VaporBlock® Plus 20 Mil Vapor Barrier
$355.71
(Shipping included for all online orders within the continguous U.S.)
VaporBlock® Plus 20 Mil Vapor Barrier is one of the best under-slab vapor and gas barriers in the construction market. It offers superior protection against moisture and gas transmission. Protect indoor air quality from harmful gases and potential water damage from vapor migration.
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- Please call to order 10′ x 150′ rolls – ships with minimal lead times.
- Custom sizes are available with minimum volume requirements.
- Certified ASTM E-96 vapor retarder.
- Exceeds ASTM E1745 specification standards.
This product is American-made
Description
Technical Data
Applications
20-Mil Reinforced Vapor Barrier for Radon and Moisture Control
VaporBlock® 20 Plus is a 20-mil reinforced vapor barrier designed for under-slab and crawl space applications where moisture control and radon resistance are critical. Engineered for permanent installation, it delivers the durability, puncture resistance, and low vapor permeability required for inspection-driven projects and demanding jobsite conditions.
This heavy-duty vapor barrier is commonly specified for radon mitigation systems, new construction, and crawl space encapsulation, helping reduce ground moisture intrusion and soil gas migration when installed and sealed correctly.
🛡️ Built for permanent installation. Unlike thin or temporary plastic sheeting, VaporBlock® 20 Plus is engineered for long-term, inspection-ready results in residential and light commercial construction — over gravel, uneven substrates, and complex foundation layouts.
Key Features
Radon-Resistant Vapor Barrier
VaporBlock® 20 Plus helps reduce radon and soil gas migration through slabs and crawl spaces when used as part of a properly sealed system.
📖 Crawl Space Vapor Barriers for Radon Mitigation
Low Vapor Permeability for Moisture Control
By limiting ground moisture migration, VaporBlock® 20 Plus helps control humidity and reduce moisture-related risks, including mold growth and material degradation beneath slabs and in crawl spaces.
📖 Understand ASTM E-1745 and Why It Matters
Built for Permanent Installation
Unlike thin or temporary plastic sheeting, VaporBlock® 20 Plus is intended for long-term, permanent installation, supporting durable, inspection-ready results in residential and light commercial construction.
Inspector FAQs: Radon & Code-Aware Questions
What is the best vapor barrier for radon mitigation?
The best vapor barrier for radon mitigation is a thick, low-permeability barrier that can be fully sealed at seams and penetrations. VaporBlock® 20 Plus is designed for under-slab and crawl space applications where durability and radon resistance are required.
Does a vapor barrier really stop radon gas?
A vapor barrier can significantly reduce radon gas migration when properly installed and sealed as part of a complete radon mitigation system. Creating a continuous barrier beneath the slab or crawl space helps limit soil gas entry points.
How thick does a vapor barrier need to be for radon?
For radon mitigation, vapor barriers in the 10-mil to 20-mil range are commonly used to improve durability and reduce the likelihood of punctures. Thicker, reinforced materials offer added protection in demanding conditions.
Is a 20 mil vapor barrier thick enough for radon protection?
Yes. A 20-mil reinforced vapor barrier is widely used in radon-resistant construction due to its low permeability and ability to maintain integrity over time when properly installed.
What vapor barrier should be used under a concrete slab?
Under a concrete slab, a vapor barrier should be durable, low-permeability, and capable of maintaining continuity during the concrete pour. VaporBlock® 20 Plus is commonly used where both moisture and radon control are priorities.
📖 Read about ASTM E-1745 and Why It Matters
Contractor FAQs: Installation & Jobsite Reality
What’s the difference between a 10 mil and 20 mil vapor barrier?
The primary difference is durability. A 20-mil vapor barrier offers greater resistance to tearing, punctures, and jobsite damage, making it better suited for gravel substrates, foot traffic, and permanent installations.
📖 Discover 20-Mil Vapor Barrier Tips
Can a vapor barrier be installed over gravel?
Yes, but thicker, reinforced materials are strongly recommended. VaporBlock® 20 Plus is designed to perform over gravel and uneven substrates, where thinner vapor barriers are more likely to fail during installation.
How do you ensure proper coverage in a crawl space?
Proper crawl space coverage requires accounting for overlaps, piers, seams, and material waste. Failing to plan for these areas can result in shortages and compromised performance.
📖 Read more about How Much Vapor Barrier Do I Need for My Crawl Space?
How long does a 20 mil vapor barrier last?
A properly installed 20-mil vapor barrier is designed for long-term, permanent installation. Reinforced materials like VaporBlock® 20 Plus can maintain performance for many years under normal conditions. However, replacement or repair may be required if the barrier is compromised by environmental changes, physical damage, or improper installation.
Common Reasons a Vapor Barrier May Need Replacement
| Reason | Explanation |
|---|---|
| Physical Damage or Punctures | Tears caused by foot traffic, stored materials, pests, or sharp gravel can compromise barrier continuity over time. |
| Improper Installation or Incomplete Sealing | Unsealed seams, penetrations, or terminations can allow moisture or soil gases to bypass the barrier, reducing effectiveness. |
| Foundation Modifications or Renovations | Structural repairs, plumbing changes, or new utility penetrations may require sections of the vapor barrier to be removed and reinstalled. |
| Extended Exposure to Standing Water or Flooding | Prolonged water exposure can stress seams and fasteners, potentially leading to failure in localized areas. |
| Degradation from Jobsite Abuse or Post-Install Activity | Crawl spaces used for storage, frequent service access, or ongoing trade work can increase the likelihood of damage over time. |
| Pest or Animal Intrusion | Burrowing animals or rodents can puncture or displace vapor barriers, especially in crawl space environments. |
| Substrate Movement or Settlement | Soil shifting or settling beneath the barrier may cause stress at seams, overlaps, or penetrations. |
💡 Inspect annually. Even the most durable vapor barrier can be compromised over time by pests, settlement, or trade activity. An annual visual inspection of seams, penetrations, and wall terminations helps catch issues early — before moisture or radon problems develop.
Color
Size
Thickness
Specification
Vapor Class
Product Data Sheets
Applications
- Crawl Space Vapor Barriers
- Gas Mitigation Vapor Barriers
- Radon Mitigation Vapor Barriers
- Underslab Vapor Barriers
Brochures & Catalogs
