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  • Overview
  • Coverage Rate
  • Specs
  • ASTM Testing
  • Application

Micro-Seal SiH4 100% Silane Deep Penetrating Water Sealer | UV Resistant | Low VOC | Concrete Stucco EIFS CMU Block Clay Tile

Micro-Seal SiH4 100 is a 100% silane sealer designed to penetrate deeply into concrete and a variety of porous masonry substrates to prevent moisture intrusion, salt-ion intrusion, staining and freeze/thaw damage. This high solids 100% Silane water repellent provides protection from mold, mildew, and efflorescence.

Due to the small particle size, it penetrates deeper than Silane Siloxane blended and Siloxane formula water repellents for longer lasting protection and superior performance. The depth of penetration can be controlled based on application spread rates and how much is applied. Ideal for concrete and masonry substrates due to it’s reactive nature that chemically bonds with the substrate. Micro-Seal SiH4 100 is not affected by UV light and wind-driven rain.

What makes Micro-Seal SiH4 different? A proprietary ingredient called Micro-Lok™. This additive ensures a long lasting mechanical bond and creates a hydrophobic barrier not affected by weathering, salt, dirt, freezing temperatures, UV light and wind-driven rain. Micro-seal SiH4 is a penetrating silane sealer invisible after application as it penetrates completely below the surface.

Available in two size options, 1 gallon and 5 gallons, Micro-Seal SiH4 Silane is supplied Ready-to-Use.

Primer: For masonry surfaces, recommended Restore-N-Prep as pretreatment to properly clean the surface.

Topcoat: None Required.


  • Construction & Remodel Projects: Exterior Buildings | Retaining Walls, Warehouse | Factory | Parking Garage Floors, Bridge Abutments, Stadiums
  • Homeowner Projects: Exterior brick|stucco walls, chimneys, driveways, garage floors, decks, patios, porches, walkways, fences.
  • Non-Traditional Applications: Clay tile roofs, clay|concrete flower pots, indoors floor and bathroom tile mortar grout sealing


  • Small Particle Size for Deeper Penetration and longer lasting results
  • Will not yellow, haze, crack or peel
  • Overspray Does not etch metal or glass
  • No film formation – does not change looks of the surface
  • Allows substrates to breathe without trapping moisture
  • Reduces rebar rusting in concrete and surface erosion from salts
  • Can be subjected to wheeled or vehicular traffic immediately after application



The coverage depends on the surface. Test the product on a small area of the substrate to estimate coverage. Extremely porous surfaces may require multiple coats.

The use of fluted, scored block, raked joints, sandblasted or etched surfaces will result in greater absorption and lower coverage rates, by up to 40%. Test these areas for the expected coverage rate before general application. Allow for this increased surface area when determining material requirements.

Substrate Sq Ft/ Gallon
CMU & Block 60-90
Adobe Block & Natural Stone 80-100
Clay Brick 135-160
EIFS 90-130
Stucco 110-160
Concrete 145-170
Concrete Curing 320-420
Technical Data
Material Type Silane
Active Content 100%
Volume Solids 85%
Color of Material Milky White
Odor No Odor
VOC 30 g/L
Flash Point Non-Flammable
pH Value 6
Viscocity 9.6 Seconds No. 4 Ford Cup
Weight Approximately 8.8lbs per Gallon
Surface Dry/Recoat Approximately 1 Hour
Full Chemical Cure 5-7 Days


Test Data
ASTM C666 2200 Cycles- No Effect
ASTM C672 100 Cycles No Mass Loss, No Scaling
ASTM D2243 Do Not Freeze
ASTM G154 2,500 Hours No Loss in Repellency
Wind Driven Rain ASTM E-514-86., 98.7% Leak Red
Water Pen Fed Spec SS-W-110C, 75% Min Req, 96.8 Leak Red Chloride Ion Intr
Salt Pounding NCHRP No. 244 Series IV – 95% Red

No. 244 Series II – 87% Red

Chloride Ion Absorption No. 244 Series II – 87%
Water Abs CMU ASTM C140-75 98.6% Effective
Water Vapor Trans ASTM D-1653-71 100% Vapor Perm
Water Repellency ASTM C67-87 98.6% Effective
Weathering ASTM G-53 3,500 Hours – No Change
Surface Burning ASTM E84 Flame Spread 0, Smoke Development 0


Approvals & Qualifications
LAUSD – OESH Approved
USGBC – LEED Points Up to 3 Points
LEED (New Construction) Approved
LEED (New Schools/CHPS) Approved
CARB Approved
SCAQMD Approved
FDA Meets Requirements
USDA Meets Requirements


Surface Preparation: Prior to application, all surface shall be clean and dry with no oils, dirt, debris, or minerals such as efflorescence, lime and calcium. These stains, along with others, will prevent proper penetration of Micro-Seal® SiH4 to sufficiently seal for the warranty period. The use of Rainguard’s Restore-N-Prep™ Concrete and Masonry Cleaner system is recommended as a pretreatment to clean masonry surfaces. Once clean, allow the surface to fully dry before sealing or applying a topcoat (See the Restore-N-Prep™ TDS for details).

Application Instructions
1. Apply Micro-Seal® SiH4 using a hand pumped garden sprayer (do not atomize) or low-pressure airless spray equipment.
2. If using airless spray equipment we recommend a spray tip size of .035 to .051. Spray head should be held 8 to 12 inches from the surface.
3. Apply a flood coat to the point of saturation. This is achieved when the material is dripping 8-12 inches from the point of application.
4. Apply material following the coverage rate previously listed (P.1).
5. Avoid application in windy weather.
6. Trigger gun off at the end of each pass to avoid using excessive materials.
7. Multiple coats may be applied. Whitening or yellowing will not occur.


Safe Handling: Use product only with adequate ventilation and/or an appropriate cartridge type respirator. Avoid contact with skin and wear protective gloves. Read the Safety Data Sheet before using.

Precautions: Use material in a well-ventilated area. Protect the work of other trades. Protect shrubbery and other plants with drop cloths. Protect automobiles and all other areas not to be coated from overspray. Remove overspray from any windows, automobiles, metal, etc. as soon as possible should it occur. To prevent permanent staining, clean spills or leaks in a timely manner. All surfaces to be coated should be clean of any dirt and grime, efflorescence, lime run, form oils and release agents, grease, mud, excess mortar, and mold and mildew,etc. All cracks should be pointed or caulked. All voids, beeholes, masonry surface defects and openings such as
conduits, pipes, drains, door frames, vents, air conditioner openings, electrical openings, control joints, or any dissimilar materials should be repaired using urethane or other approved patching.

Do not apply to surfaces if moisture content is greater than 25% as measured with an electronic moisture meter. Do not apply materials in climates where freezing temperatures have existed prior to application. Allow adequate time for surfaces to thaw. Establish that air, surface, and material temperatures are above 40°F  (4.4°C) and at least 5°F above the dew point prior to painting. Do not apply at temperatures below 40°F when temperatures are expected to drop below 40°F within 48 hours of application. Do not apply if rain, snow, or lower temperatures are expected within 48 hours. Do not apply if relative humidity is greater than 90%.

Clear water repellents are not designed to waterproof horizontal masonry surfaces such as ledges, sills, cornices and parapet walls, etc.

Store materials in a well-protected area at 45°- 90°F. Avoid freezing temperatures, direct sunlight, and moisture. Keep away from heat sources.


NOTICE TO BUYER: DISCLAIMER OF WARRANTIES AND LIMITATIONS ON OUR LIABILITY We warrant that our products are manufactured to strict quality assurance specifications and that the information supplied by us is accurate to the best of our knowledge. Such information supplied about our products is not a representation or a warranty. It is supplied on the condition that you shall make your own tests to determine the suitability of our product for your particular purpose. Any use or application other than recommended herein is the sole responsibility of the user. Listed physical properties are typical and should not be construed as specifications. NO WARRANTY IS MADE, EXPRESSED OR IMPLIED, REGARDING SUCH OTHER INFORMATION, THE DATA ON WHICH IT IS BASED, OR THE RESULTS YOU WILL OBTAIN FROM ITS USE. N0 WARRANTY IS MADE, EXPRESSED OR IMPLIED, THAT OUR PRODUCT SHALL BE MERCHANTABLE OR THAT OUR PRODUCT SHALL BE FIT FOR ANY PARTICULAR PURPOSE. NO WARRANTY IS MADE THAT THE USE OF SUCH INFORMATION OR OUR PRODUCT WILL NOT INFRINGE UPON ANY PATENT. We shall have no liability for incidental or consequential damages, direct or indirect. Our liability is limited to the net selling price of our product or the replacement of our product, at our option. Acceptance of delivery of our product means that you have accepted the terms of this warranty whether or not purchase orders or other documents state terms that vary from this warranty. No representative is authorized to make any representation or warranty or assume any other liability on our behalf with any sale of our products. Our products contain chemicals that may CAUSE SERIOUS PHYSICAL INJURY. BEFORE USING, READ THE MATERIAL SAFETY DATA SHEET AND FOLLOW ALL PRECAUTIONS TO PREVENT BODILY HARM.