The Terra Rosa Gear Hoodless Sleeping Bag Cover is made out of a soft grade of Tyvek called 1443r, which is a breathable, waterproof fabric with a very soft hand that feels like silk. It’s amazing stuff and doesn’t feel like house wrap at all.
Weighing, a miserly 5.47 ounces (155 grams), the Terra Rosa Gear Sleeping Bag Cover only costs $85 USD, making it quite affordable. Couple this with a lightweight tarp and you’ve got the makings of a very functional UL shelter system.
The problem with most bivy sacks and sleeping bag/quilt covers is that they’re often fairly expensive, especially ultralight ones that weigh under 6 ounces, and you can expect to pay anywhere from $100 up to $300 depending on the materials used.
The Terra Rosa Gear Hoodless Sleeping Bag Cover cover is not intended to be a standalone shelter like a bivy sack. It really is just a sleeping bag cover and not a full-on bivy with a mummy hood.
Size-wise, the sleeping bag cover is 71 inches (180 cm) with a flexible 19.7 inch (50 cm) width to accommodate sleeping pads. For example, it is big enough to fit an inflatable sleeping pad and a 20-degree puffy down sleeping bag without compressing it, and long enough that the top comes up to the top of one’s chest. This is perfectly adequate to prevent rain splatter or splashback from wetting the outside shell of your sleep system if you are sleeping under a tarp, and will even add a few degrees to your sleep system.
The Terra Rosa Gear Hoodless Sleeping Bag Cover has two double-stitched seams running down to the footbox, which is constructed separately, and sewn to the top half of the bag. The seams are not taped but can be seam sealed if you want to make the sleeping bag cover a little more weatherproof.
One thing to be aware of is that the Tyvek sleeping bag cover is easily dirtied if it the outside contacts the ground. To clean it, simply wipe it down with a damp cloth or plastic scrubber. There is no need to wash the sleeping bag cover in a washing machine to clean or soften it and I’d recommend you avoid doing this because it may pull the seams apart if they get caught in the agitator.
I haven’t experienced any condensation using the Terra Rosa Gear Sleeping Bag Cover, not even trace dampness on the outer shell of my sleeping bag. Although this is inconclusive, I’m inclined to believe that Tyvek is pretty breathable, based on my knowledge of the conditions that I was camping in (cold outside / warm inside) which usually results in some internal condensation in the bivy sacks and tents that I own.
The Terra Rosa Gear Hoodless Sleeping Bag Cover is an affordable way to minimize the impact of rain splatter in a UL tarp system or to prevent tent condensation from soaking your sleeping bag shell in a double-walled tent. While it is not seam taped, it can be seam-sealed to provide a better moisture barrier against heavier splashback or ground dampness. For $85, it’s a pretty good value and a good example of how to use alternative breathable fabrics to construct more affordable ultralight backpacking gear.
Disclosure: Terra Rosa Gear provided the author with a sleeping bag cover.SectionHiker is reader-supported. We only make money if you purchase a product through our affiliate links. Help us continue to test and write unsponsored and independent gear reviews, beginner FAQs, and free hiking guides.