The rainproof performance of camping tents mainly depends on the fabric [1]. Based on my years of experience working at Zhengzhou Yongsheng Tent Factory, I have listed several common fabrics for your reference.
The technical specifications of waterproof fabrics are based on their degree of waterproofing.
Waterproofing only involves coating the exterior with AC or PU. This is generally only used for children's or play tents.
300mm waterproofing is generally used for beach tents/sunshade tents or cotton tents used in dry, low-rain conditions.
80mm-1200mm waterproofing is used for regular, simple camping tents.
1500mm-2000mm waterproofing is used for mid-range tents, suitable for multi-day trips.
3000mm and above waterproofing is generally used in professional tents, treated with high-temperature/cold-resistant technologies.
Bottom material: PE is the most common material. The quality depends mainly on its thickness and warp and weft density. Better, higher-end tents use Oxford fabric, with a waterproofing depth of at least 1500mm.
The inner fabric is generally breathable nylon or breathable cotton. Quality depends mainly on its density. The rainproof performance of the outer tent fabric is still calculated based on the number of millimeters of water column it can withstand per square centimeter.
Most tents are rainproof to over 1500mm of water column, capable of withstanding moderate to heavy rain; some reach 3000-4000mm, able to withstand continuous downpours.
High-quality rainproof tent fabric not only has a high rainproof rating but also features thick, sealed seams to prevent water seepage.
While the outer tent fabric has a high rainproof rating, breathability is an issue. Even on a clear, rainless night, the inside of the outer tent will still be covered with water droplets after a night's sleep, especially when pitching a tent on damp ground such as grass. Accumulated water can even drip into the inner tent. Relatively speaking, outer tents with lower rainproof ratings accumulate less water inside than those with higher ratings.
This water is from the moisture exhaled by the occupants inside the tent, and from ground vapor condensing on the inside of the tent fabric. Because the outer tent is rainproof, rainwater cannot enter, and water vapor cannot escape. So when you get up in the morning, avoid shaking the tent too hard, or it might "rain" inside.
