Therm-a-Rest Z Seat | Lightweight Folding Foam Seat Pad
We designed the Therm-a-Rest Z Seat for anyone who refuses to sit on cold, wet, or hard ground. This ultralight accordion-fold seat pad delivers instant insulation and cushioning wherever your adventure takes you.
Closed-cell polyethylene foam provides reliable warmth even when damp, while the egg-crate surface contours to your body for surprising comfort. At just 2 ounces and smaller than a paperback when folded, the Z Seat disappears into your pack but makes every break feel like home. Whether you're glassing for game at dawn, watching your kid's soccer match, or taking a breather on the trail, our Z Seat keeps you comfortable and dry.
Z Seat construction & specs
Why closed-cell foam wins on the trail
We build the Z Seat from closed-cell polyethylene foam because it delivers two critical advantages over inflatable or open-cell alternatives: guaranteed performance when wet and zero maintenance. Each microscopic cell in the foam is sealed, so water cannot penetrate the structure. Drop the Z Seat in a puddle or sit on damp earth and it still insulates your body from the cold ground beneath.
Closed-cell construction also means our seat pad cannot puncture, leak, or fail mid-trip. There’s no valve to clog, no air chamber to rupture, and no babying required. We’ve watched hunters drag Z Seats across lava rock, climbers toss them onto granite slabs, and anglers kneel on them in river gravel—and the foam springs back every time. For anyone who needs bombproof reliability in a seat that weighs less than a pair of socks, closed-cell foam is the only answer.
Accordion-fold design for instant deployment
The Z Seat unfolds in one motion because we molded the foam in a continuous accordion pattern. Pull the top and bottom edges apart and the pad snaps into a flat 14-by-17.5-inch seat—no fussing with panels or figuring out which side is up. When you’re done, fold it back on itself and the pad compresses to a slim 5-by-14-inch rectangle that slides into any pack pocket or straps to the outside of your gear.
This fold pattern also creates natural flex points that let the pad conform slightly to uneven surfaces. Sit on a rounded boulder or a slanted log and the Z Seat bends just enough to cradle your body without feeling stiff. That same flexibility means the pad won’t crack or develop permanent creases, even after hundreds of fold cycles.
Egg-crate surface texture explained
We molded an egg-crate pattern into both sides of the Z Seat foam because it solves two problems at once. The raised dimples increase surface area, which distributes your weight more evenly and reduces pressure points. This makes the pad feel noticeably softer than a flat foam sheet of the same thickness.
Grip and air circulation
The egg-crate texture also grips fabric and prevents your pants from sliding around on slick surfaces. Sit on a tilted rock or a wet picnic bench and the dimples lock your position. Air can circulate through the valleys between dimples too, which helps moisture evaporate if you sit on damp ground. We’ve found this texture strikes the right balance between cushion, traction, and packability—dense enough to support your weight but textured enough to feel plush.
More closed-cell foam seating from Therm-a-Rest
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Common questions about the Z Seat
The Z Seat measures 0.5 inches thick when deployed. That half-inch of closed-cell foam provides enough cushioning and insulation for extended sitting sessions while keeping the folded size compact. The thickness remains consistent across the entire pad surface thanks to the molded construction.
Absolutely. The closed-cell foam handles concentrated pressure well, so the Z Seat works great as a kneeling pad for gardening, home repairs, or outdoor tasks. The 14-by-17.5-inch surface gives you plenty of room to position both knees comfortably. Many customers keep one in their car specifically for roadside tire changes and similar tasks.
The folded dimensions of 5 by 14 inches make the Z Seat too large for most back pockets, but it fits easily in cargo pockets, jacket pockets, or small backpack compartments. The slim profile means you can slide it between books in a daypack or strap it to the outside of your gear without adding noticeable bulk.
Yes. The closed-cell foam insulates effectively on snow and ice thanks to its 2.6 R-value. We've tested the Z Seat in sub-zero conditions and it prevents heat loss to frozen surfaces. Ice fishermen, backcountry skiers, and winter hikers use Z Seats regularly to stay warm during breaks. Just brush off any loose snow before sitting.
The Z Seat doesn't include built-in attachment straps, but its flat folded shape makes it easy to secure with any pack strap or bungee cord. Slip it under your pack's top compression straps, side compression straps, or use a small carabiner through the fold creases. Many people just tuck it inside a side pocket or lid compartment.
The 14-inch width accommodates most body types comfortably, though larger users may notice the edges of the pad don't extend as far past their hips. The 17.5-inch length provides good front-to-back coverage regardless of size. If you need more surface area, consider pairing two Z Seats side by side or stepping up to a full-length closed-cell sleeping pad cut to your preferred seat size.
Closed-cell foam is essentially indestructible under normal use. Our oldest Z Seats in field testing are over a decade old and still perform like new. The foam won't degrade from UV exposure, temperature extremes, or moisture. You'll likely lose the pad before it wears out. The only failure mode we've seen is mechanical damage from sharp objects, and even then the foam continues to function with minor cuts or gouges.