Corrugated tin roofing is an excellent material for temporary buildings or storerooms. Corrugated tin panels come in various sizes and you can get the size that makes best use of the roof joists you have.
Make sure you know how many corrugated metal sheets you will need. You can do this by dividing the width of the roof by the width of the metal sheet and the height of the roof by the length of the metal sheet.
Fix the Sheets
Arrange the first corrugated metal sheet so that it is at the bottom corner of the roof with a slight overlap at the side and front. Hammer roofing nails through the top of humps and use 16 to 24 nails per sheet. The second sheet will be fixed next to the first sheet with an overlap of one of the lumps to add strength and create a waterproof joint. Continue in this manner until the whole roof is covered. If a second row of sheets is required, they should overlap the first row by at least an inch.
This will give you a functional and waterproof roof but the same method could be used to replace a roof on a house if necessary.