Plastic Sheeting (HDPE) Buying Guide: Choosing 30–100 Mil for Your Project
Longview Supply plastic sheeting is smooth, commercial-grade HDPE (High Density Polyethylene) designed for demanding indoor and outdoor use. This guide helps you pick the right thickness (“mil”), estimate quantities, and install/seam panels cleanly—whether you’re protecting a surface, creating a barrier, or building a durable liner.
Quick pick: what thickness should I start with?
- 30–40 mil: flexible barrier for lighter duty protection and general use.
- 50–60 mil: a strong “workhorse” range—great puncture resistance while still workable by hand.
- 80 mil: reinforced, very durable for high-abuse areas where toughness matters most.
- 100 mil: maximum toughness and puncture resistance when durability is priority #1.
Mil thickness chart (what it means in plain English)
“Mil” is a thickness unit: 1 mil = 0.001 inch. The thicker the sheet, the more it resists punctures and abrasion. Thicker sheets can still be workable, but they take more effort to cut, shape, and seam.
| Product | Thickness | Best for | Practical example |
|---|---|---|---|
| 30 mil | 30 mil = 0.030" (≈ 1/32") | Flexible barrier and general protection where the sheet won’t be heavily abused. | Protecting a wall or partitioning a light-duty area where you still want a cleanable waterproof surface. |
| 40 mil | 40 mil = 0.040" (≈ 3/64") | More rugged while still flexible; a solid upgrade when you expect bumps and wear. | Barrier paneling in a work area where carts, equipment, or routine contact are expected. |
| 50 mil | 50 mil = 0.050" (1/20") | High puncture resistance with good workability; versatile for above-ground moisture control or buried barriers. | Installing a durable moisture barrier where you’ll be fastening, trimming, and washing periodically. |
| 60 mil | 60 mil = 0.060" (≈ 1/16") | A strong “go-to” thickness: durable + flexible, great puncture resistance. | Creating a long-lasting protective wall/floor panel that can be cleaned often and still hold up. |
| 80 mil | 80 mil = 0.080" (≈ 5/64") | Reinforced, extremely durable; ideal when impact/abrasion risk is high. | High-abuse protection barrier where sharp edges or heavy contact could tear thinner material. |
| 100 mil | 100 mil = 0.100" (≈ 3/32") | Maximum puncture resistance; durability is the priority, flexibility is secondary (but still workable). | Critical protection barrier where failures are costly—choose the toughest option. |
Not sure? Start with 60 mil when you want a “do-most-things” thickness that balances strength and workability. Go thicker (80–100) for higher abuse; go thinner (30–40) for lighter duty and easier handling.
Products in the Plastic Sheeting collection
These are the core thickness options offered in this collection. Click into a product to choose your roll width/length and see available variants.
30 Mil Plastic Sheeting
Flexible HDPE barrier for general use with a smooth, waterproof surface.
40 Mil Plastic Sheeting
Rugged while still flexible—great when you expect more wear and contact.
50 Mil Plastic Sheeting
High puncture resistance + flexibility for a wide range of barrier needs.
60 Mil Plastic Sheeting
Durable “workhorse” thickness—strong, puncture resistant, and still workable.
80 Mil Plastic Sheeting
Reinforced and extremely durable—built for higher abuse and tougher environments.
100 Mil Plastic Sheeting
Maximum toughness and puncture resistance—when durability matters most.
Want help choosing? Call (800) 621-5381 or request a written quote above—especially if you’re matching an existing thickness or need volume pricing.
How to estimate the roll size you need
Most projects come down to two decisions: roll width (how tall/wide your coverage needs to be) and total linear feet (how long the run is). Here’s a simple workflow.
1Measure your coverage area
- Wall / partition: height needed × total run length
- Floor protection: width needed × total run length (or multiple strips)
- Barrier ring: perimeter length + overlap allowance
2Add seam/overlap allowance
- Add 6–12 inches per seam for overlap (buried) or plan tight seams (exposed).
- Add extra length for corners and trimming.
3Pick thickness based on “abuse level”
- Low abuse: 30–40 mil
- Medium: 50–60 mil
- High: 80–100 mil
4Order a sample if you’re unsure
If you’re deciding between two thicknesses, a sample helps you feel flexibility and stiffness before ordering a full roll.
Real-world example: durable barrier panel run
You need a 36" tall barrier across a 70 ft run. You’ll use two seams and want extra material at each end.
- Base length: 70 ft
- Add 2 seams × 1 ft allowance = +2 ft
- Add end trimming/wrap: +3 ft
- Total target: 75 ft
If your barrier will be cleaned often or may get bumped by equipment, step up to 60 mil for better puncture resistance while staying workable.
Seaming and connecting sheets (two practical methods)
When your coverage requires multiple pieces, choose an overlap seam (best for buried applications) or an end-to-end seam (best for exposed installations). Using the right tape makes the seam cleaner and more reliable.
Overlap method (best underground)
- Overlap the sheets to create a broad sealing area.
- For moisture-resistant overlap seams, use HDPE Barrier Tape (Moisture Resistant).
- Press firmly along the seam line to ensure full contact and reduce channeling.
- Avoid overlap ridges in exposed, high-traffic areas—edges can catch and pull apart over time.
End-to-end method (best exposed)
- Butt the edges together (no overlap ridge).
- For a clean exposed seam, use HDPE Seam Tape (Single Sided) to bridge the joint.
- Work from one end to the other to keep the seam straight and prevent wrinkles.
- This method helps reduce snag points on walls/floors and keeps the surface flatter.
Installation checklist (fast, clean results)
1Prep the surface
- Remove sharp debris (rocks, metal edges, exposed fasteners).
- On soil installs, compact and smooth to reduce point loads.
2Cut and dry-fit
- Lay the sheet in place and mark cut lines before trimming.
- Keep edges square where seams will be taped.
3Seam (if needed)
- Buried overlap: overlap + moisture-resistant tape for added water resistance.
- Exposed end-to-end: butt seam + single-sided seam tape for a flatter finish.
4Anchor or protect edges
- Trim flush and protect leading edges from catching.
- For buried installs, backfill evenly to avoid shifting the seam.
Pro tip: For exposed, high-contact areas, upgrading thickness (60 → 80 mil) is often the simplest path to longer service life.
Shipping and ordering tips
- Free standard shipping is commonly available on plastic sheeting orders; expedited shipping may require a higher order total.
- If timing is critical, call to confirm what’s shipping fastest for your thickness and roll size.
- Need to match an existing install? Ordering a sample first helps avoid rework.
Need help quickly? Call (800) 621-5381 with your thickness + roll size and we’ll help you pick the best option.
FAQ
What does “mil” mean, and why does it matter?
“Mil” is a thickness measurement: 1 mil = 0.001 inch. Thicker sheets generally resist punctures and abrasion better, while thinner sheets are easier to handle.
Which thickness is the best all-around choice?
If you want a balance of durability and workability, 60 mil is a strong starting point. Go thinner for lighter duty; thicker for higher abuse.
How should I seam two sheets together?
For buried installs, overlap seams are typically preferred because the larger contact area helps with water resistance. For exposed installs, end-to-end seams reduce snag points and look cleaner—then bridge the joint with seam tape.
Can this be used outdoors in sunlight?
HDPE plastic sheeting is commonly used outdoors. For exposed, high-traffic areas, choosing a thicker mil helps improve durability.
