Base Layer Rules for Exterior Wall Putty

Choosing quality exterior wall putty is essential—but it’s useless without a up-to-standard base layer. A flawed base can cause cracking, peeling, or hollowing, ruining the wall’s durability. Below are the must-follow base layer requirements for smooth, long-lasting putty application, plus key details about the putty itself.

1. Non-Negotiable Base Layer Standards

• Solid, even, smooth surface: Repair all cracks first—unfixed cracks will show through the putty.

• No defects: No sanding marks, peeling, looseness, or hollowing. These create weak spots where putty can’t bond.

• Clean & grease-free: Remove all dust, debris, and grease. Even small oil/dirt residues block adhesion.

• Mold-free: Eliminate mold completely (and fix its root cause, like leaks). Mold spreads through putty if left untreated.

• Moisture <10%: Use a moisture meter to confirm the base is fully dry. Residual moisture causes putty bubbling or cracking.

• pH <10: High alkalinity leads to efflorescence (white powder) or blooming, weakening adhesion. Test and neutralize if needed.

• Follow JGJ73-91: Comply with this exterior wall construction code. Never apply putty to an uninspected base.

2. Drying Time for New Bases

• Summer: At least 10 days (with good ventilation).

• Winter: Over 20 days (low temps slow evaporation; rushing causes moisture issues).

3. What Makes Good Exterior Wall Putty?

• Strong performance: High adhesion, impermeability (blocks water), and resistance to wall micro-cracks. It won’t shrink, keeping the finish smooth.

• Eco-friendly & easy to use: Non-toxic for workers and the environment. Most are single-component—just add water and stir.

• Durable ingredients:

• Polymers like RDP (redispersible polymer powder) boost adhesion and flexibility.

• Cellulose ethers (e.g., methyl cellulose ether) improve workability and water retention.

• Anti-cracking fibers (e.g., Dingqiang fibers, 1.5–3% by weight) add toughness and prevent cracking.

• Versatile: Replaces traditional mixes (talcum powder + sodium cellulose + 901 glue) and suits high-end spaces (clubs, hotels, homes) needing exterior water seepage protection.

Final Tip: Prioritize the Base