Imagine your home’s exterior. Those sturdy concrete blocks might look tough, but they’re actually pretty thirsty! Over time, rain, sun, and even everyday dirt can soak into them, leading to cracks, stains, and a dull, worn-out look. But what if there was a simple way to protect that investment and keep your home looking its best for years to come?
Choosing the right sealer for your exterior concrete blocks can feel like a guessing game. You want something that works, but with so many products out there, how do you know which one is best? You might worry about it not lasting, or even making your blocks look weird. This can be frustrating, and you just want to protect your home without the headache.
Don’t worry! This guide is here to help. We’ll break down what makes a good exterior concrete block sealer and show you how to pick the perfect one for your needs. By the end, you’ll feel confident in your choice and ready to give your home’s exterior the protection it deserves, saving you time and money down the road.
Top Exterior Concrete Block Sealer Recommendations
- EXTREME WEATHER PROTECTION: Maintain your stone, concrete, exterior wood, brick, and more from water damage. Our wood and masonry sealant safeguards and creates a strong and effective shield against extreme weather conditions. Utilizing professional grade waterborne silicone technology, our sealant offers long-lasting protection against moisture to maintain a natural appearance.
- LONG LASTING: Drying completely invisible, our wood sealant encourages a natural appearance and beauty for years to come. The granite sealant prevents water seepage, and water beads up while waterproofing.
- MADE IN THE USA: Our solution is made in the USA and penetrates deep to develop a long-term protective shield against even the harshest of meteorological conditions. Our high quality, state-of-the-art sealant gets the job done right the first time.
- MULTI-SURFACE SEALANT: Formulated to protect stone, concrete, wood, brick, block, stucco, and much more, conveniently and effectively seal and protect a large plethora of surfaces with our floor sealer. This sealant is VOC Compliant.
- EASY TO APPLY: Mix ProCare's Wooden Floor Sealer before use. Apply our hardwood sealer using a pump or airless sprayer, paint pad, brush, or roller. Our floor finish and sealer should be applied evenly until the surface is completely saturated while avoiding puddling
- SILANE SILOXANE DEEP PENETRATION: This penetrating concrete sealer uses a silane siloxane formula that soaks deep into porous surfaces instead of sitting on top, helping reduce water and moisture absorption on driveways, patios, sidewalks and other exposed concrete and masonry. Buyers sealing a 30-year-old driveway see water bead up after the first rain rather than soaking in.
- CLEAR, BREATHABLE NATURAL LOOK: This clear concrete sealant protects outdoor surfaces while preserving their original appearance. The breathable, vapor-permeable formula lets trapped moisture escape and does not create a heavy glossy wet look, so it suits concrete, pavers, brick and stone where you want the natural color to stay.
- FOR CONCRETE, BRICK, PAVERS & STONE: One versatile cement sealer for concrete and masonry covers porous exterior surfaces including driveways, patio pavers, walkways, pool decks and compatible stone. It also works as a garage floor sealer and driveway sealant on properly prepared surfaces. Not intended for glazed or non-absorbent surfaces.
- BUILT FOR OUTDOOR WEATHER EXPOSURE: Designed to help limit moisture intrusion from rain, snow and changing seasonal conditions while allowing trapped moisture vapor to escape. The siloxane concrete sealer resists deicing salts and chlorides that cause surface spalling, and helps protect against freeze-thaw damage on exposed concrete, brick, pavers and stone.
- EASY DIY APPLICATION, NO DILUTION: The low-viscosity liquid is ready to use and designed to penetrate rather than sit as a thick coating. Apply this concrete sealer spray with a low-pressure sprayer, roller or brush to a clean, dry, properly prepared surface. One gallon covers up to 200 sq ft depending on surface porosity; buyers report about 160 sq ft with a quarter left over.
- A CHIMNEY SEALANT WITH ENDURING PERFORMANCE: This brick protector creates a permanent bond with your chimney’s masonry for durable protection. It allows trapped moisture to escape, preventing freeze/thaw damage and ensuring lasting effectiveness
- SILOXANE BRICK SEALER PREVENTS LEAKS: Chimney waterproofing is important because cracks in your chimney can let water seep into the home; this water repellent effectively seals & waterproofs your chimney, protecting your home from water intrusion
- BREATHABLE BRICK SEALER EXTERIOR PROTECTION: This non-film forming sealant spray offers breathable, superior protection without altering surface color for residential chimneys, brick walls, and vertical masonry surfaces like stone, stucco, and more
- EASY APPLICATION WATER-BASED CHIMNEY WATERPROOFING SEALANT: Apply 2 coats of chimney sealer with a pump-up sprayer while using drop cloths to prevent overspray, but product is water based & VOC compliant, so it’s easy to clean up
- COVERAGE & DRY TIME: Our siloxane brick sealer covers 80-150 sq. ft. per gallon (2 coats). Dries to touch in 2-6 hours after you spray sealer. Waterproof in 4-6 hours, with continued strengthening over several weeks
- Turbo wet look sealer protects exterior concrete/masonry surfaces for ultimate durability
- Long lasting, solvent-based turbo spray seals and enhances masonry, pavers, natural stone and decorative concrete
- Innovative Turbo Spray System offers 4X greater output than traditional waterproofer sprays with up to 10" wide fan spray; ready for light foot traffic after 2 hours
- UV and weather resistant concrete sealant extends the life of concrete with a "wet look" finish
- High gloss wet look lacquer spray works faster than a traditional pump sprayer for easy application
- Waterproofing Protection with Nanotechnology: Engineered with advanced nanotechnology to create a powerful water barrier—KILZ waterproofing paint blocks up to 12 PSI of water pressure to help stop water infiltration on concrete and masonry surfaces.
- Interior & Exterior Versatility: Ideal for both indoor and outdoor use—protects basement walls, masonry walls, stucco, brick, concrete blocks, and retaining walls. For below below-grade application, fill all holes/cracks with hydraulic cement prior to painting. Not for use on floors or on walls with active water leaks.
- Resistant & Alkali Resistant Finish: Formulated for high moisture areas, the resistant paint finish also resists alkali buildup, ensuring a long-lasting, decorative, and durable finish that stands up to tough basement and outdoor conditions.
- Low Odor & Easy to Apply: This low-odor formula is easy to apply, dries to the touch in 1 hour, and ready for recoat in just 4 hours. Fully cures in 7–14 days for washable, durable protection.
- Trusted KILZ Quality: Backed by over 50 years of expertise in surface coatings, KILZ products create long-lasting results you can be proud of for many years to come.
- Interior/Exterior use on new or previously painted drywall, concrete, wood, masonry, metal and glossy or difficult surfaces
- Water-based formula seals uniformly and will stick to surface without sanding
- Dries to the touch in just 30 minutes, ready to recoat in 1 hour and covers up to 100 sq. ft.
- Has excellent stain blocking resistance and can be used over any oil or latex topcoat
- Gray color of primer works great under vibrant, vivid colors saving time and money by improving hide and coverage of deep topcoats
- Flows well into cracks
- Blends with the natural color of concrete
- Use for repairing cracks in concrete sidewalks, patios and driveways
- 946 ml
- Pour directly from the bottle
- Strong and Highly Adhesive Elastomeric Liquid Rubber Waterproofer: Ames Blue Max is a durable blue coating with 1200% elongation that resists cracking and peeling, suitable for waterproofing above and below-grade basements and foundations, insulated concrete forms, and underlayment
- Versatile Application as Primer and Waterproofer: Blue Max Liquid Rubber Waterproofer can be used as a primer on most types of roofs including metal roofs and RV roofs. Use on concrete, wood, metal and more. Brush, roll or spray on vertical or horizontal surfaces
- Elastomeric Membrane with Superior Flexibility: Blue Max is an elastomeric membrane that expands and contracts 1200% with surface to resist cracking and peeling. Blue Max is a special blend of adhesive, high strength elastomeric liquid rubber for waterproofing concrete, wood, metal and more
- Non-Toxic and VOC Compliant Formula: Blue Max is non-toxic, VOC compliant in all 50 states and made in the USA. Ames is a Veteran Founded company.
- Convenient 1 Gallon Packaging: Ames Blue Max Liquid Rubber Waterproofer is packaged in a 1 gallon pail with blue colored formula.
Protect Your Project: The Ultimate Exterior Concrete Block Sealer Buying Guide
Want to keep your concrete block walls looking great and lasting longer? An exterior concrete block sealer is your best friend. It shields your blocks from rain, stains, and the harsh sun. This guide will help you pick the right one for your needs.
Why Seal Your Concrete Blocks?
Concrete blocks might seem tough, but they can soak up water and stains. Sealing them creates a protective barrier. This barrier stops water from seeping in, which can cause cracks when it freezes and thaws. It also makes cleaning up spills much easier. Your walls will look newer for longer, and you’ll save money on repairs down the road.
Key Features to Look For
When you shop for a sealer, keep these important features in mind:
1. Water Repellency
This is the most important job of a sealer. Look for products that clearly state they are “water repellent” or “waterproof.” This means they actively push water away from the surface.
2. Stain Resistance
Concrete blocks can get dirty from dirt, oil, or mildew. A good sealer will make it harder for these things to stick. This keeps your walls looking clean with less scrubbing.
3. Breathability
This might sound strange, but some sealers let moisture escape from inside the block. This is important because trapped moisture can cause damage. Look for “breathable” or “vapor permeable” on the label.
4. UV Protection
The sun’s rays can fade and degrade concrete. Some sealers have UV blockers that help protect the color and integrity of your blocks.
5. Durability and Longevity
How long will the sealer last? Some sealers need reapplication every year or two. Others can last for five years or more. Check the product description for expected lifespan.
6. Finish Type
Do you want your blocks to look natural, or do you prefer a glossy sheen? Sealers come in matte, satin, and gloss finishes. Choose one that matches your desired look.
Important Materials and What They Mean
The ingredients in a sealer are key to how well it works.
- Acrylics: These are common and work well for general protection. They offer good water and stain resistance.
- Silicones/Siloxanes: These are excellent for deep penetration and offer superior water repellency. They are often more breathable.
- Polyurethanes: These create a tough, durable film that offers great abrasion and chemical resistance. They can sometimes make the surface slippery.
Factors That Improve or Reduce Quality
A sealer’s quality depends on a few things.
- Better Quality:
- High concentration of active ingredients: More of the good stuff means better protection.
- Penetrating formulas: These soak into the block for longer-lasting defense.
- Reputable brands: Established companies often use better research and development.
- Lower Quality:
- Water-based formulas with low solids: These might not offer as much protection or last as long.
- Surface-only sealers: These can wear off quickly with foot traffic or weather.
- Unlabeled or generic brands: You might not know what you’re getting.
User Experience and Use Cases
Most sealers are pretty easy to use. You usually apply them with a brush, roller, or sprayer. Always follow the product’s instructions carefully.
- DIYers: Many sealers are designed for homeowners to use themselves.
- Homeowners: Protect your foundation walls, garden walls, patios, and walkways made of concrete blocks.
- Landscapers: Keep decorative block walls and planters looking their best.
- Contractors: Ensure long-term protection for new construction projects.
Frequently Asked Questions (FAQ)
Q: What are the main Key Features to look for in an exterior concrete block sealer?
A: The main Key Features are excellent water repellency, strong stain resistance, breathability to allow moisture to escape, UV protection from the sun, and long-lasting durability.
Q: What are the important materials used in concrete block sealers?
A: Important materials include acrylics, silicones/siloxanes, and polyurethanes. Each offers different levels of protection and performance.
Q: How can I tell if a sealer is good quality?
A: Good quality sealers usually have a high concentration of active ingredients, are designed to penetrate the block, and come from trusted brands.
Q: What factors can make a sealer perform poorly?
A: Poor quality can result from low concentrations of active ingredients, formulas that only seal the surface, or products from unknown brands.
Q: How do I apply an exterior concrete block sealer?
A: You typically apply sealers with a brush, roller, or sprayer. Always read and follow the specific product instructions for best results.
Q: Can I use any sealer on any type of concrete block?
A: It’s best to check the product label to ensure it’s suitable for your specific type of concrete block and its intended use.
Q: How often do I need to reapply concrete block sealer?
A: This varies by product. Some need reapplication every 1-2 years, while others can last 5 years or more. Check the product’s expected lifespan.
Q: Will a sealer change the look of my concrete blocks?
A: Yes, sealers can affect the look. They come in different finishes like matte, satin, or gloss. Some may darken the block slightly.
Q: Can I seal concrete blocks that are already stained?
A: It’s always best to clean the blocks thoroughly before sealing. Some sealers might help repel future stains, but they won’t typically remove existing ones.
Q: Is it important for the sealer to be breathable?
A: Yes, breathability is important. It allows any moisture trapped inside the block to escape, preventing damage like cracking or spalling.