Clear PVC tarps behave differently from fabric: they're rigid, sensitive to cold, and rely heavily on
proper tension. Most issues come from installation details rather than the material itself.
Below are the most frequent problems and the simplest ways to solve them.
1. Fogging or Cloudiness
Fogging happens when moisture gets trapped between the tarp and surrounding air.
Causes:
- Temperature difference between inside and outside
- High humidity inside patio or gazebo
- Lack of small airflow gaps
- Direct contact with cold windows or metal
Fixes:
- Add a small airflow gap (½ inch at top or bottom)
- Use a dehumidifier or outdoor-rated heater
- Avoid installing panels in cold weather — PVC traps moisture during handling
- Clean with warm water + mild soap to restore clarity
Prevention:
Install PVC on a dry day and leave panels slightly ventilated during large temperature swings.
2. Yellowing Over Time
UV exposure gradually affects all clear plastics.
Causes:
- Strong direct sunlight for long periods
- Chemical cleaners (ammonia, alcohol, harsh detergents)
- Excessive heat trapped behind the panels
Fixes:
- Move panels to shaded sides during summer if possible
- Clean only with mild soap and water
- Use UV-protection spray rated for PVC (applied sparingly)
Yellowing is mostly a long-term aging effect — proper care slows it significantly.
3. Scratches & Surface Marks
Clear PVC scratches easily, especially when rolled or handled in cold weather.
Common causes:
- Cleaning with paper towels or abrasive sponges
- Dragging the panel across the ground
- Rolling up in temperatures under 45°F
Fixes:
- Use microfiber cloths only
- Warm the material slightly before handling
- Apply plastic polish designed for vinyl windows
Minor scratches won't affect strength — only clarity.
4. Flapping or Noise in Wind
Flapping means the panel isn't fully tensioned or wind is entering around the edges.
Fixes:
- Add bottom tension using weights or a bottom rail
- Anchor sides every 12–18 inches
- Switch from bungees to fixed hooks on the top edge
- Break large sides into smaller panels for stability
For deeper wind science, see:
PVC Wind Behavior Guide
5. "Ballooning" (Tarp Puffs Out in Gusts)
This happens when wind gets behind the panel. It dramatically increases stress.
Fixes:
- Seal or tighten side edges to prevent wind entry
- Install a bottom anchor so gusts can't lift the panel
- Reduce panel width if larger than 8–10 ft
Ballooning is the most dangerous PVC behavior for long-term durability.
6. Grommets Pulling Out or Tearing
Grommet failure almost always comes from wind load or uneven tension.
Fixes:
- Distribute load with more anchor points
- Use bungees instead of rigid hooks on sides/bottom
- Replace missing grommets with reinforced patch kits
- Add mid-panel straps if force is concentrated in one area
7. Poor Fit or Gaps
Gaps create drafts, allow rain entry, and increase noise.
Fixes:
- Switch to face-mounting for tighter coverage
- Add side tracks to eliminate spacing
- Re-measure the opening — most issues trace back to wrong sizing
For measuring instructions, see:
PVC Measuring Guide
8. Cold Cracking or Stiffness
PVC becomes brittle below its cold-crack rating.
Fixes:
- Use PVC rated for 0°F or lower if winters are severe
- Do not roll or fold PVC below 45°F
- Warm the panel indoors before installation
Cold damage is permanent — prevention is the key.
9. Water Leaks at the Top or Sides
Usually caused by unsealed mounting points or incorrect slope.
Fixes:
- Add a drip edge or flashing above the top mount
- Tighten all top anchors evenly
- Ensure the tarp overlaps or meets the beam fully
10. Excessive Wrinkling or Waves
Minor wrinkles fade over time, but severe waves indicate slack or uneven tension.
Fixes:
- Re-tension bottom anchors
- Tighten side grommets evenly
- Add a mid-panel tension strap on windy walls
Summary
Most PVC tarp issues—fogging, flapping, ballooning, noise, and tearing—come from installation details.
Tight, even tension and correct panel sizing solve nearly all problems.
Back to the hub:
Clear PVC Tarps & Outdoor Enclosures