Two criteria to look for before we jump to the list of products.
Class 1 is the best type of vapor barrier, it is the only class that is allowed to use in crawl space by code. It is also called vapor retarder. The thing that matters in vapor barriers the most is perm rate, stands for moisture permeability (the less the better) and class 1 has 0.1 perm or less.
Thickness metters, we recommend 10-12 mil thick vapor barrier, in some terrains 20-mil. Do not go with 6-mil, it is widely accessible and quite popular, but it does not get the job done.
Premium Class 1 vapor barriers for crawl spaces
Stego Industries StegoCrawl 15-Mil
Perm rating: less then 0.010 perms (Class A)
Thickness: 15 mil virgin polyolefin
Puncture resistance: 203.8 newtons push-through
Compliance: ASTM E1745 Class A
Warranty: Life of Building Warranty
Best use: High-performance crawl space encapsulation, rocky or debris-laden ground conditions
Key advantage: Multi-layer construction eliminates need for string reinforcement while maintaining superior puncture resistance
Tu-Tuff Cross-Laminated Vapor Barrier
Perm rating: 0.00741 perms
Thickness: 4 mil (performance equivalent to 6-mil standard)
Tensile strength: 8,507 psi (3.6x stronger than standard barriers)
Puncture resistance: 275.8 beach units (6.4x more resistant)
Material: Cross-laminated virgin poly from high-density resins
Best use: Challenging conditions with sharp aggregate or construction traffic
Key advantage: Pinhole-free construction delivers maximum performance in minimal thickness
Rocky or debris-laden ground: Tu-Tuff provides maximum puncture resistance in minimal thickness.
Stego Wrap 20-Mil Premium
Perm rating: less then 0.01 perms
Thickness: 20 mil
Puncture resistance: >3,500 grams
Applications: Data centers, hospitals, critical infrastructure
Best use: Maximum protection environments requiring zero moisture migration
Key advantage: Highest puncture resistance available, engineered for extreme conditions
High-performance residential systems
Americover Pro Crawl Anti-Mold
Perm rating: 0.022 perms
Thickness: 10 mil equivalent performance
Special feature: State-of-the-art mold prevention technology
Material: Virgin resin construction with high-gloss white finish
Best use: Moisture-prone areas with mold concerns
Key advantage: Integrated anti-microbial properties beyond vapor control
High-moisture basements: combines vapor control with integrated mold prevention technology.
Key technical considerations
ASTM E1745 Class A compliance represents the current best practice, requiring minimum 45 lb/inch tensile strength and 2,200 grams puncture resistance alongside ≤0.1 perm ratings.
Virgin resin versus recycled content significantly impacts long-term performance. Virgin polyolefin and LLDPE materials demonstrate superior puncture resistance and aging characteristics compared to recycled content alternatives.
Installation durability often determines real-world performance more than laboratory specifications. Class A materials justify higher upfront costs through reduced installation failures and long-term reliability.