Wash Rothy's Shoes: Safe, Step-by-Step Guide

If you want to know exactly how to wash Rothy's without shrinking them or causing the outsoles to peel, you need a precise cold-water protocol. These highly engineered shoes require specialized handling to survive the laundry room.

To wash Rothy’s, remove the insoles and place both shoes and insoles in a micro-mesh laundry bag. Machine wash on a delicate cycle using cold water (15°C to 20°C / 59°F to 68°F) and a mild, enzyme-rich liquid detergent. Never use fabric softener or heat. Always air dry your Rothy's using plastic shoe trees or unprinted craft paper to maintain their shape; exposure to heat will permanently shrink the recycled plastic fibers and melt the structural adhesives.

The Science of Rothy's Care: Why Traditional Washing Fails

Understanding the unique material makeup of your shoes is mandatory for extending their lifespan and maintaining their premium, glove-like fit. Many consumers treat these synthetic flats like basic cotton canvas sneakers, resulting in warped toe boxes and peeling outsoles.

The Polymeric Structure of rPET

Standard Rothy’s are constructed from Recycled Polyethylene Terephthalate (rPET), a spun plastic polymer yarn represented chemically as $\ce{(C10H8O4)_{n}}$. Unlike natural plant fibers, rPET is highly oleophilic (oil-attracting) but hydrophobic (water-repelling).

As you wear the shoes barefoot, the plastic yarn acts like a sponge for skin sebum, sweat, and lipid-rich body oils. Over a few weeks, these accumulated foot oils oxidize, leaving a slick, oily residue inside the toe box and transforming the shoe into a breeding ground for bacteria. Standard washing without targeted bio-enzymes merely wets the surface, leaving these stinky lipids locked tightly inside the fibers.

The Glass Transition Temperature (T_g) Danger

The primary structural threat to your shoes is thermal exposure. The Glass Transition Temperature (T_g) of dry PET is approximately 70°C (158°F). At this threshold, the rigid polymer chains begin to relax and turn rubbery. However, when rPET fibers are wet and subjected to the physical agitation of a washing machine, this thermal threshold drops.

Washing these shoes in hot water or putting them in a drying machine causes the plastic polymers to permanently contract. This results in irreversible structural shrinkage. Just as we warn against thermal damage in our how to wash polyester guide, heat is the ultimate enemy of synthetic textiles.

Adhesive Delamination and Foam Degradation

The outsoles of these flats and sneakers are molded from Thermoplastic Polyurethane (TPU). They are bonded to the rPET upper using heat-sensitive, water-resistant glues. High-temperature washing or violent, high-speed spin cycles soften these adhesives. The result is adhesive delamination, where you will see the rubbery sole visibly peeling away from the knit. Simultaneously, the open-cell Polyurethane (PU) foam insoles will physically shred and lose their elastic bounce under aggressive mechanical washing.

Rothy's Material Care & Chemistry Matrix

Before touching a bottle of detergent, identify your specific shoe style. Different lines dictate different chemical and mechanical limits.

How to Wash Rothy’s: The 7-Step Protocol

Follow these seven professional steps to emulsify heavy body oils, lift surface soil, and protect the structural integrity of your footwear.

Step 1: Disassembly and Dry Soil Extraction

Begin by removing the PU foam insoles from the shoes. Take both the shoes and the insoles outside and gently knock the outsoles together to dislodge dried mud, sand, and gravel.

Next, use a soft-bristled horsehair brush to sweep dry dust from the rPET knit upper. Brushing dry soil away prevents it from turning into a thick, abrasive mud during the wash cycle, which can grind deep into the microscopic knit loops and cause permanent gray staining.

Step 2: The Sebum-Release Pre-Treatment

Because rPET strongly attracts lipids, the inner heel and toe box areas will hold highly concentrated body oils. You will often notice a darker, slick-feeling patch in these zones.

Spray the interior of the shoe with a targeted laundry pre-treater containing lipase enzymes. Lipases specifically cleave triglyceride molecules into free fatty acids and glycerol, rendering them water-soluble. Allow the enzymatic spray to rest on the fabric for exactly 10 minutes before washing.

Step 3: Bagging for Protection

Place both the shoes and the insoles inside a heavy-duty, micro-mesh laundry bag. Zip it completely shut. You must never wash these shoes loose in the drum.

The physical barrier of the micro-mesh bag protects the shoes against frictional pilling. Without it, the rough metal walls of the washing machine drum will abrade the synthetic yarn, causing tiny, fuzzy balls of plastic to form all over the exterior of your flats.

Step 4: Machine Configuration

Set your washing machine to the Delicate, Gentle, or Woolen cycle. Manually override the water temperature settings to Cold. You want the water calibrated specifically between 15°C and 20°C (59°F to 68°F).

Check the spin speed dial and drop it to Low or No Spin. High-speed centrifugal extraction generates intense G-forces that will violently twist the shoe, warping the thermoplastic outsoles permanently out of alignment.

Step 5: Detergent Selection and Chemistry

Measure a conservative dose-roughly 2 tablespoons (30ml)-of a mild, dye-free, liquid anionic surfactant detergent into the machine dispenser.

• For standard rPET Rothy's: Verify the liquid detergent contains lipase and protease enzymes to aggressively digest organic sweat and oils.
• For the Merino Wool Collection: You must switch to a specialty pH-neutral wool wash. Never use standard detergents containing proteases on the Merino line. Protease enzymes are designed to digest proteins; they cannot distinguish between the protein in your sweat and the keratin protein of the natural animal wool. They will literally eat holes in your expensive shoes. Similar to the strict guidelines in our wash Allbirds guide, protecting wool requires exact chemistry.
• Safety Warning: Do not add liquid fabric softener or chlorine bleach $\ce{NaClO}$ to the dispenser.

Step 6: The "Soft Companion" Wash Cycle

Never run the cycle with just the shoes in an empty drum. Add three to four "soft companions" to the wash load, such as lightweight bed sheets, white cotton T-shirts, or soft bath towels.

Washing shoes alone causes them to slam violently against the agitator or the glass door, risking impact damage to the TPU outsoles. Soft companions act as a physical shock absorber, smoothing out the aggressive mechanical action of the wash cycle. This buffering technique is the exact same method professionals use to wash Hey Dude shoes safely.

Step 7: The Capillary Air-Dry and Shape Lock

Extract the shoes and insoles from the mesh bag immediately after the final rinse water drains. Do not wring, twist, or squeeze the wet shoes.

Because rPET is synthetic, it absorbs less than 0.4% of its own weight in water. The moisture you feel is simply trapped mechanically between the knit stitches. To dry them quickly, insert adjustable plastic shoe trees into the toe boxes. Alternatively, stuff them tightly with rolled, unprinted white craft paper.

Lay the shoes flat on a ventilated drying rack in a dry room, far away from direct sunlight, air vents, or baseboard radiators. Allow the PU insoles to dry flat on a separate towel.

The unprinted paper will draw residual moisture out of the knit via capillary action. Meanwhile, the plastic shoe trees maintain outward tension on the rPET knit as it transitions from wet to dry, locking the shape perfectly in place.

Laundry Lab Pro-Tips for Perfect Rothy's

• The Vinegar Odor-Buster: If your shoes have developed a stubborn, musty basement smell, add 1/2 cup (120ml) of distilled white vinegar directly to the fabric softener compartment of your machine. The active ingredient is acetic acid $\ce{CH3COOH}$, which breaks down hard water mineral deposits and neutralizes alkaline bacterial byproducts, leaving the shoes smelling like fresh, clean linen.
• The Outsole Detail Hack: White outsoles inevitably turn yellow from asphalt oils and dirt. Before throwing the shoes in the washing machine, scrub the rubber edges with a melamine foam sponge dipped in warm water and a single drop of degreasing dish soap.
• The Color Migration Shield: If you are washing highly pigmented patterns (like cherry red flats or bold leopard prints) for the first time, toss a commercial "color catcher" sheet directly into the mesh wash bag. These sheets contain positively charged chemical compounds that magnetically trap loose, negatively charged dye particles suspended in the wash water, preventing dye migration onto lighter areas of the knit.

Critical Mistakes to Avoid

• Never Use the Sanitization Cycle: High-end washing machines feature sanitize or allergy cycles that routinely exceed 60°C (140°F). This massive injection of thermal energy approaches the glass transition temperature of wet rPET, shrinking the entire shoe permanently by up to two full sizes.
• Avoid Cationic Fabric Softeners: Liquid fabric softeners rely on cationic surfactants to make clothes feel fluffy. These chemicals leave a heavy, waxy, hydrophobic coating on synthetic fibers. This coating locks in bacteria, seals in foot odors, and destroys the natural breathability of the shoe upper.
• No Oxygen Bleach on Merino Blends: Avoid powders containing sodium percarbonate $\ce{2Na2CO3.3H2O2}$ when washing the Merino wool variations. While safe for pure plastic rPET, oxygen bleach quickly degrades natural animal proteins. It will weaken the tensile strength of the wool and turn the fibers brittle and yellow.
• Do Not Use Wooden Shoe Trees During Drying: Wet rPET acts like a wick. If you place raw cedar or wooden shoe trees inside wet flats, the plastic will draw out the natural dark wood tannins, leaving permanent brown chemical stains blooming across the interior of the shoe. Stick exclusively to plastic shoe trees or plain white paper.

Frequently Asked Questions (FAQ)

Can I put my Rothy's in the dryer?

No, never put Rothy's in the dryer. The intense heat of a tumbling dryer will warp the recycled plastic fibers, permanently shrinking the shoes. Furthermore, the thermal exposure will melt the water-resistant adhesives holding the soles together, ruining the footwear entirely.

How do I get bad smells out of my Rothy's?

To eliminate foul foot odors, you must neutralize the acids. Sprinkle a thin layer of sodium bicarbonate (baking soda) $\ce{NaHCO3}$ directly onto the dry insoles overnight. The alkaline powder reacts with the butyric acid from foot sweat, completely neutralizing the odor.

$$\ce{C3H7COOH + NaHCO3 -> C3H7COONa + H2O + CO2^}$$

Shake out the excess powder thoroughly before wearing.

Can you dry clean Rothy's?

No, Rothy's should never be dry cleaned. The heavy chemical solvents utilized in commercial dry cleaning machines (specifically perchloroethylene $\ce{C2Cl4}$) will rapidly dissolve the structural adhesives bonding the knit upper to the TPU outsole, destroying the shoe.

How often should I wash my Rothy's?

If you routinely wear the shoes barefoot, wash them every 2 to 3 weeks. Delaying the wash allows aggressive skin oils, acidic sweat, and dead skin cells to deeply penetrate the oleophilic plastic fibers, making stains and odors progressively harder to extract.