Protect brick surfaces from rain, moisture, and freeze-thaw damage with penetrating, breathable water repellents. The following selections are formulated to penetrate deep, preserve appearance, and maintain masonry durability on chimneys, walls, and walkways. The list below highlights five top options from trusted brands, each offering siloxane or silane/siloxane chemistry designed to form invisible barriers without film formation.
| Product | Brand | Finish / Size | Key Benefit |
|---|---|---|---|
| ChimneyRx 300119 Masonry Chimney Water Repellent | CHIMNEYRX | 1 Gallon; Siloxane-based; Transparent | Deep penetration for breathable protection on brick & chimneys |
| Rainguard Water Sealers Brick Sealer (1 gal) | Rain Guard Water Sealers | 1 Gallon; Silane/Siloxane; Natural finish | Invisible, filmless waterproofer with no gloss |
| ChimneyRx Advanced Water Repellent (1 gal) | CHIMNEYRX | 1 Gallon; Polysiloxane | Breathable, long-lasting protection for masonry |
| Stormdry Brick Sealer (1 Quart) | Stormdry | 1 Quart; Cream-based, breathable | Deep penetration with 25-year protection |
| Siloxa-Tek 8500 Ready to Use (1 Gallon) | Ghostshield | 1 Gallon; Water-based silane/siloxane | Breathable, non-film forming, DOT-approved |
If you’re choosing a brick water repellent, consider how deeply you need penetration, whether you prefer a natural finish, and how important breathability is for your climate. The products below illustrate a range of approaches from film-free, breathable barriers to highly durable, deep-penetrating sealers.
ChimneyRx 300119 Masonry Water Repellent
The ChimneyRx 300119 Masonry Chimney Water Repellent uses an advanced siloxane formula that penetrates up to 1/4 inch into masonry and concrete. This breathable, non-film-forming coating protects brick chimneys while preserving the surface appearance. Its durable, long-lasting chemical bonds become part of the structure, offering protection against water intrusion without creating an unattractive film or gloss. Ideal for exterior chimneys, brick walls, and other vertical surfaces exposed to rain and freeze-thaw cycles.
Rainguard Brick Sealer — 1 Gallon
Rainguard’s Brick Sealer delivers penetrating protection with a filmless, hydrophobic barrier. It repels wind-driven rain and other contaminants while remaining invisible on unpainted brick. The sealer helps prevent damage from freeze-thaw cycles and moisture, supporting long-term durability without altering the natural appearance of brick floors, chimneys, and walls. This option is suitable for both indoor and outdoor applications where a natural finish is preferred.
Rainguard Brick Sealer (1 Gal) — Silane/Siloxane
This Rain Guard variant emphasizes a multi-purpose, no-gloss finish that does not change the brick’s appearance. The silane/siloxane blend penetrates unpainted surfaces to deter water intrusion, salt damage, and efflorescence. It is well-suited for chimneys, walkways, and garden walls where a natural look is maintained while ensuring long-term protection against weathering.
ChimneyRx Advanced Water Repellent — Clear Sealer
ChimneyRx Advanced Water Repellent provides a breathable polysiloxane-based seal that deeply permeates masonry, forming a flexible barrier. It is suitable for brick, stone, and concrete and can be applied over previously treated surfaces. The product works as a versatile waterproofer for both residential and commercial projects, including brick walls and chimneys. Its breathable nature helps prevent moisture buildup and related damage while maintaining surface aesthetics.
Rainguard Brick Sealer — 5 Gallons
The 5-gallon option from Rain Guard Water Sealers delivers the same invisible, filmless protection at a higher volume. It is ideal for larger projects or ongoing maintenance across multiple brick surfaces. The silane/siloxane formulation ensures deep penetration, water repellency, and a natural finish, preserving the brick’s original look while extending its service life against weather-related deterioration.
Stormdry Brick Sealer — 1 Quart
Stormdry Brick Sealer is a premium, cream-based formulation designed for deep penetration and long-term protection. It offers 25-year waterproofing for brick, stone, mortar, cement, sandstone, and granite, while remaining breathable to allow moisture to escape. This product is not recommended for limestone or painted surfaces, and it emphasizes durability and compatibility with traditional masonry substrates.
Siloxa-Tek 8500 Ready to Use — 1 Gallon
Ghostshield’s Siloxa-Tek 8500 is a water-based silane/siloxane penetrating sealer designed to reduce water and moisture intrusion on concrete, brick, masonry, and pavers. It is 100% breathable and non-film forming, preserving the natural look of the substrate. DOT-approved and resistant to chlorides and deicing salts, it mitigates cracking and spalling while providing long-lasting protection in exposed environments.
Buying Guide: Key Purchase Considerations
- Penetration depth: Deeper penetration typically yields longer-lasting protection, especially in saturated or high-moisture climates.
- Breathability: Choose breathable sealers if moisture buildup inside walls or chimneys is a concern; breathability helps prevent freeze-thaw damage.
- Finish and appearance: If you want a natural look with no gloss, opt for filmless or transparent formulas. Some products offer a very light sheen; test on a small area first.
- Surface compatibility: Confirm the sealer’s suitability for brick, mortar, stone, and concrete; some formulas are recommended only for certain substrates.
- Application and maintenance: Consider coat count, time to cure, and whether a water-based or solvent-based formula best fits your project and indoor/ outdoor use.
- Volume and project scale: For larger jobs, higher-volume options (gallons) may reduce cost and simplify application planning.
- Environmental and safety factors: Look for low-VOC options and DOT-approved formulations for outdoor use and transport considerations.
- Weather window: Plan applications for dry, moderate temperatures to ensure proper penetration and curing.