Winterizing with Clear PVC Tarps

Clear PVC tarps are one of the simplest ways to winterize a patio or pergola. They act like temporary transparent walls that block wind, rain, and snow while keeping the outdoor view. But successful winterizing depends on using the right cold rating, mounting anchors correctly, and choosing panel sizes that don't fail under winter stress.

1. Understand Cold-Crack Ratings

Clear PVC becomes stiffer as temperatures drop. That's why PVC tarps are rated by their "cold-crack" threshold — the temperature at which the material can crack under stress.

• -10°F / -23°C rating: Good for most mild to moderate winters.
• -20°F / -29°C rating: Better for northern U.S. and Canadian winters.
• -40°F / -40°C rating: Extreme cold climates.

If your tarp isn't rated for your climate, it may crack when rolled, bent, or impacted by wind.

2. Size Panels Correctly (The Secret to Avoiding Cracks)

Oversized PVC panels act like giant wind sails. The larger the panel, the more force is transferred into the mounting points. Smaller sections perform better in winter:

• Panels under 8 ft wide are easier to tension and resist cracking.
• Taller than 10–12 ft drastically increases wind load.
• Break one big wall into two or three smaller PVC sections.

This is the difference between a peaceful winter enclosure and ripped grommets by January.

3. Use a Solid Mounting Strategy

Winter demands stronger mounting than summer use.

Recommended anchor points:

• Top fixed track or hooks: This carries 90% of the load.
• Side tension straps: Prevent flapping and reduce panel fatigue.
• Bottom anchors: Critical for wind. Options include bungee balls, weighted bars, or rail tracks.

The goal is to eliminate "slack zones" where wind can punch into the tarp.

4. Seal the Bottom for Wind Control

Cold drafts don't enter from the top — they enter from the bottom. If your patio gets gusty:

• Weighted bottom hem: Reduces lift.
• Ground anchors: Important in windy or elevated decks.
• Wooden base strip: Creates a tight seal and protects against snow.

This single step can make a patio feel 10–20°F warmer.

5. Expect Window-Like Warmth (But Not Full Insulation)

PVC traps heat surprisingly well, especially on sunny days. It's like adding temporary greenhouse walls. However, it will not fully insulate the space. You'll get:

• Reduced wind chill
• Significantly warmer air pockets
• Comfortable seating zones, even in winter sun
• Greater use of patio furniture year-round

But don't expect heated-room-level comfort unless you add space heaters and allow warm air to accumulate.

6. Avoid Opening and Closing in Extreme Cold

The colder the tarp, the less flexible it becomes. Opening rolled PVC panels in freezing weather can cause stress cracks along the mounting line.

Rule of thumb: Avoid rolling or folding below freezing.

7. Add Ventilation Points (Optional but Smart)

Fully sealed PVC enclosures can trap humidity. This leads to fogging, condensation, or mildew odors.

Helpful add-ons include:

• Zipper vents near the top
• Partial gaps near corners
• Roll-up sections for mild days

These small openings prevent moisture buildup while keeping wind outside.

8. When Winter Is Over: Safe Storage

Proper storage dramatically extends tarp life. Follow these steps:

• Clean with mild soap and water before storage.
• Dry completely to avoid odor or mold.
• Roll — never fold — clear PVC.
• Store away from heat sources.

Treated correctly, a quality winter-rated PVC tarp can last several seasons.

Next Step

Learn how to secure PVC panels for storms and windy conditions:
PVC Wind Behavior & Stability Guide