If you're going green for a greenhouse, then the 18' x 30' heavy-duty premium clear poly tarp from Tarp Surplus is the ideal pick. The tarp is perfect for greenhouses and patio enclosures whether it is for a residential or commercial use. The heavy-duty clear tarp is fashioned from a strong 14 mil polyethylene fabric that is rot resistant and waterproof. This tarp really can stand up to the year-round battling from the elements and that includes the sun. It even offers UV protection while still letting a healthy amount of sunshine in. This long-lasting clear poly tarp features grommets every 36" along with durable plastic reinforced corners that will keep it in place and prevent stretching. Installation is definitely a stress-free process. Don't worry about rips either. The 14 x 14 mesh count is tear-resistant. Finished poly tarps are always slightly smaller, so be sure to measure before ordering to get an exact fit. The 18' x 30' heavy-duty premium clear poly tarp will have a finished size of 17'6" x 29'6".