Therm-a-Rest Z Lite Sol Sleeping Pad
The Therm-a-Rest Z Lite Sol is our accordion-fold closed-cell foam sleeping pad designed for fast-and-light backpacking, thru-hiking, and backcountry adventures where packability and bombproof reliability matter most. Unlike inflatable pads, the Z Lite Sol never needs air, never springs a leak, and sets up in seconds — unfold it on any surface and you’re ready to sleep.
We built the Z Lite Sol with dual-density ThermaCapture™ foam that reflects radiant heat back to your body while the egg-crate surface traps warm air in the dimples. At 410 grams for the regular length, it delivers an R-value of 2.6 for three-season use without the weight or bulk of traditional foam pads. The aluminized surface on one side boosts warmth; flip it over for a cooler night’s rest in summer.
Whether you’re counting grams on the Pacific Crest Trail or need a sit pad and emergency backup for winter mountaineering, the Z Lite Sol folds down to the size of a rolled yoga mat and straps to the outside of your pack. It’s the sleeping pad that simply works — every night, every trail, no pump required.
Key details
Closed-cell foam construction
The Z Lite Sol is built from crosslinked polyethylene foam — a closed-cell material that traps thousands of tiny air bubbles inside each layer. Unlike open-cell foam or inflatable pads, closed-cell construction is inherently waterproof and impervious to punctures, tears, and abrasion. You can pitch it directly on sharp rocks, wet ground, or snow without worrying about damage.
We laminate an aluminized ThermaCapture™ layer to one side of the foam using a solvent-free process. This reflective surface bounces radiant body heat back toward you rather than letting it escape into the ground. The egg-crate surface pattern adds a second insulation mechanism: the raised dimples create dead-air pockets that further slow heat transfer. Together, these features deliver an R-value of 2.6 — enough insulation for shoulder-season backpacking and most three-season trips.
Accordion fold and pack attachment
The Z Lite Sol folds accordion-style into a compact stack of foam layers rather than rolling into a tube. This folding pattern lets you attach the pad to the outside of your pack using a single compression strap, freeing up interior space for food, water, and gear. The regular size compresses to 20 × 5.1 × 6.3 inches; the small measures 16 × 5.1 × 6.3 inches.
When you reach camp, deployment takes three seconds: unfold the pad and lay it flat. No pump, no breath, no waiting. The rigid foam holds its shape immediately, and the dimpled surface grips tent floors and ground tarps to prevent sliding. In the morning, fold it back up and strap it on. We’ve found that many thru-hikers prefer external carry because the pad doubles as a frameless pack’s makeshift frame sheet — slide it into your pack’s back panel sleeve to add structure and lumbar support.
Dual-sided surface for year-round use
Aluminized side for cold nights
The silver ThermaCapture™ side is optimized for warmth. Use this surface facing up when ground temperatures drop below 40°F or you’re camping on snow. The reflective layer works best when your sleeping bag or quilt traps the radiated heat between your body and the pad.
Non-aluminized side for summer
Flip the pad over to expose the solid foam side when you need less insulation — late spring, summer, or desert camping where overnight lows stay above 50°F. The non-reflective surface sheds heat more efficiently, keeping you cooler without sacrificing the puncture-proof durability or instant setup that make the Z Lite Sol a year-round workhorse.
More closed-cell and ultralight sleeping pads
Rated 4.8 by verified buyers
Common questions about the Z Lite Sol
The Z Lite Sol has an R-value of 2.6, tested according to the ASTM F3340-18 standard. This provides reliable insulation for three-season backpacking in temperatures down to approximately 30°F when paired with an appropriate sleeping bag or quilt.
For colder conditions, many users layer the Z Lite Sol under an inflatable pad to boost total R-value and add puncture protection.
The accordion-fold design lets you strap the Z Lite Sol to the outside of your pack using a single compression strap or bungee cord. Thread the strap through the folded layers at the center point, cinch it tight, and clip or tie it to your pack’s exterior loops.
Many frameless pack users slide the folded pad into the back panel sleeve to add structure and create a makeshift frame. This technique distributes load against your back and frees up space inside the pack.
Yes, the Z Lite Sol works well as a winter camping pad when layered under a higher-R-value inflatable. The closed-cell foam provides puncture insurance on icy or rocky surfaces, and the ThermaCapture™ layer adds warmth. Used alone, the R-2.6 rating is suitable for temperatures down to freezing but not subzero conditions.
Flip the aluminized side up to maximize heat retention in cold weather. For snow camping below 20°F, pair the Z Lite Sol with an insulated inflatable to reach a combined R-value of 6 or higher.
The Z Lite Sol trades cushioning and packability for absolute reliability and zero setup time. Inflatable pads offer higher R-values per ounce and compress smaller, but they can puncture and require inflation. The Z Lite Sol never leaks, never needs air, and sets up in seconds — just unfold it.
Many backpackers choose inflatable pads for comfort on shorter trips and reserve the Z Lite Sol for long-distance hikes, alpine routes, or situations where puncture risk is high. Some use both: the Z Lite Sol as insurance under an inflatable for winter camping.
The regular Z Lite Sol measures 72 inches long and weighs 410 grams. It provides full-length coverage for most sleepers up to six feet tall. The small size measures 51 inches and weighs 290 grams — a torso-length option that covers your core sleeping zone while saving 120 grams of pack weight.
Ultralight hikers often choose the small size and place a pack or spare clothing under their legs for additional insulation. Both sizes are 20 inches wide and deliver the same R-2.6 insulation.
Shake off dirt and debris after each trip, wipe the surface with a damp cloth if needed, and let it air dry. The closed-cell foam does not absorb water, so there’s no risk of mildew or moisture damage.
Store the pad unfolded or loosely folded in a dry, cool place away from direct sunlight. UV exposure over years can degrade foam, but normal indoor storage preserves the pad indefinitely. No stuff sack or special treatment required.
The ThermaCapture™ coating can show surface scratches or scuffs after extended use on rocky or abrasive terrain. These cosmetic marks do not compromise the pad’s insulation or structural integrity — the underlying closed-cell foam continues to provide the same R-2.6 warmth.
Even with visible wear on the reflective layer, the pad remains fully functional. We’ve tested heavily used Z Lite Sols after thousands of trail miles and found no measurable loss in thermal performance.