1. Introduction: Why Exterior Surfaces Need Elastomeric Protection
Exterior walls and roofs face constant attack: rain, UV radiation, temperature swings, and building movement. Over time, these elements cause cracking, spalling, and water infiltration that lead to costly structural damage.
AQUAFLEX 350 is a premium acrylic elastomeric waterproof coating designed to solve these problems. Unlike conventional paints that simply decorate, AQUAFLEX 350 forms a thick, flexible membrane that bridges cracks, repels water, and reflects heat.
Whether you are protecting a stucco villa, a concrete office building, or a metal roof, this guide covers everything you need to know about AQUAFLEX 350.
2. What is AQUAFLEX 350?
AQUAFLEX 350 is a 100% acrylic elastomeric coating formulated for exterior waterproofing. It is:
Elastomeric: The coating stretches and recovers with building movement.
Breathable: Allows trapped moisture vapor to escape, preventing blistering.
UV Resistant: Won’t chalk or fade under intense sun.
Water-Based: Low odor and easy cleanup with soap and water.
Common Names for This Product:
Elastomeric roof coating
Acrylic wall waterproof paint
Flexible masonry coating
Exterior crack bridge coating
AQUAFLEX 350 is a premium acrylic elastomeric waterproof coating designed to solve these problems. Unlike conventional paints that simply decorate, AQUAFLEX 350 forms a thick, flexible membrane that bridges cracks, repels water, and reflects heat.
Whether you are protecting a stucco villa, a concrete office building, or a metal roof, this guide covers everything you need to know about AQUAFLEX 350.
3. Key Features and Technical Specifications
Here are the verified specifications for AQUAFLEX 350, essential for engineers and specifiers:
| Parameter | Value | Test Method |
|---|---|---|
| Appearance | White and colors (tintable) | Visual |
| Solid Content | 60% ± 2% | ASTM D1644 |
| Tensile Strength | ≥ 2.0 MPa | ASTM D412 |
| Elongation at Break | ≥ 300% | ASTM D412 |
| Water Vapor Permeability | 5.5 perms (breathable) | ASTM E96 |
| Crack Bridging Ability | Up to 1.5 mm | ASTM C1305 |
| Solar Reflectance Index (SRI) | 104 (white) | ASTM E1980 |
| Application Temperature | +5°C to +40°C | – |
| Coverage Rate | 0.3 – 0.5 kg/m² per coat | – |
What These Numbers Mean for Your Project:
| Feature | Benefit |
|---|---|
| 300% Elongation | Coating moves with the building—no cracking during thermal expansion or minor settlement |
| 60% Solids | High film build means fewer coats to achieve desired thickness |
| SRI 104 (White) | Reduces roof surface temperature by up to 20°C, lowering cooling costs |
| Breathable (5.5 perms) | Preects concrete from freeze-thaw damage by allowing moisture escape |
4. AQUAFLEX 350 vs. Other Coatings: What's the Difference?
Many homeowners and contractors confuse elastomeric coatings with standard paint or silicone. Here is a quick comparison:
| Feature | AQUAFLEX 350 (Acrylic Elastomeric) | Standard Exterior Paint | Silicone Coating |
|---|---|---|---|
| Film Thickness | Thick (200-300 microns) | Thin (50-100 microns) | Thick |
| Elongation | 300% | < 10% (brittle) | Low (silicone is stiff) |
| Breathability | High | Medium | Zero (traps moisture) |
| Adhesion to Damp Surfaces | Good | Poor | Excellent |
| Recoatability | Excellent (overcoats itself) | Good | Difficult (silicone repels silicone |
When to Choose AQUAFLEX 350:
You need a breathable system (concrete, stucco, masonry)
You want to recoat in the future without complicated preparation
You are looking for a cost-effective solution for large areas
When to Consider Alternatives:
For ponding water (standing water on flat roofs) → consider TPO membrane or silicone
For heavy foot traffic → consider polyurethane coating (see ProFlex 2K)
5. Primary Applications: Where AQUAFLEX 350 Excels
5.1 Exterior Walls (Stucco, Concrete, Masonry)
This is the most common application for AQUAFLEX 350. Exterior walls are exposed to wind-driven rain, which can penetrate small cracks and cause efflorescence (white salt deposits) or spalling.
Why AQUAFLEX 350:
Bridges hairline cracks up to 1.5mm
Breathable—prevents trapped moisture behind the coating
Available in multiple colors (tintable)
Ideal Substrates:
Stucco and EIFS
Poured concrete
Concrete block (CMU)
Brick and masonry
Fiber cement board
For basement walls that are damp but not under hydrostatic pressure, AQUAFLEX 350 provides a decorative, waterproof barrier. For basements with active water leakage or negative side pressure, consider our K11 Flexible cementitious waterproofing coating which is designed to withstand hydrostatic pressure.
5.2 Low-Slope and Pitched Roofs
While primarily a wall coating, AQUAFLEX 350 is widely used on metal roofs, concrete tiles, and spray foam (SPF) roofs.
Advantages for Roofs:
Cool roof effect: White formulation reduces heat island effect and cooling costs
Seamless: Liquid-applied means no seams to fail (unlike sheet membranes)
Lightweight: Adds minimal weight to the structure
5.3 Balconies and Walkways (with Non-Slip Additive)
For pedestrian traffic areas, AQUAFLEX 350 can be mixed with silica sand to create a slip-resistant texture.
5.4 Interior Damp Walls (Basement Interior)
For basement walls that are damp but not under hydrostatic pressure, AQUAFLEX 350 provides a decorative, waterproof barrier.
6. Application Guide: How to Apply AQUAFLEX 350 Like a Pro
Proper application is key to achieving the 10-year expected service life. Follow these steps:
Step 1: Surface Preparation (60% of Success)
Cleaning: Remove all dirt, oil, efflorescence, and loose paint. Use a pressure washer (2000-3000 psi) for best results.
Repairs: Fill large cracks (> 3mm) with a suitable patching compound.
Mildew Treatment: If mildew is present, wash with a bleach solution (1 part bleach : 3 parts water) and rinse thoroughly.
Step 2: Priming (When Needed)
For highly porous surfaces (new stucco, concrete block), dilute AQUAFLEX 350 with 10-20% water as a primer coat.
For chalking surfaces, use an acrylic bonding primer first.
Step 3: Mixing
Stir gently with a paddle mixer on a low-speed drill. Do not thin unless specified.
Step 4: Application
Tools: 3/4″ nap roller (for rough surfaces), airless sprayer, or wide brush.
Number of Coats: Minimum 2 coats, preferably 3 for optimal protection.
Wet Film Thickness: Target 200-300 microns per coat.
Coverage: Approx. 4-5 m² per liter per coat (depending on texture).
Step 5: Curing
Allow 4-6 hours between coats (at 25°C, 60% humidity).
Protect from rain for 24 hours.
Full cure achieved in 7 days.
7. Color Options and Aesthetics
AQUAFLEX 350 is available in:
Stock White: Maximum solar reflectance
Custom Colors: Can be tinted to match architectural requirements
Color Selection Guide:
| Color | Best For | Note |
|---|---|---|
| White | Roofs, hot climates | Maximum energy savings |
| Light Beige/Tan | Walls, residential | Hides dirt better than white |
| Earth Tones | Architectural projects | Limited availability, may require custom order |
Important: Dark colors absorb more heat and may reduce the coating’s lifespan in direct sun. For roof applications, white or light colors are strongly recommended.
8. Maintenance and Longevity
Expected Lifespan:
Walls: 8-12 years
Roofs (white): 5-10 years (depending on UV exposure)
When to Recoat:
Coating shows chalking when rubbed with a dark cloth
Cracks reappear at substrate joints
Water no longer beads on the surface
Recoating: AQUAFLEX 350 adheres well to itself. Simply clean the surface and apply 1-2 fresh coats.
9. Frequently Asked Questions (FAQ)
Q1: Can AQUAFLEX 350 be applied over old paint?
Yes, provided the old paint is sound and well-adhered. Test by pressing duct tape onto the surface and pulling—if paint comes off, it needs to be removed.
Q2: Is AQUAFLEX 350 suitable for flat roofs with standing water?
For occasional ponding (less than 24 hours), yes. For constant standing water, consider a different system like TPO membrane or a silicone coating.
Q3: How is it different from AQUAFLEX 590 ECO?
| Product | Best For | Chemistry |
|---|---|---|
| AQUAFLEX 350 | Walls, roofs, general exterior | Acrylic elastomeric |
| AQUAFLEX 590 ECO | Potable water tanks, green roofs | Waterborne polyurethane |
Q4: Can I apply it in cold weather?
Minimum application temperature is +5°C and rising. Do not apply if freezing is expected within 24 hours.
Q5: How do I clean up?
Tools and equipment can be cleaned with soap and water while the coating is still wet.
Q6: What is the warranty?
AQUAFLEX 350 carries a 10-year limited warranty when applied according to specifications. Contact us for detailed warranty terms.
Q7: What’s the difference between AQUAFLEX 350 and K11 Flexible for basements?
A: Both can be used in basements, but they serve different purposes:
AQUAFLEX 350 is a film-forming acrylic coating. It’s ideal for damp walls where you want a decorative, breathable finish.
K11 Flexible is a cementitious coating that becomes part of the substrate. It’s better for actively leaking basements or areas with water pressure behind the wall.
For best results, some projects use K11 as a base layer and AQUAFLEX 350 as a topcoat for color.
10. Case Study: Exterior Wall Restoration in Coastal Climate
Project: 20-year-old stucco apartment complex in Miami, Florida
Problem: Cracks, water infiltration, fading paint
Solution: AQUAFLEX 350 applied over prepared stucco (2 coats)
Results:
Immediate stop to water leaks
15°C reduction in wall surface temperature (white color)
No cracking after 3 years, despite hurricane winds
11. Conclusion and Call to Action
AQUAFLEX 350 is the proven choice for architects, contractors, and homeowners seeking a durable, breathable, and cost-effective exterior waterproofing solution.
Whether you need to:
Waterproof a stucco wall
Protect a concrete roof
Restore an aging masonry building
Reduce cooling costs with reflective coating
AQUAFLEX 350 delivers professional results with simple application.
Ready to start your project?
- Contact Information: WhatsApp: +86-13153030995 E-mail: info@ylc-waterproofing.com