Waterproof kit is the thing that keeps a household able to work outdoors in a British winter, and it is almost always retired years before it needs to be, for a fault that is not a fault.
So this page starts with a diagnosis rather than a repair, because the commonest complaint about a waterproof is not caused by a hole.
It is probably not a leak
How to tell: if the outer fabric looks dark and soaked rather than beaded, and the inside is damp all over rather than in one place, it is wetting out. A real leak is localised, usually at a seam, a zip or a wear point, and the outer fabric round it will still be beading.
This is the single most useful thing on this page, because wetting out is fixable in an evening with a wash, and a great deal of perfectly good kit gets thrown away for it.
Washing and reproofing
Counter-intuitively, a dirty waterproof is a badly performing waterproof. Body oils, sweat, mud and detergent residue all break down the repellent finish and attract water.
- Wash it. Use a technical cleaner intended for waterproofs, or the mildest non-biological liquid you have. Never use ordinary detergent powder, fabric conditioner or anything with softeners: all of them leave a residue that actively attracts water.
- Run an extra rinse. Residue is the enemy.
- Reproof. Wash-in proofers go in the machine and treat the whole garment including the lining. Spray-on proofers treat only the outer face, which is where it is needed, and are the better choice for anything with a breathable lining.
- Heat it, gently. Most durable water repellent finishes are activated by warmth. A tumble dryer on low, or a cool iron with a cloth between, or an airing cupboard. Check the care label first, and see boots and shoes for why fast heat is a bad habit generally.
- Test it. Sprinkle water on the sleeve. It should bead and run off.
Do this once or twice a season on anything in regular use, and before winter on everything.
Finding an actual leak
If it beads properly and still lets water in, look for the entry point.
- Seams first. They account for most genuine leaks.
- Wear points: shoulders under a rucksack, elbows, the seat, the point where a hip belt sits.
- Zips, which are rarely waterproof themselves and rely on a storm flap.
- Around fittings: pocket zips, hood adjusters, hem drawcords, anywhere something has been stitched through.
To find it: hang it inside out and spray the outside with a hose or a shower, and watch for where the inside darkens. On a tent, get inside on a wet night with a torch, or have somebody hose it while you watch from within.
Mark it while you can see it, with a bit of tape or a stitch of contrasting thread. You will not find it again when it is dry.
Seams
Taped seams fail by peeling. The tape lifts at an edge, water gets under it, and the lifting spreads. If the tape is peeling but sound, it can sometimes be reactivated with a warm iron over a cloth, following the maker's guidance.
If the tape has gone, seal the stitch line:
- Turn the item inside out so the coated face is accessible.
- Clean the seam with alcohol and let it dry completely.
- Remove any loose tape.
- Apply a liquid seam sealant along the stitch line in a thin continuous bead, working it into the needle holes rather than laying it on top.
- Leave it to cure fully, flat, usually overnight.
Match the sealant to the coating. Silicone-coated nylon needs a silicone based sealant; polyurethane coated fabrics need a polyurethane one. The wrong one will not stick.
On a tent, do the fly seams and the groundsheet seams, and do them before the season rather than in the rain.
Patching a tear
Clean and dry first, always. Alcohol wipe, let it flash off.
Round the corners of the patch. Square corners peel, every time.
Patch both sides for anything over a few centimetres, and make the patch generously bigger than the tear, at least 2 cm all round.
For a stitched repair on canvas or a heavy tarp: sew the patch on with a saddle stitch using waxed thread, then run seam sealant over the stitch line, because you have just made a line of holes in a waterproof fabric. That last step is the one people forget.
Field repair: a strip of self-adhesive repair tape on both sides gets you home and often lasts a year. Keep a small roll in every rucksack and in the tent bag.
Tarps and groundsheets
Simpler material, harder life.
- Eyelets pull out. Reinforce with a patch of webbing or heavy fabric before setting a new eyelet, and never set an eyelet through a single layer.
- The corners go first, because that is where the load is. Reinforce all four before the first use, not after the first failure.
- A tarp with no eyelet left can still be tied: wrap a small stone or a wooden ball in the fabric and tie the cord behind it. That is a genuinely strong fixing that adds no holes.
- Groundsheets fail from abrasion, not from tearing. Clear the stones before pitching, and use a footprint or a cheap sacrificial sheet underneath. Replacing a two pound sheet beats replacing a tent.
- UV is what kills tarps. Polypropylene builders' tarps go brittle in a single summer of exposure. Take them down when not needed, and store them in the dark.
Poles zips and the rest of a tent
- A cracked pole section: a splint sleeve slid over the break and taped is the standard fix, and the sleeve should be in the tent bag already. A tent peg and tape works in the field.
- Shockcord perished: replaceable, and it is what turns a bag of loose sections back into a pole.
- Zips: see zip repair. A tent zip that opens behind the slider is the classic squeeze-the-slider fix.
- Mesh holes: patch with mesh repair tape or stitch a patch of net over. Insects matter more than water here. See mosquito control.
The failure you cannot fix
Polyurethane coatings hydrolyse. On old tents, dry bags, rucksack liners and cheap waterproofs, the coating breaks down over years, especially if stored damp or warm. It goes sticky, smells faintly of vinegar or fish, and flakes off in sheets.
There is no repair. The coating is failing across the entire surface, not in one place. Scrubbing the residue off and reproofing gives you a fabric, not a waterproof.
Prevention is storage: clean, completely dry, cool, dark, loosely packed rather than compressed. That is the entire prevention and it works.
Storing them
- Never put anything away damp. This is how coatings hydrolyse, mildew grows and a tent is ruined in a cupboard over one winter.
- Dry completely, including the seams, the pole sleeves and the corners of the groundsheet where water sits.
- Loosely, not stuffed hard, and not in the compression sack for long-term storage.
- Cool and dark. Heat and UV both age coatings.
- Reproof before storage, not after.