Why Choose the ProSaunas 48 ” × 325 ‘ Vapor Barrier?
- True Radiant Performance – Pure 99-% aluminum reflects radiant heat; no laminated plastic films that degrade above 180 °F.
- One Roll, Fewer Seams – A 48-inch width means 20 % fewer horizontal seams than 36-inch rolls, saving labor and reducing vapor-leak points.
- Built for Sauna Temperatures – Rated for continuous service above 230 °F and intermittent spikes up to 400 °F, so it won’t sag, outgas, or delaminate.
- Dual-Purpose Efficiency – Combines Class I vapor retardancy (≤ 0.1 perm) with 97 % emissivity, slashing heat loss while locking out moisture.
- Versatile Beyond the Sauna – Use it behind steam showers, in basements, crawl spaces, attics, metal buildings, or anywhere condensation threatens comfort and structure.
| Feature | Benefit for You |
|---|---|
| Pure-Aluminum Foil (0.003 in thickness) | Maximum heat reflection and zero plastic odor at sauna temps |
| Heavy-Duty Kraft Backing | Adds tear strength without compromising reflectivity |
| 1,300 sq ft Coverage | One roll is enough for a typical 6 × 8 ft sauna—including ceiling—with material to spare |
| Temperature Rating: -40 °F to 400 °F | Peace of mind from Midwest winters to daily 190 °F sauna sessions |
| Class I Vapor Retarder | Blocks humid vapor, limiting mold, rot, and insulation failure |
| Mold & Mildew Resistant | Inorganic aluminum surface won’t harbor bio-growth |
| Made for Air-Gap Install | ⅞ ” furring strips or foil-faced PIR create the critical gap for true radiant performance |
Recommended Wall & Ceiling Assembly
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Exterior – Siding or cladding
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Rain Screen / Air Gap – ⅜ – ¾ in
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Insulation – Mineral wool or foil-faced PIR (optional for interior walls)
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Stud Cavity – 2 × 4 or 2 × 6 framing
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ProSaunas Vapor Barrier Foil – seams taped with matching foil tape
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Service Air Gap – ¾ in furring strips or foil-faced rigid insulation
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Interior Finish – Tongue-and-groove cedar, spruce, basswood, or thermo-aspen
Pro Tip: Keep electrical boxes outside the foil layer or use vapor-sealed boxes to maintain the barrier.
Installation Essentials
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Tools Required: Sharp utility knife, stapler, 2-in foil tape, ¾-in furring strips.
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Overlap & Tape: Overlap seams 2 in and tape full length; tape every staple row to maintain vapor seal.
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Maintain Air Gap: Run vertical furring strips every 16 in OC before installing interior cladding.
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Avoid Bubble Foils: Plastic-core foils can melt and trap moisture—use pure aluminum for true sauna durability.
Coverage Calculator
| Sauna Size (Interior) | Walls + Ceiling Surface Area | Rolls Needed |
|---|---|---|
| 4 ft × 6 ft × 7 ft h | ~240 sq ft | 1 roll (18 % left over) |
| 6 ft × 8 ft × 7 ft h | ~350 sq ft | 1 roll (73 % left over) |
| 8 ft × 10 ft × 7 ft h | ~500 sq ft | 1 roll (62 % left over) |
(Left-over material is ideal for door jambs, benches, or future repairs.)
Frequently Asked Questions
Q: Can I install this foil tight against the interior wood?
A: It will still stop vapor, but you’ll lose the radiant-heat benefit. Always create a ¾ in air gap for maximum performance.
Q: Is this the same as the foil bubble wrap at my local hardware store?
A: No. Bubble wraps use plastic cores that can sag, melt, or off-gas in a 190 °F sauna. ProSaunas foil is a solid, pure-aluminum sheet rated for continuous high heat.
Q: How do I tape seams?
A: Use 2-in or wider HVAC-grade foil tape. Overlap foil 2 in, press firmly, and smooth bubbles to maintain a complete vapor seal.
Q: Do I need a separate vapor retarder?
A: No—the ProSaunas foil is a Class I vapor retarder and radiant barrier in one, simplifying your wall build.
Who It’s For
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DIY Sauna Builders looking for professional-grade results without pro-level headaches.
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Contractors & Remodelers who want to back up their craftsmanship with materials that protect the structure and their reputation.
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Energy-Savvy Homeowners seeking lower heating costs and mold-free walls in basements or crawl spaces.
The Sauna Marketplace Promise
At SaunaMarketplace.com we curate products we’d use in our own builds—no gimmicks, no shortcuts. Our U.S.-based support team is here to answer installation questions and help you get the most out of every roll.
Add to Cart today and feel the difference a true radiant barrier makes in your next sauna session.
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