Choosing the right materials is half the battle in effective waterproofing. Compound asphalt felt base mats are increasingly used as a high-performance base sheet in both new builds and retrofits. Here’s a practical guide on how to choose, apply, and maintain this essential waterproofing layer.
1. Choosing the Right Type
Not all base mats are created equal. When selecting one, consider:
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Reinforcement Type: Polyester mats are more flexible; fiberglass offers better dimensional stability.
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Thickness and Weight: Thicker mats typically provide better durability and puncture resistance.
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Coating Compound: Look for SBS or APP-modified asphalt for enhanced performance in hot or cold climates.
2. Application Techniques
Compound asphalt felt base mats can be applied via:
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Torch-On Method: Common in roofing; requires skilled labor and safety measures.
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Self-Adhesive Systems: Ideal for enclosed or sensitive areas where open flame is not permitted.
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Hot-Mopped or Cold-Applied Adhesives: Suitable for large horizontal surfaces like foundations or decks.
Best Practices:
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Ensure substrate is clean and dry before installation
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Overlap seams appropriately (usually 75–100 mm)
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Use proper primers and edge sealants for long-term performance
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Always follow manufacturer’s guidelines
3. Maintenance and Inspection
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Inspect for blisters, punctures, or seam separations at least annually
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Repair any damage with compatible patching materials
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Maintain proper drainage to reduce hydrostatic pressure and ponding
4. Common Mistakes to Avoid
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Skipping surface prep
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Installing during wet or freezing conditions
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Not allowing for thermal expansion
Conclusion
Compound asphalt felt base mats offer reliable and long-lasting waterproofing when installed correctly. By understanding the material’s characteristics and following best practices, you can significantly extend the life of your waterproofing system.
