The C&C cage guide

A C&C cage is cubes and coroplast: wire storage grids clipped into walls, standing in a folded sheet of corrugated plastic that forms a solid waterproof base. Sizes are quoted in grids, so a 4x2 is about 10.6 square feet — which clears the published preferred area for two guinea pigs — and a 6x2 is about 15.8, which clears the preferred figure for four. It costs roughly what a large pet-store cage costs and gives two to five times the floor.

What the sizes mean

Grids are nominally 14 inches square, so the naming is grid count by grid count. In practice the finished internal dimensions are slightly less than the arithmetic suggests, which is why we use manufacturer-published figures rather than multiplying.

The useful conclusion: 4x2 is the entry point, because it is the smallest size that clears the preferred figure for a pair rather than only the minimum. A 3x2 clears the 7.5 square foot bare minimum and misses 10.5. A 2x2 clears nothing.

What you are actually buying

• Grids. Powder-coated steel storage-cube panels. A 4x2 uses about 12 grids for the walls. Some kits substitute clear acrylic panels for part of the wall, which is cosmetic.
• Connectors. ABS plastic corner pieces that clip grids together. About 24 for a 4x2. These are the part that eventually breaks and the part that is cheapest to replace.
• A correx base. Corrugated polypropylene, scored and folded so the sides turn up several inches. This is the whole floor and the whole waterproofing, and it is one sheet.
• Optionally a stand, which raises the cage to a working height and supports the base along its length.
• Optionally a loft, which is a raised platform with a ramp. Nice enrichment and it does not count towards the floor figure.

The three things people get wrong

1. Not supporting the base

The most common mistake and the most annoying to discover. Correx is light and it flexes: a 4x2 base on an unsupported span sags in the middle, which pools urine at the low point and eventually creases the sheet permanently.

The base needs support across its whole footprint — a table, a purpose-made stand, or a sheet of plywood underneath. Two trestles will not do it, and a 6x2 needs support along nearly seven feet.

2. Turning the correx sides up too low

The correx sides are what stop bedding and urine reaching the grids, and the usual advice is to fold them up four to six inches. Lower than that and bedding gets kicked out through the grids; the guidance that matters here is the 12-inch wall height, which is measured on the grids rather than the correx, so the correx height is about containment rather than about the published figure.

3. Ignoring the bottom grid row with young animals

Grid apertures are wide enough for a very young guinea pig to get through the lower row. For adults this is irrelevant; for babies, line the bottom row with correx or mesh. Worth doing before rather than after you discover it.

Configurations worth knowing

• Straight rectangle. The default, the easiest base to cut and fold, and the one that gives the most usable continuous floor. Start here.
• L-shape. Fits around furniture, costs a more complicated base, and gives the same area with less run-up distance. Use it if the room demands it, not by preference.
• Divided. Two halves separated by a grid wall, which solves introductions, illness and a boar pair that has fallen out. Keep a spare grid or two for exactly this, the way we recommend for rabbits kept in pairs.
• With a loft. A raised platform reached by a ramp. Good enrichment, adds no continuous floor towards the published figure, and needs a solid non-slip ramp because guinea pigs are poor climbers and worse descenders.

Fitting it out

The base is solid and washable, which is exactly what the published flooring rule asks for, so you have a free choice of surface on top of it: two to three inches of paper bedding, or a fleece liner cut to the footprint. Standard C&C sizes are catered for by both liner brands we assessed, which is one more advantage of sticking to a standard size — see best guinea pig cage liners.

Everything else a C&C cage needs is in the guinea pig setup checklist: hay rack, two hides with two exits each, water, and enough floor left over that the animals can run.

One last point in favor of the system. Every component is individually replaceable: a bent grid, a broken connector, a creased base. Over a five-to-seven-year guinea pig lifespan that means the cage does not become rubbish because one part failed, which is not true of a molded pet-store cage.