Materials and construction distinguish a quality tent from an econo-model. When it's pouring and you are tent-bound you'll appreciate walls that don't sag, a floor that doesn't leak, and vents that you can open despite the deluge.
High-Tenacity 30-denier ripstop polyester is tightly woven, then treated with a durable water repellency finish. The combination makes for an incredibly light, strong, water-shedding canopy fabric.
Coated fabrics are tested by sealing them over the bottom of a standing pipe, then filling the pipe with water until the fabric leaks. The resulting "water column height" is the maximum depth of water the fabric holds back. A 1000mm coating allows no leaks after one minute under 1000mm of water. We find 600mm for flysheets and 1000mm for floors to be the absolute minimums for real-world waterproofness. Fabrics with higher ratings offer greater water resistance when new; more importantly, they also retain their waterproofness much longer in the face of everday wear and tear.
The flies of MEC tents have 2000mm waterproof coatings. The floors, where most abrasion occurs, are made of ultra-bomber HT-Seal fabric. This strong yet lightweight 70-denier taffeta nylon has a high (210) threadcount, and a thick, high-quality polyurethane coating. HT-Seal is waterproof to 10,000mm and in abrasion tests stays waterproof up to eight times longer than the average tent floor.
Seams are waterproofed with factory-applied seam-sealing tape. However, some curves and angles are impractical to tape seal. As well, tape cannot prevent water from entering around zippers, or bound seams. Apply a dab of seam sealer to these areas right after you buy your tent for real-world waterproofing.