Benefits 1. The steel skeleton of steel sheds for vegetable greenhouses single column-free span is typically between 6 m -12 m, the largest land area. Pillarless structure 2. steel greenhouses, open acreage, good lighting effects, ease of mechanized operations. 3. steel pipe greenhouse vegetable greenhouses for full-frame, durable for longer life. Good loading capacity 4. steel pipe greenhouses, strong wind anti-snow capability.