To estimate the amount of materials required for a home roofing project you must know how to take an accurate measurement of the existing roof surface. The same is true for re-tiling or installing a chimney. Knowledge is the key to a cost-efficient roofing job.
While often overlooked, calculating material costs is arguably the most important step a homeowner can take. Right roof measurements save significant time and money. The process is as follows:
- Determine Square Footage: Come up with a raw number calculated in square feet by measuring the roof in its entirety. For best results use a one to two hundred foot tape measure.
- Divide and Apply: Depending upon the type of replacement roofing material to be used, divide the raw square feet by the size of a given tile.
- Material Versus Structural Support: When replacing a standard asphalt-shingled roof with custom and extraordinarily heavy roofing materials, be sure to analyze the internal support structure of your existing roof.
- Calculate the Cost: Material is priced according to type and durability, but you must also figure in the cost of transportation. Likewise, you must be sure to count in the costs of any necessary structural changes to the existing roofing system.
- Place the Order: No one likes making mistakes. Before placing your order, take time to consult with a professional roofer, the trained advisers at the local lumber mill, or even a friend who has experience in the same type of roofing project. You can never have too much information in this matter of roof replacement and roof repair.
Simple Notes Concerning Roof Measurement
Before taking any measurements, it would be beneficial to divide the roof into partitions. This makes it easier to reach a final number of square feet. The process works like this:
Draw out the different sections of the roof on a worksheet. This helps you account for inclined parts of the roof or triangular sections. Parts of the roof where two angular pieces meet are sometimes referred to as a “valley”. The top sections where two sections meet are referred to as a “ridge”. After picking an order of how the sections will be measured, it is time to start!
When measuring the roof, the more precise the numbers are the better:
- Record measurements down to the centimeter so that a more accurate estimation can be drawn.
- Do not round numbers as this could prove to be costly. Cutting five centimeters off here and five more there can add up to a significant amount of space, especially with a large area such as a roof.
- Adjust for angles. Roof sections are often quadrilateral or even pentagon in shape. Divide such pieces into smaller parts that take the shape of a triangle or square.
- Calculate the area of the triangles. Take the base multiplied by height divided by two. The area of a square is simply base multiplied by height.
- Add the totals. After retrieving all individual calculations, add them up to get total square feet.
- Double-check your figures. Repeat the calculations. Ensure that no parts were left out.
Know Your Roofing Contractor
Roofing companies vary in their methods for reaching total square footage. Calculating your own roofing numbers helps prevent unnecessary waste, but you need to be on the same mindset as your chosen roofing contractor. One hundred square feet of roof is sometimes referred to as a “square” unit. For example, two squares are equivalent to two hundred feet of roof. In other words, if you calculated your roof as five hundred square feet, it is equal to fifty squares.