Blok-Guard & Graffiti Control VOC 15

Blok-Guard & Graffiti Control VOC 15 — Clear Masonry Waterproofer & Graffiti Repellent

Blok-Guard & Graffiti Control VOC 15 (formerly Blok-Guard & Graffiti Control Ultra 15) is a high-performance, clear, solvent-based silicone elastomer engineered to weatherproof concrete block and other porous masonry surfaces. Formulated for contractors working on exterior walls, it penetrates and fills pores to prevent water infiltration through surfaces exposed to normal weathering conditions. The product simultaneously delivers graffiti resistance, making treated surfaces easier to clean after vandalism with little to no change to the masonry's natural appearance.

Unlike film-forming surface sealers, Blok-Guard & Graffiti Control VOC 15 penetrates deeply into porous substrates, allowing the masonry to continue breathing while blocking water and graffiti at the pore level. With a VOC content of less than 100 g/L, it is compliant with all national, state, and district AIM VOC regulations, making it a viable specification choice across jurisdictions where other solvent-based products may be restricted.

Key Features & Benefits

Dual-Function Water & Graffiti Protection

Treated surfaces resist penetration from most types of graffiti while simultaneously blocking rainwater infiltration through exterior block walls. This dual protection reduces long-term maintenance costs and keeps surfaces cleaner longer between service intervals.

Effective on Hard-to-Seal Porous Surfaces

The silicone elastomer formulation penetrates and fills pores in difficult-to-seal substrates like concrete block, unglazed terra cotta, and porous tile — surfaces where many conventional sealers underperform. This makes it a practical solution for masonry types that require deep penetration rather than surface coating.

Crack-Bridging Water Resistance

Blok-Guard & Graffiti Control VOC 15 resists water penetration when applied over existing shrinkage cracks of 0.02 inches or less. For contractors dealing with minor surface cracking common in cured concrete and block, this provides an added margin of protection without requiring full crack repair prior to application.

Moisture and Stain Control

The treatment helps control efflorescence, mildew, and other moisture-related staining that commonly develop on exterior masonry. By limiting water ingress at the surface, it addresses the root cause of many recurring cosmetic and structural maintenance issues.

Breathable Formula — Does Not Trap Moisture

Treated surfaces retain vapor permeability, allowing moisture vapor to escape from within the wall assembly. This prevents the moisture entrapment and spalling issues that can occur with non-breathable film-forming sealers applied to masonry.

Excellent UV Stability and Temperature Resistance

Treated surfaces withstand extreme temperatures and exhibit excellent UV stability, maintaining performance on exposed exterior facades subject to direct sunlight and thermal cycling. Surface beading is also excellent, confirming ongoing water repellency after application.

Simplified Graffiti Removal

When graffiti does occur, removal is fast and easy using PROSOCO's Graffiti Remover product. The treated surface prevents graffiti from bonding as aggressively to the substrate, reducing the labor required for remediation.

Broad VOC Regulatory Compliance

With a VOC content below 100 g/L, the product is compliant with all national, state, and district AIM VOC regulations. Contractors and specifiers working in heavily regulated jurisdictions can use this product with confidence across diverse project locations.

Common Applications

Exterior Concrete Block Walls

Blok-Guard & Graffiti Control VOC 15 is specifically engineered to control rainwater penetration through exterior concrete block walls, making it ideal for commercial, institutional, and industrial masonry construction.

Brick Facades

Applies to brick surfaces to repel water and resist graffiti adhesion, particularly on publicly accessible building facades where vandalism risk is elevated.

Unglazed Terra Cotta

Effectively seals unglazed terra cotta, a highly porous material that is difficult to protect with standard sealers, without altering the substrate's natural appearance.

Porous Tile

Suitable for porous tile surfaces on exterior applications where water infiltration and staining are ongoing concerns.

Concrete Surfaces

Protects poured and precast concrete from water penetration and graffiti, including surfaces with minor shrinkage cracking up to 0.02 inches.

Select Natural Stone

Compatible with some natural stones — testing is always required to confirm desired results and avoid color enhancement or darkening on sensitive substrates.

Compatible Materials

• Concrete block
• Brick
• Unglazed terra cotta
• Porous tile
• Concrete (poured and precast)
• Some natural stones (test prior to full application)

Product Documents

• Product Data Sheet
• Product Data Sheet (Canadian French)
• Safety Data Sheet
• Safety Data Sheet (Spanish)
• SDS Canadian French
• VOC Compliance
• LEED Verification Letter

Application Instructions

Limitations — Review Before Application

• May darken or enhance the natural color of some surfaces. Always test to ensure desired results.
• Not suitable for extremely dense or polished surfaces.
• Not suitable for asphaltic or painted surfaces.
• Not recommended for below-grade applications.
• Will not prevent water penetration through structural cracks, defects, or open joints.
• May damage glass or be difficult to remove — always protect glass prior to application.
• Not recommended for horizontal surfaces, including horizontal wood surfaces.

Surface Preparation

1. Ensure the surface is clean, dry, and absorbent. If cleaning is necessary, use the appropriate PROSOCO cleaner. Do not use raw acids.
2. Allow cleaned surfaces to dry completely before application.
3. Newly constructed or repointed surfaces must cure for 28 days before application.
4. Ensure all sealant and caulking compounds are in place and fully cured before application.
5. Fill cracks and voids to prevent penetration of fumes into the building.
6. Cap and make watertight the top of walls prior to application.
7. Protect people, vehicles, property, plants, windows, painted surfaces, anodized aluminum, metal, and glass from contact with product.

Temperature Requirements

1. Surface and air temperatures must be between 40–90°F (4–32°C) during application.
2. Higher temperatures evaporate the solvent carrier and reduce penetration — avoid application in extreme heat.
3. If freezing conditions existed prior to application, allow masonry to thaw completely before proceeding.

Equipment

1. Recommended application method is high-volume, low-pressure spray (less than 50 psi). Fit spray equipment with stainless steel or brass fittings and gaskets suitable for solvent solutions. Use fan spray tips to avoid atomization.
2. For small-scale application or when spray is not appropriate, apply using a brush or roller. Use nylon or other synthetic materials resistant to solvent solutions.

Storage and Handling

1. Store in a cool, dry place away from potential ignition sources. Keep tightly closed when not in use.
2. Maintain storage temperature between 45–100°F (7–38°C).
3. Do not double-stack pallets.
4. Dispose of unused product and container in accordance with local, state, and federal regulations.
5. Published shelf life of 1 year assumes upright storage of factory-sealed containers in a dry place.

Technical Specifications

Safety Data Summary

Hazard Information

• Flash point of 100°F (38°C) — flammable liquid; keep away from ignition sources
• Contains petroleum-based solvent — use in well-ventilated areas
• May damage glass and be difficult to remove from certain surfaces
• 24-Hour Emergency Information: INFOTRAC at 800-535-5053

Personal Protective Equipment

• Always read the full label and Safety Data Sheet (SDS) before use
• Use appropriate safety equipment as identified in the SDS during application and handling

Safe Handling

• Store in a cool, dry place away from potential ignition sources
• Keep container tightly closed when not dispensing
• Do not double-stack pallets during storage
• Dispose of unused product and container in accordance with local, state, and federal regulations
• Apply appropriate job site controls during application to limit exposure

Frequently Asked Questions

Q: What is the difference between Blok-Guard & Graffiti Control VOC 15 and the former Blok-Guard & Graffiti Control Ultra 15?
A: Blok-Guard & Graffiti Control VOC 15 is the renamed version of Blok-Guard & Graffiti Control Ultra 15. The product formulation is a high-performance solvent-based silicone elastomer — the name change reflects updated branding; always verify with the current Product Data Sheet.

Q: Can this product be used on below-grade masonry?
A: No. Blok-Guard & Graffiti Control VOC 15 is not recommended for below-grade applications.

Q: Will it seal structural cracks or open joints?
A: No. The product resists water penetration over existing shrinkage cracks of 0.02 inches or less, but will not prevent water penetration through structural cracks, defects, or open joints. These conditions must be addressed before application.

Q: Will it change the appearance of my masonry?
A: The product is designed to provide little to no change to the natural appearance, but it may darken or enhance the color of some surfaces. Always test on a representative area to ensure desired results before full application.

Q: What is the recommended application method?
A: The recommended method is high-volume, low-pressure spray (less than 50 psi) using stainless steel or brass fittings with fan spray tips. Brush or roller application is acceptable for small-scale work or where spray application is not appropriate.

Q: How soon after new construction can the product be applied?
A: Newly constructed and repointed surfaces must cure for 28 days before application of Blok-Guard & Graffiti Control VOC 15.