A good-quality waterproof jacket with a membrane construction should last a long time. It’s hard to give a specific time frame because it depends on use.
One of the big misconceptions that people have with waterproof jackets is when they see their jacket looks very wet and the water is not beading off like it did when new, they think the jacket’s not waterproof anymore. It’s not just a visual thing – the jacket can also feel a little bit more clammy, a bit heavier, and bit colder to wear.
This is the jacket “wetting out” but it does not mean that your jacket is no longer waterproof. It’s very unlikely that the water will be penetrating the waterproof membrane that’s in the jacket. It’s just the outer fabric that’s wetting out. The DWR (durable waterproof repellency) is a treatment applied to the outer of the jacket and it has basically worn off. That means the outer fabric is soaking up a bit more water.
When that happens you need to reproof your jacket. Follow the wash care instructions on the jacket, but effectively, it’s washing your jacket and then you apply some heat. So tumble dryers are a really good method, on a very low heat. That can reactivate the DWR.
At some point, you do also need to reapply the DWR. So you can do that through buying products that you can apply to your jacket through wash or spray. Again, you’ll need to activate those with heat.
Keeping it clean will also help extend the life of the jacket. Your body oils – the sweat and grease that you create – will eventually block up holes in your jacket and stop it functioning as well as it should. By washing and looking after the jacket properly, it can help get rid of that and extend the life of the product.