Prepared by: A-Plus Buddy Eric & A-Plus Buddy Ela
Last updated: Jul 28, 2025
One of the Most Effective Ways to Waterproof Your New Firewall!
When building a new home, choosing the right waterproofing product is one of the most critical decisions—especially during the finishing phase of construction. Your home is a long-term investment, and proper waterproofing ensures that it stays protected from rain, leaks, and long term structural damage.
For firewalls and other exterior surfaces, positive side cementitious waterproofing—like A Plus® Concrete Bond—remains one of the most trusted, effective, and cost-efficient options on the market today.
Read on to discover how this system works and how to use it properly to get the best results!
What is Positive Side Waterproofing?
Positive side waterproofing is applied to the exterior side of a wall, which is the side directly exposed to water, such as rain. It prevents water from entering the substrate (concrete or masonry) and protects the inner, occupied spaces of your home.
This method is considered the first line of defense in new constructions—ideal for areas like firewalls, balconies, and roof decks.
By contrast, negative side waterproofing is applied inside the building, to walls that aren’t directly exposed to water. This is often used when there’s no access to the outer wall—such as firewalls built too close to a neighbor’s structure.
➡️ In simple terms:
- Positive Side = Waterproofing applied before water can enter (e.g. outer wall hit by rain)
- Negative Side = Waterproofing applied after water has already passed through the wall (e.g. inner wall inside your house)
While negative side waterproofing can still hold back water from entering your home, it doesn’t stop moisture from entering the concrete itself, which may lead to long-term issues such as corrosion of steel reinforcements.
What is Cementitious Waterproofing?
Cementitious waterproofing is a popular type of positive side waterproofing that’s mixed with cement before application—hence the name “cementitious.”
Compared to other positive side options like acrylics, polyurethanes, and sheet membranes, cementitious waterproofing is often more accessible, easy to use, and cost-effective for homeowners and contractors alike.
One of the top choices in this category is A-Plus® Concrete Bond.
🔧 How to Use A-Plus® Concrete Bond: Step-by-Step
Protect your firewall or any exterior wall from extreme weather conditions with this easy, step-by step guide:
- Curing or Sealing:
- Let new concrete cure for at least 4 weeks.
- Alternatively, apply 2 coats of A-Plus® Concrete Sealer.
- Allow 1–2 hours drying time between each coat.
- Waterproofing:
- Mix 1 liter of A-Plus® Concrete Bond with 1 kg of Portland cement.
- Apply 3–4 coats of the mixture.
- Allow 2–3 hours drying time between each coat.
- ⚠️Important: The mixture has a pot life of approximately 4 hours—only mix what you can use within this time.
- Surface Preparation:
- Repair cracks and surface imperfections with A-Plus® Concrete Putty.
- For a smooth, even finish, apply A-Plus® Skimcoat 501 or 503.
- Topcoat Application:
- Once the waterproofing has fully dried, apply your topcoat of choice.
- For firewalls and exterior surfaces, we recommend A-Plus® All Weather Paint.
- Apply 2–3 coats using a brush, roller, or spray.
- Allow 2–3 hours drying time between each coat.
Where Else Can You Use A-Plus® Concrete Bond?
You can use A-Plus® Concrete Bond on many other surfaces where direct exposure or contact with water might pose a risk for water entry and where a positive side cementitious water proofing is the ideal choice such as:
Roof decks
Bathrooms
Balconies
⚠️Reminders for Best Results
✅ Always finish surfaces applied with Concrete Bond with a topcoat. Leaving it bare may cause cracks and reduce waterproofing effectiveness.
⏳ Mix only what you can use within 4 hours.
❌ Do not dilute with water or solvents. Only mix with Portland cement.
🧽 Remove any existing paint completely before applying waterproofing.
📝 Follow the manufacturer’s recommended system and ratio—this varies per product and is critical to ensure long-term performance.
In summary, just remember:
Waterproofing your new firewall is an essential step in protecting your dream home. With the reliable, effective, and easy-to-apply A-Plus® Concrete Bond, you’re taking a smart step toward long-lasting protection.
A-PLUS® CONCRETE BOND ANG SOLUSYON SA TULO MO!
