Understanding Performance Fabrics & Water Resistance
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Sailrite specializes in fabric, and much of what we offer falls under the category traditionally known as performance fabric. While the term may be used less frequently today, it remains the most accurate way to describe the majority of fabrics we sell. Performance fabrics are engineered with specific properties that allow them to excel in demanding environments. One of the most important of those properties is water resistance.
Why Water Resistance Can Be Confusing
Water resistance is not a single, universal trait. It can mean very different things depending on how and where a fabric is used.
For example, an upholstery fabric may bead liquid from a spilled drink and wipe clean easily. This performance might be described as stain-resistant or even water-resistant. However, the same fabric, when exposed to sustained outdoor rainfall, would quickly stop beading and begin to saturate.
The key takeaway: Water resistance must always be evaluated in relation to the fabric’s intended application.
Factors That Influence Water Resistance
Fiber Makeup
Some fabric brands emphasize the hydrophobic nature of their base fibers. Being hydrophobic means “water-fearing”, or in the case of fabric, it repels water. Conversely, hydrophilic means “water-loving” or natural absorption of water.
- Naturally hydrophobic fibers: Polyester, Acrylic
- Naturally hydrophilic fibers: Cotton, Linen, Rayon
While fiber choice contributes to performance, fiber content alone does not determine water resistance. Construction and treatments are equally important.
A Unique Outlier: Cotton Duck
Cotton is naturally water-loving, yet it was historically used for marine covers. When cotton duck fabric becomes wet, the yarns swell, reducing pore size and temporarily increasing water penetration resistance.
While effective in the past, modern synthetic fabrics now outperform cotton duck in durability, weather resistance, and longevity.
Fabric Construction
One of the most important construction factors affecting water resistance is weave tightness.
- Loose weaves allow water and air to pass freely
- Tight weaves limit pathways for water intrusion
Even hydrophobic fibers will not perform well if the fabric construction is too open.
Fabric Finishes (Not Coatings)
Many performance fabrics are treated with chemical finishes during manufacturing. These finishes are invisible and designed to improve water and stain resistance without changing how the fabric looks or feels.
Key characteristics of fabric finishes:
- Enhance water repellency and stain resistance
- Allow the fabric to remain soft and breathable
- Can diminish over time due to UV exposure, abrasion, and repeated cleaning
- Often require re-treatment to restore performance
Manufacturers can apply different amounts of finish. Heavier applications improve resistance but may increase stiffness and, in some cases, contribute to crazing.
For a detailed explanation of crazing—its causes, appearance, and prevention—please refer to our dedicated article on that topic here.
Moisture-Resistant Upholstery Fabrics
Upholstery fabrics must remain soft and supple, which limits the amount of finish that can be applied. For this reason, Sailrite classifies upholstery fabrics as moisture-resistant rather than water-resistant.
These fabrics:
- Resist stains and light moisture, such as spills, dew, or brief rain
- Will eventually wet out in sustained outdoor exposure
- Are not harmed by becoming wet
Recommended Moisture-Resistant Upholstery Fabrics:
- Outdura
- Sunbrella Upholstery
- SunRite
Water-Resistant Outdoor & Marine Fabrics
Water-resistant fabrics are designed for extended outdoor exposure and seasonal weather. These fabrics rely on a combination of:
- Hydrophobic fibers
- Tight fabric construction
- Durable water-repellent finishes
They shed rain effectively when properly tensioned and angled. Water must be able to run off the surface.
Flat areas or water-holding pockets may allow moisture penetration during prolonged exposure or under pressure.
Recommended Water-Resistant Fabrics:
- Sattler Marine Grade
- Sunbrella Marine Grade
- SureRite
- Top Notch 9
Knife, Roller or Dip-Coated Fabrics & Highly Water-Resistant Performance
Knife, Roller or Dip coatings are not the same as fabric finishes. These coatings are a visible layer applied to one or both sides of a fabric to significantly increase water resistance. It is often a urethane or an acrylic coating. The chosen coating method determines the coating thickness, but the same amount of coating can be applied using any method. Use of rollers or dipping (immersion) would generally coat both sides of the fabric.
Coatings:
- Add another barrier against water penetration
- Can elevate a water-resistant fabric to Highly Water Resistant status
- Reduce breathability compared to finished-only fabrics
- May slightly increase fabric stiffness
Highly water-resistant fabrics perform exceptionally well in demanding outdoor applications, even when a minimal fabric slope is present.
Recommended Highly Water-Resistant Fabrics:
- Sattler Yachtmaster
- Sattler Valora
- Top Gun
- Sunbrella Plus
Pro Tip: Combining fabric types is often ideal. For example, a powerboat enclosure may use a highly water-resistant fabric for the top panels and a standard water-resistant fabric for the side panels.
Waterproof Fabrics: Encapsulated, Laminated & Aggressively Coated
Waterproof fabrics are constructed differently from woven performance fabrics. They are typically made by encapsulating, bonding, or coating layers so that at least one layer is completely water-impermeable. When coating is involved, the material is generally a PVC (vinyl-like) barrier. For laminating, a film or membrane is bonded (using adhesive) to the base fabric. Encapsulated fabrics are base fabrics that are embedded in plastic.
Common characteristics:
- Withstand sustained, heavy rainfall without leakage
- Do not rely on chemical finishes or re-treatments
- Often have a different appearance or texture on each side
- Feel more plastic-like than woven fabrics since the coating is often vinyl or film
- Must be vented in fully enclosed applications to prevent condensation
Recommended Waterproof Fabrics:
- Stamoid
- Sunbrella SeaMark
- Sattler Trio
- Weblon Regatta
Water Resistance Definitions
Moisture Resistant
Designed to resist stains and light moisture. Will wet out during prolonged exposure.
Water Resistant
Designed for outdoor use where rain can run off the surface. May leak under pressure or pooling.
Highly Water Resistant
Near-waterproof performance achieved through knife, roller or immersive coatings. Excellent for demanding outdoor applications.
Waterproof
Constructed with impervious layers that do not leak unless damaged. Requires venting in enclosed uses.
Final Tip
On the Sailrite website, customers can filter fabrics by selecting Fabric Special Features within the Fabric category to narrow options by performance level.
Always review product descriptions to confirm appropriate use. Some products—such as seating vinyls and bag fabrics—may also be labeled as water-resistant or waterproof but are intended for different applications.