Chapter 15 Hardscapes 413 Copyright Goodheart-Willcox Co., Inc. Ordering Materials Once the square footage of an area is calculated, volume must be deter- mined before ordering materials. For example, in an area covering 1000′ it may be necessary to add 4″ of gravel as a base for a hardscape installation. The 1000 would be multiplied by 4″/12″ or divided by 3. This would equal 333.3 ft3 (cubic feet). Since there are 27 ft3 in a cubic yard, 333.3 would be divided by 27 equal- ing 12.3 yd3. Most often gravel is ordered by the ton and a general conversion from cubic yards to tons is needed. If the generic conversion is used, 12.3 yd3 multiplied by 0.27 equals 3.33 tons (1 yd3 = 0.27 tons). Materials vary by weight due to their parent materials and moisture con- tent. Always add 5% to 10% for variance when calculating with general conver- sion factors. Tools and Equipment A variety of tools and equipment is used to prepare a site for landscape installation. Hand and power tools and large equipment are used for tasks such as removing or adding substrates and leveling and grading the surface. Large equipment is also used to dig ponds and holes for large plant materials. Consid- eration should always be given to damage that may occur from machine opera- tion and any space constrictions that may exist due to obstacles, such as large trees or minimal space between permanent structures. Machines with tracks tend to do less damage than wheeled loaders and may be a better option when the machine needs to travel over soft, fi nished areas, such as a lawn. A B C D E Area A is a trapezoid. Area = [(a + b) ÷ 2] × w a = 40′ b = 70′ w = 60′ Area = [(40′ + 70) ÷ 2] × 60′ = (110′ ÷ 2) × 60′ = 55′ × 60′ = 3300 ft2 Area B is a triangle. Area = 1/2 × b × h h = 32′ b = 200′ Area = 1/2 × 200′ × 32′ = 16′ × 200′ = 3200 ft2 Area C is a triangle. Area = 1/2 × b × h h = 25′ b = 15′ Area = 1/2 × 15′ × 25′ = 7.5′ × 25′ = 187.5 ft2 Area D is a rectangle. Area = l × w l = 500′ w = 200′ Area = 500′ × 200′ = 100,000 ft2 Area E is a circle. Area = 3.14 × r2 r = 40′ Area = 3.14 × 402 = 5024 ft2 The total area is A + B + C + D + E Area B = 3200 ft2 Area A = 3300 ft2 Area C = 187.5 ft2 Area D = 100,000 ft2 + Area E = 5024 ft2 Total 111,711.5 ft2 Any irregularly shaped area, such as a whale-shaped bed, can be reduced to one or more geometric forms. The area of each figure is calculated and added to obtain the total area. Example: 70′ 60′ 25′ 15′ 32′ 200′ 200′ 40′ r 500′ 40′ zizar/Shutterstock.com Figure 15-19. Landscape areas are often irregular in shape. It is common for theme parks to install beds in the shape of animals or animated characters. A combination of squares, triangles, and circles can be used to calculate area.