If you’re planning to turn a damp, musty crawl space into a dry, usable area, a crawl space encapsulation kit can simplify the process. But not all kits are created equal—and knowing what components to look for, the difference between barrier thicknesses, and how to match a kit to your space matters.
In this article we’ll present the key items inside a kit, how to compare materials (e.g., 6 mil vs 12 mil vapor barrier), how to choose tape, adhesives and other accessories, and give you a product-section example to help clarify. We’ll keep the tone simple, easy to understand, following a friendly “home improvement” style.
What a Crawl Space Encapsulation Kit Typically Includes
Encapsulation kits bundle together many of the materials you’ll need to seal the floor and walls, cover piers/vents, and finish off a crawl space. Below are common components:
- Vapor barrier rolls (to cover the ground and often walls)
- Seam tape or butyl tape (to seal overlaps and corners)
- Termination strips or attachment hardware (to secure barrier to walls/columns)
- Vent covers or vent seal kits (to close exterior vents)
- Instructions or DIY guide (some kits are labelled “DIY friendly”)
- Sometimes accessories like corner patches, adhesive, fasteners
- Occasionally optional items like a humidity monitor, sealant around piers/penetrations
For example, one kit description says: “The Crawl Space Liner Kit includes all the needed components to seal walls and floors … includes our premium 10 Mil woven liner, tape, etc.”
Another professional site lists needed materials for encapsulation: “Vapor Barriers: These are thick, polyethylene sheets (typically 8-20 mil) … Insulation … Sealing Components: High-quality tapes and adhesives.”
Key Features to Compare When Choosing a Kit
Vapor Barrier Thickness: 6 mil vs 12 mil (or more)
One of the first things to compare is the thickness of the plastic liner included. A “mil” is a thousandth of an inch. Thicker means more durability, less risk of puncture or tear, and longer lifespan.
- A 6 mil sheet is on the thin side—it may work in very mild, easy conditions, but is prone to damage.
- A 10 to 12 mil sheet gives better durability and is often recommended in serious crawl space work. For example one guide recommends a “minimum of 12-mil” for long term durability.
- Premium kits may offer 15-20 mil or even reinforced woven liners for high-moisture or commercial use.
When picking a kit, check what thickness is provided, whether it’s single layer or reinforced, and ask: is the ground smooth/rocky? Are there sharp piers/metal posts? Harder conditions demand thicker material.
Tape, Seams & Termination Hardware
A liner is only as good as its seals. Good kits include high-quality seam tape or butyl tape, termination strips (to fix barrier to concrete walls or piers), and corner patches. Poor kits may skimp here. One site notes: “Our floor liners are joined with proprietary seam tape to ensure continuous reliable vapor barrier.”
Ask: Does the kit include tape? How wide is it? Does it cover corners? Are attachment strips included for walls/piers? Do I need additional fasteners?
Vent Covers / Exterior Vent Seals
Encapsulation often requires sealing or covering existing crawl space vents to prevent humid outside air from entering. A kit may include vent covers or vent closing kits. One professional breakdown of encapsulation system components lists “vent covers” as part of the system.
Make sure the kit either includes these or clearly lists that vent sealing is your responsibility. If you live in a humid climate, proper vent sealing is critical.
Coverage Area / Size of Kit
Kits often specify a coverage area (e.g., “for up to 500 sq ft crawl space”). For instance, one kit states: “…sized up to approximately 500 square feet.”
Make sure the kit you pick matches (or exceeds) your crawl space’s floor area (and ideally wall area) so you don’t have to buy extra rolls or mismatched accessories.
Additional Features / Upgrades
More advanced kits might include:
- Reinforced liners (woven or high-tensile)
- Built-in humidity monitors or provisions for dehumidifier
- Adhesive sealants for piers and penetrations
-
Warranty or manufacturer guarantee (e.g., 25 years)
These extras raise the cost but also raise quality and longevity.
SuperBarrier Crawl Space Encapsulation Kit – DIY 500 sq ft Version
Designed for homeowners tackling their own job. Includes 500 sq ft of 12 mil reinforced liner, seam tape roll, 20 termination strips, vent-covers, DIY instruction manual.
Advantages:
- 12 mil offers good durability for most homes
- Bundle gives almost everything you need (minus drainage/fixing major water issues)
-
DIY friendly (instructions included)
Disadvantages: - Only for up to 500 sq ft – if your crawl space is larger you’ll need extra material
- Does not include a dehumidifier or sump pump—those are additional costs
- DIY installation still requires effort/time and careful work around walls/piers
How to Choose the Right Kit for Your Situation
- Measure your space. Get floor area, wall length, height & piers. This helps select correct coverage.
- Assess condition of crawl space. If you have standing water, leaks, large cracks or structural issues—then you may need more than a kit (drainage, sump pump, repair) and the kit alone might not suffice. One guide says: “A properly encapsulated crawl space addresses moisture, standing water, mold… but plastic alone is not enough.”
- Select liner thickness based on conditions. If mild/dry region and easy access – 10-12 mil may be fine. If humid/wet region or rough ground/metal posts/installation risk – go for heavier (15-20 mil or woven).
- Check included accessories. Make sure kit includes tape, termination hardware, vent covers or at least clear specification of what you need to buy extra.
- Consider installation effort. DIY vs professional. A kit saves cost but you’ll need to work safely in the crawl space, tape seams perfectly, secure around piers, etc.
- Evaluate upgrade potential. If you later want to add a dehumidifier, drainage system or insulation, pick a kit that leaves room for these. Some guides emphasize that after barrier/insulation you may still need a dehumidifier.
- Budget vs quality. Cheaper kits may look tempting but may include thin liner, minimal tape or no vent covers—leading to premature failure. Good investment for long term.
Frequently Asked Questions
What thickness vapor barrier do I need for a crawl space kit?
It depends on conditions. Many professionals recommend at least 12 mil for durability and puncture resistance. Kits with thinner 6 mil are less robust and more prone to damage.
Does a kit replace the need for a dehumidifier?
Not always. A kit will help block ground moisture and outside humidity, but if your region is humid, your crawl space has remaining moisture sources (soil vapour, leaks) or you want precise humidity control, a dedicated dehumidifier may still be advised. One guide states that encapsulation involves “vapor barrier, insulation, dehumidifier” for full protection.
Should I buy extra tape/seam material?
Yes—especially if your space is irregular, has many piers, posts, corners or rough surfaces. Seam failures often happen at corners/penetrations, so budget extra tape/patch material even if kit includes some.
Are vent covers included in all kits?
Not always. Many kits include vent covers but some leave vent sealing to the homeowner/contractor. Since exterior air venting can undermine encapsulation, check whether your kit covers it or you need to purchase separate vent-cover kits.
Conclusion
A crawl space encapsulation kit can be a great way to bundle the materials you need to transform a damp, uncontrolled crawl space into a dry, healthier zone. The key is to pick the right kit for your conditions—size of space, region’s humidity, severity of moisture issues, your DIY skill level, whether you plan to add a dehumidifier later.
Focus on liner thickness (aim for 10-12 mil or more if needed), quality of tape/seams, vent covers and kit coverage area. If you pair the right materials with good installation (and address underlying water/soil issues), you’ll set up your crawl space for long-term success.
