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Siloxane sealers are the workhorse of brick waterproofing: they penetrate masonry and line the pores with a water-repellent layer that still lets vapor out. The best siloxane masonry sealer sheds water effectively, leaves no visible film and lasts for years.
We compared pure siloxanes and silane/siloxane blends for brick walls, chimneys, block and paving.
Quick Answer: The Best Siloxane Masonry Sealer
- Best Overall: Prosoco Sure Klean Weather Seal Siloxane PD Water Repellent (1 gal)
- Best Widely Available: Drylok Siloxane 7 Brick & Masonry Penetrating Sealer (1 gal)
- Best for Chimneys: MasonryDefender Chimney Brick Sealer, Clear Water-Based Siloxane (1 gal, 2-Pack)
- Best Value Two-Pack: MasonryDefender Deep Penetrating Silane Siloxane Water Repellent (1 gal, 2-Pack)
- Best Silane/Siloxane Blend: Siloxane 9500 Ready-to-Use Silane/Siloxane Penetrating Sealer (1 gal)
- Best Sprayer: Chapin 25020 2-Gallon Clean ’N Seal Poly Deck Sprayer for Cleaners and Sealers
Prosoco Siloxane PD is the best siloxane masonry sealer for brick walls; Drylok Siloxane 7 is the best widely available option, and MasonryDefender’s chimney siloxane is the best for chimneys.
Best Siloxane Masonry Sealer Comparison Table
| Product | Best For | Type | Key Feature | Buy |
|---|---|---|---|---|
| Prosoco Sure Klean Weather Seal Siloxane PD Water Repellent (1 gal) | Best Overall | Penetrating siloxane water repellent | Breathable, invisible water repellent | Check Price |
| Drylok Siloxane 7 Brick & Masonry Penetrating Sealer (1 gal) | Best Widely Available | Penetrating siloxane sealer | Penetrating, traffic-rated per listing | Check Price |
| MasonryDefender Chimney Brick Sealer, Clear Water-Based Siloxane (1 gal, 2-Pack) | Best for Chimneys | Penetrating siloxane sealer | Breathable siloxane for chimneys | Check Price |
| MasonryDefender Deep Penetrating Silane Siloxane Water Repellent (1 gal, 2-Pack) | Best Value Two-Pack | Silane/siloxane penetrating sealer | Deep penetrating water repellent | Check Price |
| Siloxane 9500 Ready-to-Use Silane/Siloxane Penetrating Sealer (1 gal) | Best Silane/Siloxane Blend | Silane/siloxane penetrating sealer | DOT-approved per listing, salt and water repellent | Check Price |
| Chapin 25020 2-Gallon Clean ’N Seal Poly Deck Sprayer for Cleaners and Sealers | Best Sprayer | Pump sprayer | 2-gal sprayer made for sealers | Check Price |
The 6 Best Siloxane Masonry Sealers
Our picks for the best siloxane masonry sealer.
Prosoco Sure Klean Weather Seal Siloxane PD Water Repellent (1 gal)
1Prosoco’s Siloxane PD is a professional penetrating water repellent for brick and masonry walls.
👍 Pros & Cons
Pros
- Pro brand used on brick facades
- Breathable, does not trap moisture
- Natural, non-glossy look
Cons
- Not a stain or color
- Needs dry, clean brick
📄 Detailed Review
- Type: Penetrating siloxane
- Finish: Invisible / natural look
- Base: Water-based
- Best for: Exterior brick and masonry walls
Penetrating siloxanes soak into masonry and make it shed water while still letting vapor escape, which is why they are favored for exterior brick and chimneys.
Apply to dry, clean brick and follow the label’s saturation directions.
Drylok Siloxane 7 Brick & Masonry Penetrating Sealer (1 gal)
2Drylok Siloxane 7 is a widely available penetrating sealer for brick and masonry, including traffic surfaces.
👍 Pros & Cons
Pros
- Trusted masonry waterproofing brand
- Listed for vehicle traffic
- Penetrating, breathable
Cons
- Goes on milky white
- Two coats may be needed on porous brick
📄 Detailed Review
- Type: Penetrating siloxane
- Finish: Clear when dry (goes on milky)
- Base: Water-based
- Best for: Brick, pavers, masonry
It goes on milky and dries clear. Penetrating formulas protect without the slippery film of acrylics.
Do a test patch to check the final look.
MasonryDefender Chimney Brick Sealer, Clear Water-Based Siloxane (1 gal, 2-Pack)
3A breathable siloxane sealer marketed specifically for chimney brick.
👍 Pros & Cons
Pros
- Made for chimneys
- Breathable waterproofer
- Clear
Cons
- Does not fix cracked crowns or flashing
- Two-gallon pack
📄 Detailed Review
- Type: Penetrating siloxane
- Finish: Clear
- Base: Water-based
- Best for: Chimneys and exterior vertical masonry
Chimneys need breathable sealers so moisture inside the masonry can escape.
Repair crowns, flashing and mortar first.
MasonryDefender Deep Penetrating Silane Siloxane Water Repellent (1 gal, 2-Pack)
4MasonryDefender’s silane siloxane is a deep penetrating water repellent sold in a two-gallon pack.
👍 Pros & Cons
Pros
- Deep penetrating formula
- Two gallons per order
- Breathable
Cons
- Two-pack is more than small jobs need
- Not for glossy look
📄 Detailed Review
- Type: Silane/siloxane penetrating
- Finish: Natural look
- Base: Water-based
- Best for: Concrete, brick, block
Good for larger walls, block and concrete where you want water beading without changing the look.
Spray with a low-pressure pump sprayer.
Siloxane 9500 Ready-to-Use Silane/Siloxane Penetrating Sealer (1 gal)
5A ready-to-use silane/siloxane penetrating sealer listed for pavers, brick and stone.
👍 Pros & Cons
Pros
- Silane/siloxane blend penetrates deep
- Salt and water repellent
- Listed coverage 150-400 sq ft per gallon
Cons
- Coverage varies with porosity
- No color enhancement
📄 Detailed Review
- Type: Silane/siloxane penetrating
- Finish: Natural look
- Base: Water-based, ready to use
- Best for: Pavers, driveways, brick, stone
Silane/siloxane blends penetrate dense and porous masonry, useful in freeze-thaw areas where salt and water cause spalling.
Apply until the surface is evenly wet, avoiding puddles.
Chapin 25020 2-Gallon Clean ’N Seal Poly Deck Sprayer for Cleaners and Sealers
6Chapin’s Clean ’N Seal is built for applying cleaners and transparent sealers.
👍 Pros & Cons
Pros
- Designed for transparent sealers and cleaners
- Fan tip for even coats
- Poly tank resists corrosion
Cons
- Seals may not suit strong solvents
- Pumping needed
📄 Detailed Review
- Capacity: 2 gallons
- Tank: Poly
- Best for: Water-based sealers and cleaners
A low-pressure sprayer with a fan tip lays down even, flood-style coats of penetrating sealer.
Rinse thoroughly after each use.
How We Chose the Best Siloxane Masonry Sealer
To choose the best siloxane masonry sealer, we compared siloxane and silane/siloxane products by substrate suitability, how they describe breathability and appearance, coverage and ease of application.
Breathable sealers help masonry stay dry; see the EPA guide to mold and moisture.
Product details in this guide come from manufacturer specifications and patterns in verified owner feedback; we do not claim hands-on testing we have not done. Read more on our How We Test page.
Buying Guide: Best Siloxane Masonry Sealer
Tips for the best siloxane masonry sealer.
How siloxane works
It penetrates pores and leaves a water-repellent lining, not a surface film.
Breathable
Water vapor can still escape, reducing freeze-thaw and spalling risk.
Best on brick and block
Siloxanes suit porous vertical masonry especially well.
Blends for dense surfaces
Silane/siloxane blends penetrate denser concrete and pavers.
Water-based options
Many siloxanes are water-based and low odor.
Not for painting over
Siloxane-treated surfaces usually resist paint adhesion.
Applying Siloxane Sealer
For best results.
- Repair cracks and joints first.
- Apply to clean, dry masonry.
- Flood on at low pressure.
- Keep off rain for the label’s dry time.
Questions about the best siloxane masonry sealer:
Frequently Asked Questions
What is the best siloxane masonry sealer?
The best siloxane masonry sealer is Prosoco Siloxane PD, with Drylok Siloxane 7 as a widely available alternative.
Is siloxane better than acrylic?
For exterior brick, yes; it is breathable and invisible.
How long does siloxane last?
Often several years.
Can siloxane be used indoors?
Yes, though dust control may need a film sealer.
Does siloxane darken brick?
Usually very little; test first.
Final Verdict
Our final pick for the best siloxane masonry sealer is the Prosoco Siloxane PD. Choose the Drylok Siloxane 7 if you want a widely available option, or the MasonryDefender Chimney Sealer for chimneys.
Related Guides
More masonry sealer guides:
- Best Faux Brick on Amazon
- Best Masonry Sealer for Leaking Chimney
- Best Masonry Waterproofing Sealer
- Best Masonry Sealer for Concrete Block
- Best Penetrating Masonry Sealer
Product details are based on manufacturer specifications at the time of writing. Prices and availability change often, so check Amazon for the latest price.
