Catio mesh and roofing — what to choose and why
Choosing welded wire mesh for a catio by opening size, gauge and coating, fixing it properly, and picking a roof that handles sun, rain and snow.
· 3 min read · OpenCatio3D editorial · general guidance, not veterinary, legal or engineering advice
Mesh is the barrier between your cat and the world, and the roof decides whether the catio is pleasant in July and standing in February. Both deserve more thought than they usually get.
Mesh: three numbers and a coating
Opening size. The rule of thumb among cat owners is that if a cat can get its head through, the body follows. Kittens and small cats fit through surprisingly small gaps. Most catio builders use 1 × 1 in or 1 × ½ in openings; fence meshes such as 2 × 4 in are too large for many cats.
Gauge. Wire gauge runs backwards: 14 gauge is thicker than 16, which is thicker than 19. Heavier wire bends less when a cat climbs it or a raccoon pulls at it. Hardware cloth is welded too, but is often lighter gauge than catio mesh.
Roll size. Rolls come in widths such as 24, 36 and 48 in. Spacing posts and rails to suit the roll width means fewer joins and less waste.
Coating. Galvanised after welding (GAW) coats the welds as well as the wire and generally lasts longer outdoors than galvanised before welding (GBW). Black vinyl-coated mesh is less visible and softer on paws. Whatever you choose, cut ends are sharp: turn them in, cover them with a batten, or file them.
Fixing mesh so it stays
- Fix along every edge, at close, even spacing — screws with washers or heavy-duty staples.
- Keep it taut; slack mesh invites pushing and climbing at the edges.
- Overlap joins and fix both layers to a frame member.
- Cover edges with a thin batten for neatness and to hide sharp ends.
- Check corners and where mesh meets the house, roof and ground — the classic escape points.
Roofs
Every catio needs a roof, because cats climb. Your choices:
| Roof | Pros | Cons |
|---|---|---|
| Mesh | Cheapest, light, full sun and air | Rain, leaves and snow come in; snow load on the mesh |
| Clear polycarbonate | Dry corner, light still comes in | Can trap heat in full sun; needs rafters and slope |
| Corrugated sheet | Shade and shelter | Darker underneath; needs rafters and slope |
| Partial (cover + mesh) | Shade and a dry spot, plus open sky | Two systems to detail |
A partial roof — solid cover over the half nearest the house, mesh over the rest — is a popular compromise for lean-tos.
Weather and roofs
- Heat: cats can overheat. Make sure part of the catio is shaded at the hottest time of day; under a clear roof that may need a shade cloth.
- Rain: give sheets enough slope to drain and send water away from the house wall.
- Snow: a mesh roof catches snow, which is heavy. In snowy regions, use a pitched solid roof, brush it off, or close the catio in winter. Heavy-snow and high-wind sites are flagged for professional review in OpenCatio3D.
See the shade and weather guide for more.
Frequently asked questions
What mesh size is best for a catio?
Openings of 1 × 1 in or 1 × ½ in welded wire are common choices. Smaller openings are safer for kittens and small cats.
Is hardware cloth good for a catio?
It is welded and has small openings, which is good, but is often thinner wire than purpose-chosen catio mesh. Heavier gauge resists damage better.
Does a catio need a roof?
Yes. Cats can climb mesh walls, so an open top is an escape route, and a roof also keeps wildlife out.