Rainguard Pro Micro-Seal Silane/Siloxane Water Repellent Review (2026)
By Nate Sawyer, Editor · Updated July 2026
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- Brick and block walls
- Stucco and CMU
- Vertical masonry water repellency
- Clear natural finish
A breathable silane/siloxane repellent built for vertical brick, block, and stucco that keeps wind-driven rain out while letting the wall breathe. Pick it for above-grade masonry walls where you want an invisible, breathable repellent rather than a waterproof coating.
Pros
- Penetrating silane/siloxane repels wind-driven rain on vertical brick, block, and stucco without a film
- Breathable and vapor-permeable, so trapped moisture can still escape the wall
- Zero-VOC, low odor, and non-yellowing with a long material warranty
Cons
- Coverage swings dramatically with masonry porosity, making product estimating tricky
- Water-repellent only, not a waterproofer, so it will not stop liquid water under head pressure
- No color enhancement or gloss, so it does nothing decorative for the wall
Specifications
| type | Penetrating silane/siloxane water repellent |
|---|---|
| finish | Clear, natural, non-film-forming |
| coverage | Approx 40-400 sq ft per gallon (varies widely by porosity) |
| windDrivenRain | Tested to resist 98 mph wind-driven rain |
| warranty | Up to 10 years |
| voc | Zero VOC, low odor |
| breathable | Vapor-permeable |
Frequently Asked Questions
- Is a water repellent the same as a waterproofer?
- No, and the distinction matters. Micro-Seal repels wind-driven rain on vertical masonry but will not stop liquid water under head pressure. For a below-grade wall with water pushing through, this is the wrong product category.
- Will it trap moisture in the wall?
- No — it is breathable and vapor-permeable, so moisture inside the masonry can still escape. That is essential on brick and stucco, where a vapor-tight coating causes spalling.
- How much Micro-Seal will a wall take?
- Hard to estimate — coverage swings from roughly 40 to 400 sq ft per gallon depending on masonry porosity. Test a small area first rather than buying for the whole wall on a guess. It is tested to resist 98 mph wind-driven rain with up to a 10-year warranty.