How to check a second-hand waterproof jacket

A rain jacket can look tidy in a listing and still have problems hidden inside. Turn it inside out, check the seams and read the care label before treating it as dependable wet-weather gear.

Read waterproof and breathability ratings

Waterproof rating (mm) measures the water pressure a fabric withstands in a lab. A 10,000 mm figure represents a 10-metre water column; 20,000 mm resists more pressure under the same test. It does not mean hours of rain. Check seams, zips and wear as well as the fabric rating.

• MVTR, in g/m²/24 h: How much water vapour crosses a square metre of fabric in a day’s test. Higher means more vapour transfer.
• RET: Resistance to vapour transfer. Lower means more breathable—the opposite direction to MVTR.

Compare figures measured by the same method. Vents and opening the zip also help release heat on a climb.

Membrane, DWR and seam tape

• Membrane: The waterproof barrier inside the fabric construction.
• DWR: The outer water-repellent finish that makes droplets bead and roll off. Renewing it helps the surface shed water.
• Seam tape: Strips covering stitched seams to stop water passing through needle holes. Check for lifted edges.
• Delamination: Bonded layers separating, often seen as bubbles or peeling. Reproofing the surface will not bond them back together.

Separate the fabric from the surface finish

GORE-TEX explains that durable water repellent, or DWR, helps water roll off the outer fabric. It is separate from the waterproof membrane. When the outer fabric wets out, comfort can suffer even while an intact membrane still provides its barrier.

That means a beading demonstration alone does not establish the condition of the whole used jacket. Equally, poor beading does not by itself identify the cause of a leak. Check the exact construction and maker’s care advice.

Look inside first

Ask for clear interior photos, especially around the hood, shoulders, collar and major seams. Look for peeling seam tape, bubbles, flaking or separating fabric layers.

Check visible holes, worn areas and previous repairs on the outside too. A wash or DWR treatment should not be presented as a guaranteed repair for damaged tape or delamination. If the fault is significant, get a suitable repair assessment before buying.

Operate the closures and try the fit

Run the main zip and pocket zips through their travel without forcing them. Check cuffs, drawcords and adjusters, including where they attach to the jacket.

• Wear the layers you expect to use underneath.
• Reach forward and overhead to check movement.
• Check hood adjustment and visibility.
• Confirm the hem and sleeves give the coverage you need.

For an online purchase, request garment measurements and compare them with a jacket that fits. A size letter alone varies between brands and models.

Allow for care without promising a cure

Follow the garment label and the manufacturer’s product-specific cleaning instructions. Heat and treatment advice is not identical for every waterproof fabric, so don’t apply a generic recipe.

Ask about known leaks and previous care, and include any realistic cleaning or repair cost in the total. Our condition-grade explanation helps you read the listing, but the actual fault description is what matters for this jacket.

Sources and current details

Buying guide. Sources checked 26 September 2026.

• Official source 1
• Official source 2

References for these explanations

Checked 26 September 2026. Patagonia: waterproof pressure testing; Rab: breathability tests; GORE-TEX: water-repellent finishes.

Updated 26 September 2026: added plain-language explanations of ratings, terms and buying choices.