Cat enclosures glossary
Plain-English explanations of the terms you will come across.
- Airlock entry
- A small double-door porch at the entrance to a catio. You close the outer door before opening the inner one, so a cat cannot slip out past you while you go in.
- Batten
- A thin strip of timber screwed over the edge of mesh to clamp it to the frame. Battens hold mesh far more securely than staples alone and cover sharp cut wire ends.
- Catio
- A cat enclosure, usually outdoors, that lets a cat enjoy fresh air and sunshine without roaming. The name blends cat and patio, and covers anything from a window box to a walk-in garden structure.
- Galvanised after welding
- Mesh dipped in zinc after the wires are welded, so the coating also covers and protects the welds. It resists rust better than mesh galvanised before welding, especially in wet or coastal areas.
- Inward-angled topper
- A mesh panel fixed to the top of a fence or wall on brackets angled into the garden. A climbing cat ends up hanging upside down with nothing to grip, so it cannot get over.
- Launch point
- Anything near a boundary or enclosure edge that a cat can jump from, such as a shed, tree, bin, water butt or high shelf. Launch points are the commonest cause of escapes from secured gardens.
- Mesh skirt
- A strip of mesh laid flat along the ground and turned inwards or buried at the base of an enclosure or fence. It stops cats digging out and foxes digging in.
- Microchip cat flap
- A cat flap that reads your cat's microchip and only unlocks for registered cats. It stops neighbourhood cats getting into the house through a house-linked catio.
- Permitted development
- Rights in England that allow certain building work without a planning application, provided limits on size, height and position are met. Most freestanding back-garden catios fall within these rights.
- Pressure-treated timber
- Timber with preservative forced deep into the wood under pressure, often sold as tanalised timber. It resists rot and insects far longer than untreated wood or timber with a brushed-on coating.
- Principal elevation
- In planning terms, usually the front wall of a house facing the main road. Outbuildings, including catios, in front of the principal elevation are not covered by permitted development in England.
- Roller bar system
- A smooth bar fixed along the top of a fence or wall that spins when a cat tries to grip it. It stops the cat getting purchase to pull itself over the boundary.
- Twinwall polycarbonate
- A lightweight, rigid roofing sheet with two skins separated by small channels. It lets light through, sheds rain and is a popular roof for catios because it is light enough for timber frames.
- Welded wire mesh
- Mesh made from straight wires welded together at every crossing point, so it keeps its shape and resists pushing and chewing. It is the standard choice for cat enclosures, unlike twisted chicken wire.
- Wire gauge
- A number describing wire thickness. The scale runs backwards, so 16 gauge wire is thicker and stronger than 19 gauge. Thicker wire resists foxes and determined cats better but costs more.
Last updated 6 November 2026