Polyester vs Fibreglass Mesh: Which Lasts Longer?
Magnetic fly screens for balcony doors are usually sold in one of two mesh types: polyester (sometimes branded as "Prime" or standard fabric) or fibreglass. Both block insects and let air through. The difference shows up after months of sun, wind, and — if you have them — pets treating the door like a scratching post.
Polyester mesh
Polyester is lightweight, translucent, and typically the most affordable option. It handles normal foot traffic well: adults and children walking through dozens of times a day rarely stress the weave. For a second-floor balcony with moderate use and no direct afternoon sun, polyester often lasts several seasons.
Weak points: prolonged UV exposure can weaken fibres over time; sharp cat claws can snag and tear standard polyester; very windy exposed terraces may push the mesh against rough frame edges repeatedly.
Fibreglass mesh
Fibreglass (or fibreglass-reinforced) mesh is denser and stiffer. Manufacturers market it as more scratch-resistant, UV-stable, and tear-resistant — which matches real-world use on ground-floor patios and south-facing balconies. Some listings also describe flame-retardant fibreglass; that refers to the material's fire behaviour, not everyday insect blocking.
Trade-offs: fibreglass screens usually cost more; the mesh can feel slightly less flexible when new; you still need correct sizing and a secure top strap — premium fabric does not fix a loose mount.
Quick comparison
- Everyday adult use, shaded balcony: polyester is usually sufficient.
- Cats or dogs using the door daily: fibreglass or reinforced "VP"-type fabrics hold up better.
- Full sun on the mesh most of the day: fibreglass degrades more slowly.
- Tight budget, standard 90 × 210 cm door: start with polyester; upgrade if you see tears in year one.
What about "VP" or hybrid fabrics?
Some brands sit between basic polyester and full fibreglass — thicker weave, stronger magnets, wider top Velcro. Think of these as durability upgrades for households that outgrow entry-level mesh but do not need the top fibreglass tier. They are still a rational choice when pets or wind expose cheap polyester quickly.
Mesh is only half the story
Even the best fabric fails if magnets do not meet or the top strap sags. Compare magnet closure quality and strap width (3.8 cm or more on upgraded models) alongside material. On windy balconies, a continuous magnetic strip can close gaps better than scattered magnet blocks — regardless of mesh type.