Do you need a waterproof backpack for travel?
When it comes to choosing the right backpack for travel, one critical consideration is how well it can protect your belongings from water. However, the need for a truly waterproof backpack might not be as high as you think. In this post, we’ll delve into the differences between waterproof, water-resistant, and water-repellent backpacks, explaining how they are made and their ideal use cases.
We’ll also discuss why most travelers might be better off using water-resistant or water-repellent backpacks, along with some practical solutions like dry bags and waterproof laptop sleeves.
Waterproof Backpacks
Waterproof backpacks are designed to keep your belongings dry in the most extreme conditions. They're typically used for activities where there is a high likelihood of significant water exposure such as kayaking, canyoning, or heavy-duty hiking in wet climates. Waterproof backpacks are designed to withstand being submerged in water for extended periods, and they're overkill for most travelers.
How Are They Made?
- Materials: Waterproof backpacks are often made from heavy-duty materials like PVC (polyvinyl chloride), TPU (thermoplastic polyurethane), or coated nylon. These materials are chosen for their ability to create a barrier against water.
- Thickness: The material thickness can vary but is generally in the range of 500 to 1000 denier (D), providing a robust and impermeable layer.
- Manufacturing Process: The seams of waterproof backpacks are usually welded or taped instead of sewn. This process ensures that water cannot seep through the stitch holes, which is a common failure point in water resistance, but the welding process is expensive.
- Coatings: These backpacks often feature multiple coatings to enhance water impermeability. For instance, a TPU or PET film coating provides flexibility and abrasion resistance while ensuring no water can penetrate the fabric.
Typical Uses
Activities like kayaking, rafting, canoeing, or hikes that require portaging; anything where there's a high risk of your backpack being completely submerged.
Water-Resistant Backpacks
Water-resistant backpacks offer a level of protection against light to moderate rain, and even downpours for a limited amount of time. They're more than suitable for most travelers and hit the sweet spot of protection and cost-effectiveness.
How Are They Made?
- Materials: Common materials include treated nylon and polyester. These fabrics are not entirely waterproof but can repel water to some extent.
- Thickness: The thickness of water-resistant fabrics typically ranges from 200 to 600 denier, balancing durability and weight. The thicker the fabric, the longer it can resist water molecules passing through, but at the expense of backpack weight.
- Manufacturing Process: The seams are often sewn but may include some degree of sealing or taping to enhance water resistance.
- Coatings: These backpacks usually have a DWR (durable water repellent) coating. This treatment causes water to bead up and roll off the fabric rather than soaking in.
Note: DWR coatings can wear off over time, especially with frequent use and washing. Reapplying DWR sprays can help maintain the water-repellent properties.
Effectiveness in Various Situations
Adequate protection during brief periods of light rain to moderate rain, can handle splashes or spills, and will likely provide adequate protection even if you're backpack gets completely submerged for a brief moment.
Water-Repellent Backpacks
Water-repellent backpacks provide minimal water resistance, and offer the lowest level of protection from the elements, though they are likely to withstand light rain or drizzle for short periods.
How Are They Made?
- Materials: Typically made from synthetic fabrics like nylon or polyester with a light DWR coating.
- Thickness: The denier of these fabrics is often lower, ranging from 150 to 300 denier. Note that a thick fabric (800-1000D) with no coating may offer more protection than a thin fabric (100-200D) with coating.
- Manufacturing Process: Standard sewing techniques are used, with minimal or no seam sealing.
- Coatings: A light DWR treatment may be applied to repel water briefly, but it wears off over time.
Use-Cases
Ideal for city use and urban commutes where exposure to water is minimal. Can withstand short-term exposure to light rain but not heavy or prolonged downpours.
Waterproof Fabric Comparison Chart
| Feature | Waterproof | Water-Resistant | Water-Repellent |
|---|---|---|---|
| Materials | PVC, TPU, PET-coated nylon | Treated nylon, polyester | Nylon, polyester |
| Thickness (denier) | 500-1000 D | 200-600 D | 150-300 D |
| Seams | Welded, taped | Sewn, some taping | Standard sewn |
| Coatings | Multiple (e.g., TPU, PET) | DWR | Light DWR |
| Water Protection | Full immersion | Light rain, splashes | Minimal, light rain |
| Typical Uses | Water sports, heavy rain | Everyday travel, light rain | Urban commuting, light rain |
Water Resistance Rating Chart
Water resistance is often measured in millimeters (mm), or hydrostatic head, which indicates how much water pressure a fabric can withstand before it leaks. Here is a comparison of various fabric types and their typical water resistance ratings:
| Fabric Type | Water Resistance (mm) | Conditions |
|---|---|---|
| PVC | 10,000 - 20,000 mm | Submersion, heavy rain |
| TPU | 5,000 - 15,000 mm | Moderate to heavy rain, wet environments |
| PET Film | 5,000 - 10,000 mm | Moderate rain, wet environments |
| Treated Nylon | 1,000 - 5,000 mm | Light to moderate rain, light snow |
| Treated Polyester | 1,000 - 5,000 mm | Light to moderate rain, light snow |
| Standard Nylon | 500 - 1,000 mm | Light rain, dry snow |
| Standard Polyester | 500 - 1,000 mm | Light rain, dry snow |
Practical Solutions: Dry Bags and Waterproof Sleeves
For most travelers, a fully waterproof backpack is overkill. Instead, using water-resistant or water-repellent backpacks with additional waterproof solutions for specific items can be more practical:
- Dry Bags: Small, fully waterproof bags that can be placed inside your backpack to protect electronics, clothing, and other valuables. They're made from materials like TPU and feature roll-top closures for complete water protection. Thin (100-200D) material will provide adequate protection for 99% of use cases while remaining flexible enough to pack easily.
- Waterproof Laptop Sleeves: These provide an extra layer of protection for your laptop. They are typically made from water-resistant neoprene or TPU-coated fabrics and can safeguard your electronics from accidental spills or extended rain exposure.
Benefits:
- Cost-Effective: Investing in a few dry bags or waterproof sleeves is usually cheaper than buying a full waterproof backpack.
- Versatility: You can use these protective bags inside any backpack, making them versatile and convenient.
- Ease of Use: Easy to pack and access your gear without the bulk and stiffness of fully waterproof backpacks.
Conclusion
While waterproof backpacks offer unparalleled protection for extreme conditions, they are often unnecessary for most travelers. Water-resistant and water-repellent backpacks provide adequate protection for everyday use and light to moderate rain travel scenarios. Combining these with dry bags or waterproof sleeves for essential electronics and valuables is a practical and cost-effective solution that meets most travelers' needs.
By understanding the differences and making informed choices, you can ensure your belongings stay dry without compromising on comfort or convenience during your travels.
Reference Data
Durable Water Repellent (DWR): DWR is a common coating applied to fabrics to make them water-repellent. This coating causes water to bead up and roll off the surface. However, DWR coatings can wear off over time, especially with frequent use and washing. Reapplying DWR sprays can help maintain the water-repellent properties.
Thermoplastic Polyurethane (TPU): TPU is a versatile material used in waterproof backpacks. It provides excellent flexibility, durability, and resistance to abrasion and punctures. TPU-coated fabrics are commonly used in waterproof backpacks for their ability to create a strong barrier against water while maintaining a lightweight and flexible structure.
Polyvinyl Chloride (PVC): PVC is another material used in waterproof backpacks, known for its durability and complete water resistance. PVC-coated fabrics are thicker and more rigid compared to TPU, making them suitable for heavy-duty waterproof backpacks. However, PVC can be heavier and less flexible, which may not be ideal for all types of travel.
Polyethylene Terephthalate (PET) Film: PET film is used as a coating on fabrics to enhance water resistance. It is lightweight, flexible, and provides excellent durability. PET film coatings are less common than TPU or PVC but offer a good balance of water resistance and flexibility, making them suitable for high-performance waterproof backpacks.
References:
- https://blog.tortugabackpacks.com/waterproof-backpack/
- https://www.cabinzero.com/blogs/backpack/waterproof-backpack-vs-water-resistant-backpacks
- https://www.trekandtravel.com.au/blogs/trek-travel-events-and-blog/understanding-waterproof-breathable-membrane-ratings
- https://backpackinglight.com/forums/topic/6627/
- https://www.mountainwarehouse.com/expert-advice/what-does-2000mm-waterproof-mean
- https://www.revolutionrace.com/campsite/waterproof-vs-water-repellent-vs-water-resistant