POLY CARBONATE MULTI WALL SHEET HANDLING & STORAGE: Stack short sheets on top of longer ones, Store sheets Ina cool and dry place out of direct sunlight. To prevent solar heat buildup, avoid covering the stack of sheets with a dark tarp or either heat absorbing material. THIS SIDE UP: The UV-protected side of the sheets covered with printed film and must face towards the sun. CLEANING: Normal dirt and dust accumulation Is washed off by periodical rains.