** Sika Galvashield XP Compact may have reduced life due to reduced zinc mass (40g).
*** Chloride content is calculated as a percentage by weight of cement.
Table 5 - Maximum Anode Spacing for Extremely High Corrosion Risk (Chloride Content >1.5%***):
| Steel Density Ratio* | Sika Galvashield XPT / Sika Galvashield XP Compact** | Sika Galvashield XP2 | Sika Galvashield XP4 / XPX |
| <0.3 | 300 mm | 475 mm | 625 mm |
| 0.31 to 0.60 | 200 mm | 325 mm | 425 mm |
| 0.61 to 0.90 | 175 mm | 250 mm | 350 mm |
| 0.91 to 1.20 | 150 mm | 225 mm | 275 mm |
| 1.21 to 1.50 | 125 mm | 175 mm | 250 mm |
| 1.51 to 1.80 | 100 mm | 150 mm | 225 mm |
| 1.81 to 2.10 | N/A | 125 mm | 200 mm |
* Steel surface area / concrete surface area.
** Sika Galvashield XP Compact may have reduced life due to reduced zinc mass (40g).
*** Chloride content is calculated as a percentage by weight of cement.
NOTE: Spacing should be reduced for continuously wet substrates to extend the expected service life of the anode. Where stirrups in beams or columns are exposed, place a Sika Galvashield XPT / XP2 / XP4 / XPX anode at each stirrup location. Spacings are based on an average annual temperature of 10°C.
