A tonneau cover is an excellent way to protect your truck bed and any cargo inside from weather and UV damage. But how well do tonneau covers actually block those harmful UV rays from reaching your belongings? Let’s take a closer look at how tonneau covers work and which types offer the best UV protection.
What Are The Main Causes Of UV Damage To Cargo?
UV radiation from sunlight can damage and degrade many materials over time. Here are some of the main concerns:
Fading And Discoloration
UV rays can cause dyes and pigments to break down and fade. This is especially problematic for fabrics, clothing, upholstery, and other colored materials. Even plastic and rubber can experience fading and discoloration after prolonged UV exposure.
Degradation Of Organic Materials
Materials such as wood, paper, cotton, wool and food are vulnerable to UV damage. The radiation dries out natural fibers and causes brittleness. It also accelerates food spoilage.
Damage To Electronics
Certain components inside electronic devices are sensitive to UV radiation. Displays, circuits and plastic casings can all be affected over time. The lifespan of electronics left in the sun is reduced.
Accelerated Aging Of Materials
From gaskets and hoses to tires and tonneau covers themselves, UV rays cause premature breakdown of polymers and rubbers. Cracking, leaking and tearing can occur faster than normal.
What Types Of Tonneau Covers Offer The Best UV Protection?
Tonneau covers use different materials and designs to block sunlight. The level of UV protection depends on the type:
Do Vinyl Tonneau Covers Block UV Rays?
Vinyl is one of the most common tonneau cover materials. It is relatively affordable and easy to clean. But how effective is it at blocking UV rays?
The Short Answer
Vinyl tonneau covers provide good UV protection that is superior to having no cover at all. However, vinyl allows more UV transmission than most other tonneau materials.
UV Resistance Of Vinyl
Vinyl has moderate UV-blocking abilities. It is treated with UV inhibitors during manufacturing to help absorb and reflect UV rays. This protects the vinyl itself from sun damage.
Performance Over Time
The UV inhibitors in vinyl tonneau covers gradually deplete over years of sun exposure. This causes the material to become more transparent and lose some of its UV resistance. Performance degrades slowly but steadily.
Protecting Cargo From Fading
Vinyl tonneaus significantly cut down on UV rays reaching your cargo compared to an uncovered bed. However, they allow more light through than canvas, aluminum or fiberglass covers. Fading is still possible over extended periods.
Some vinyl covers are backed with a layer of aluminum for better heat and UV reflectivity. There are also dual-layer vinyl covers with a foam core for enhanced protection.
How Effective Are Aluminum Tonneau Covers Against UV Rays?
With their ultra-durable metal construction, aluminum tonneau covers provide unmatched UV protection:
Total UV Blockage
Solid aluminum shields cargo from virtually 100% of UV rays, unlike permeable fabrics or vinyls. The metals reflect or absorb UV radiation.
Strength And Rigidity
Aluminum’s hardness and rigidity prevents sagging, punctures and tears that could allow sunlight in. The metal withstands years of UV exposure without degrading.
On the downside, aluminum tonneaus are the heaviest type. Payload capacity is reduced unless you drive a heavy-duty pickup. The material also conducts heat into the bed.
Costs More Upfront
Quality aluminum covers are more expensive than vinyl initially. But their exceptional durability offsets the higher costs over time.
Best For Sensitive Cargo
Overall, aluminum is the ultimate UV-blocking material for tonneau covers. It offers fail-safe sun protection for fragile or valuable cargo.
How Do Canvas Tonneau Covers Compare For Blocking UV Rays?
Canvas tonneau covers blend durability with affordability. But how good are they at shielding your cargo from sun damage?
UV Resistance Varies
Canvas’ UV resistance depends on thickness and whether it is vinyl-coated. Thin pure cotton canvas fades faster than thick marine-grade vinyl-coated canvas in the sun.
Improved Performance When New
Most new canvas tonneaus are treated with UV inhibitors. These help absorb UV rays and prevent premature fading and wear. Effectiveness gradually decreases over time.
Potential For Shrinkage
Untreated canvas left in the sun can shrink up to 3% of its size as fibers dry out. Vinyl-lamination helps minimize this. Shrinkage leads to poor fit and gaps.
Longevity With Proper Care
Regular cleaning and conditioning preserves canvas’ UV resistance. Parking in shade extends its life. But deteriorated canvas eventually needs replacing.
Better UV Protection Than Vinyl
Although canvas degrades faster than aluminum and fiberglass, it blocks more UV than vinyl covers when new. Especially thicker marine-grade canvas.
Can Fiberglass Tonneau Covers Provide Total UV Protection?
Fiberglass tonneau covers deliver excellent UV resistance thanks to these properties:
The woven glass fibers are encased in hardened plastic resin. This creates an impenetrable barrier that reflects virtually 100% of UV rays.
Strength And Shape Retention
Fiberglass retains its rigid molded shape permanently. It cannot warp, sag or form gaps over time that would let in sunlight.
Unlike canvas, fiberglass’ UV resistance never degrades. Its glass/resin composition is impervious to sun damage. Fiberglass tonneaus last decades.
Added Protection For The Bed
The thick fiberglass shields the bed itself from UV rays, preventing liner and paint deterioration. Aluminum conducts heat that can still damage the bed.
Fiberglass is one of the most expensive tonneau materials. The exotic glass/resin construction and meticulous hand-crafting require added labor costs.
An Ideal Choice Overall
If you seek uncompromising UV protection for fragile, valuable cargo, fiberglass tonneaus are a smart long-term investment. Their UV-blocking abilities rival aluminum.
Do Retractable And Roll-Up Tonneau Covers Offer Good UV Protection?
Retractable tonneaus provide covered security when closed. But how much do they protect cargo from UV rays versus traditional covers?
Varying UV Resistance
Retractable tonneaus use different materials like vinyl, aluminum and polymer. UV resistance depends on the material. Aluminum models block virtually all UV when closed.
Gaps Along The Sides
When fully closed, most retractables have small gaps along the bed sides. These allow some indirect sunlight into the bed around the cover edges.
Potential For Sagging Over Time
Some vinyl roll-up models can slowly sag and puddle in the middle when closed. This creates gaps that compromise UV resistance.
Cargo Is Exposed When Open
Retracting the cover leaves the bed 100% exposed. So cargo gets no UV protection when driving opened. You’ll need to close it whenever parked.
A Good Compromise
For versatility, retractables allow quick access and UV protection when closed. But for maximum sun protection, non-retracting fiberglass or aluminum tonneaus are better.
Do Folding Tonneau Covers Offer UV Protection When Closed?
Folding tonneaus provide versatile bed access. But how well do they shield cargo from UV damage versus standard covers?
Varying UV Blockage
Folding covers use different materials like aluminum, vinyl and polymer. Aluminum models provide the best UV resistance when fully closed.
Potential For Gaps
Some folding covers can develop gaps between panels or along the bed rails over time. Gaps allow sunlight to enter the bed and damage cargo.
Reduced Cargo Space
When folded open, folding tonneaus consume valuable cargo area. Cargo has to fit in the compact front portion of the bed, exposed to UV rays.
Faster Degradation Possible
The hinges between folding panels are vulnerable points. Any material degradation here first leads to loss of UV protection as gaps form.
Folding covers offer quickly accessible, covered storage when closed. But for maximum UV protection, non-folding covers without potential gaps are preferable.
What Are Other Effective Ways To Shield Cargo From UV Damage?
Beyond your tonneau cover material, here are some additional tips to better safeguard cargo from sun damage:
Use A Bed Liner
An inner bed liner helps block UV rays penetrating through small gaps or thin areas in your tonneau. It creates a second barrier to the bed.
Add A Bed Cap
For maximum sun protection, adding a fiberglass or aluminum bed cap creates a fully-enclosed storage compartment sealed from light.
Use Sun-Resistant Storage Containers
Even with a tonneau, store sensitive items in opaque plastic bins, wood crates or thick canvas bags. Add an extra layer of UV defense.
Park In The Shade
When possible, park your pickup in shaded areas during the day to help extend your tonneau cover’s life and maintain its UV resistance.
Maintain The Cover Properly
Keep your vinyl or canvas tonneau cover cleaned and conditioned to prevent premature fading, tearing, shrinking or sagging that allow in UV rays.
Upgrade When Needed
If your tonneau cover shows signs of UV degradation, replace it sooner rather than later. Don’t wait for gaps or tears to appear.
Yes, most tonneau covers can provide excellent UV protection for your cargo when in good condition. Aluminum and fiberglass deliver the most complete sun blocking. Vinyl and canvas also offer superior UV resistance versus having an open bed.
But all tonneau materials degrade over time and need proper maintenance. Adding bed protection like liners and caps helps too. Invest in a quality tonneau cover and accessories to get the best UV protection and maximize your cargo’s lifespan.