Best Mil Thickness for Vinyl Flooring: Top Underlayments and Moisture Barriers
Vinyl flooring projects benefit from a proper moisture barrier and underlayment to protect the substrate and optimize comfort. The right mil thickness helps prevent moisture migration, minimize sound, and support long-term floor performance. This guide reviews five products that exemplify popular mil choices for vinyl flooring: Roberts moisture barricade underlayment films in 6 mil thickness; the Quiet Walk acoustical underlayment with vapor barrier; Roberts 70-198 silicone moisture barrier; Roberts 70-116; and RestorePontoon 80 mil vinyl flooring for comparison on mil variety. Each option serves different installation types and budgets, from simple vapor barriers to robust multi-purpose underlayment.
| Product | Mil / Thickness | Coverage | Primary Use |
|---|---|---|---|
| Roberts 70-115 Moisture Barricade Underlayment Film | 6 mil | 120 sq ft | Vapor barrier underlayment for vinyl, laminate, SPC, engineered wood |
| Quiet Walk 360 Sq Ft Acoustical Underlayment | 4 mm+ thickness (underlayment) | 360 sq ft | Acoustical underlayment with vapor barrier for LVP/LVT/SPC |
| Roberts 70-116 Moisture Barricade Film | 6 mil | 300 sq ft | Vapor barrier for vinyl, laminate, SPC, engineered wood |
| Roberts 70-198 Silicone Moisture Barrier Underlayment | 6 mil (silicone barrier) | 200 sq ft | Moisture barrier underlayment for solid/engineered wood and LVP |
| RestorePontoon 80 Mil Vinyl Flooring | 80 mil | Approximately 212 sq ft | Vinyl flooring with high wear resistance; top layer option |
Roberts 70-115 Moisture Barricade Underlayment
Roberts 70-115 Moisture Barricade Underlayment Film is a 6 mil polyethylene sheet designed as a vapor barrier for vinyl, laminate, SPC, and engineered wood flooring installations. The durable 6 mil thickness helps resist moisture creep from concrete slabs and crawl spaces, aligning with NWFA requirements. The film rolls out to cover a 10 by 12 foot area per roll, providing a straightforward, low-profile layer that sits beneath the top flooring system. This underlayment supports floating and glue-down methods while helping to minimize sound transmission and protect subfloors from moisture damage. The product exceeds NWFA requirements.
Because it’s a film-based barrier, installation involves unrolling and sealing seams with tape to prevent gaps. The 10′ x 12′ coverage per roll reduces waste on smaller projects. It’s particularly suitable in basements and other moisture-prone spaces where concrete subfloors lie beneath. For vinyl flooring setups, installing this barrier beneath the underlayment or directly under the planks is a common practice to reduce moisture migration and maintain floor stability over time.
Quiet Walk Acoustical Underlayment
Quiet Walk 360 Sq Ft Acoustical Underlayment with Vapor Barrier is designed for floating, glue-down and nail-down installations of Luxury Vinyl Flooring (LVP, LVT, SPC) and for engineered wood and laminate. It has a 4mm+ thickness and includes a vapor barrier to block moisture transmission. The underlayment uses recycled fibers that absorb impact sound and reduce noise transfer, improving living spaces. It is suitable for floating or adhesive installations and helps create a quieter floor with more comfortable footing.
The dense fiber structure provides compression resistance, maintaining stability under heavy furniture and foot traffic. It supports long-term durability and helps protect against early wear in busy rooms. Installation is straightforward with standard tools, and seams can be taped for a continuous barrier. In homes with upstairs living areas or open-plan layouts, the sound-damping benefits can be noticeable, enhancing room-to-room comfort without adding bulk.
Roberts 70-116 Moisture Barricade Film
Roberts 70-116 Moisture Barricade is a 6 mil polyethylene film designed as a vapor barrier for vinyl, laminate, SPC and engineered wood floors. It offers a 6 mil thickness and 300 sq ft total coverage, making it suitable for mid-to-large projects. The film is ideal for use with laminate flooring with pre-attached underlayment and with floating resilient products over concrete slabs, since it reduces moisture migration. This barrier helps NWFA-level moisture protection across various sub-floors, including concrete, and unrolls quickly for efficient installation. Seams should be sealed to prevent moisture migration.
The film is thin yet durable, providing essential moisture protection without adding substantial height. It is well-suited for projects where a simple, reliable vapor barrier is required under a floating or glued-down system. For larger spaces, multiple rolls can be joined with tape to create a continuous barrier, ensuring consistent moisture control throughout the installation.
Roberts 70-198 Silicone Moisture Barrier Underlayment
Roberts 70-198 Silicone Moisture Barrier Underlayment is designed for solid and engineered wood floors and LVP, offering a 6 mil film with a silicone moisture barrier layer. It reduces vapor flow without trapping moisture and has lab tested and approved use with radiant heat systems. The product serves staple or nail-down installations and provides a stable, low-permeability barrier under a variety of flooring types.
Because of its silicone formulation, it can adapt to different substrate conditions and helps minimize squeaks and bounce. Use with appropriate subfloor preparation and recommended adhesives or fasteners. This underlayment serves as a versatile option for projects where radiant heat or mixed-floor materials are present, delivering reliable moisture control without compromising subfloor integrity.
RestorePontoon 80 Mil Vinyl Flooring
RestorePontoon 80 Mil Vinyl Flooring (Stone Gray) is an 80 mil vinyl flooring option, sized 8’6″ x 25′. The thicker mil thickness provides enhanced wear resistance and durability for high-traffic areas. The embossed slip-resistant surface improves safety, and the product exceeds Department of Commerce requirements. While not an underlayment, the 80 mil thickness represents a durable top surface choice for busy households and demanding spaces where long wear is a priority.
This vinyl flooring is designed for direct installation on suitable substrates using standard adhesive methods or per the manufacturer’s recommendations. When choosing vinyl thickness, consider climate, substrate flatness, and expansion gaps to ensure a proper fit and longevity. The extra thickness can influence installation and performance in areas subject to heavy use or moisture exposure, making it a viable option for comparison with barrier and underlayment products.
Buying Guide: Key Purchase Considerations
Choosing the right mil thickness for vinyl flooring involves balancing moisture control, acoustic performance, installation method, and subfloor conditions. Here are essential factors to consider from multiple perspectives:
- Moisture protection vs. acoustic goals: For moisture control under vinyl and engineered floors, consider 6 mil barrier films (Roberts 70-115, 70-116, 70-198) and pair with an acoustical underlayment like Quiet Walk if sound reduction is a priority.
- Installation method and substrate: Floating, glue-down, and nail-down installations have different requirements. Underlayment and vapor barriers must align with the chosen method and with concrete or wood subfloors, including radiant heat compatibility (70-198 supports radiant systems).
- Mil thickness implications: A 6 mil film provides strong moisture protection for many subfloors, while higher mils (80 mil) in vinyl flooring itself offers greater wear resistance for busy areas. Balance protection with budget and installation complexity.
- Coverage and waste planning: Check roll size and total coverage to estimate material needs. Some products come in ~120–360 sq ft per roll, affecting planning for larger rooms or multiple rooms.
- Subfloor compatibility: Polyethylene barrier films are versatile over concrete, gypsum, or wood subfloors, but ensure compatibility with radiant heat if used. Silicone barriers add a different protective profile for complex installations.
- Maintenance and longevity: Acoustic underlayments improve comfort and reduce footstep noise; moisture barriers protect against future subfloor damage. Consider the environment, traffic, and room usage when selecting products.
- Installation tips: Ensure clean, dry subfloors; seal seams with appropriate tape; avoid overlaps that trap moisture; follow manufacturer guidelines for thickness and seam treatment to maximize performance.
In summary, the best mil choice depends on your project specifics: use 6 mil moisture barriers for general vinyl and laminate installations; opt for heavier mil vinyl like 80 mil when durability is paramount; pair barrier films with acoustical underlayment where noise reduction matters; and consider radiant heat compatibility for long-term performance. The five products reviewed offer a spectrum of options to fit typical residential vinyl flooring projects.