Best slip and slides

Wham-O is unusually good in this category on the figures it does publish — full inflated dimensions for both lengths of the Triple is more than almost any competitor prints — and completely silent on the three that matter most in a real yard. That asymmetry is worth knowing before you shop on length alone.

The instinct is to buy the longest mat. For most households the better spec is how many children can slide at once.

A single-lane slide with three children is a queue, and a queue at a water game means two children standing wet in the wind while one slides. The Triple Wave Rider publishes three lanes across 82.5 inches — that is the difference between a race and a rota, and it is why it is our pick for anything other than a solo child.

The 26-foot Super earns its place differently. It is the longest single mat anyone in this category publishes a figure for, and Wham-O states that two can be connected, which is the only route to a fifty-foot run that appears on a manufacturer's own page. It needs a genuinely level lawn to work over that distance.

The water and splash games hub sets these out in full; the short version is that a slide is the most site-dependent product on this site.

• Slope. A very slight fall helps enormously. A real gradient is dangerous, because people arrive at the end far faster than they planned. If your lawn has a genuine slope, run the slide across it rather than down it.
• Hose pressure. Neither set publishes a required pressure. Sprayers are photographed at full municipal pressure; on a well system, a long narrow hose or the top of a hill, the same product dribbles. Turn on the tap the slide will use and watch before you buy.
• Run-off. Covered above, and worth repeating because it is the one people discover at speed.

Safety detail, including what the published age range means in practice, is in slip and slide safety.

A mat left in one place for a whole summer will kill the grass under it: it blocks light and the traffic compacts the soil, which is the same mechanism described in yard games and your lawn. Moving it every session solves nearly all of it.

Storage is the other half. Neither maker publishes a material, so we cannot tell you how it ages — but a mat put away wet and folded will mildew like any other coated fabric, and the same drying rule applies as everywhere else on this site. See winterizing yard games.

If you would rather not commit lawn to a mat at all, plenty of what is already in the garage plays perfectly well wet: games that play wet.