- Measure both the length and width (length is side to side, while the width will be from the top of the roof ridge to the bottom of the eave) of the first roof face (which roof face you measure first is not important), using a ladder if necessary. make note of the measurements.
- Repeat Step 1 on the remaining roof faces.
- Add up the length and width measurements in separate columns.
- Call your local building supply store to verify what size metal roofing sheets they have in stock and obtain pricing information (the typical sheet size is two by eight feet, but alternate sizes are available).
- Divide the total sum of the width of your roof surfaces by two--this will tell you how many metal sheets you will need from side to side (assuming you are using two by eight foot sheets). Then divide the width of your roof by eight--this will tell you how many metal sheets you will need from top to bottom. Multiply these numbers to find the total number of sheets needed. Example: Roof measurement is 14 by 16 feet. 14 divided by two is seven, and 16 divided by eight is two. The roof will be seven sheets wide and two sheets long, so you will need 14 sheets total.
- Multiply the price per sheet by the number of sheets needed to find the total cost for the metal roofing material.
Things You Will Need
- Tape measure
- Pencil and paper
- Adding 10 percent to your material will assure that you have enough to finish the job and will insure against any damaged material. Check with a building specialist at your local building store to see what (if any) extra materials you might need for the installation. The fasteners needed for metal roofs can vary from application to application depending on existing roof conditions.