Learning Objectives

Notes

17.1
To understand the basic construction of a timber retaining wall. (TL)

Have students collect samples of landscape wood materials and describe the difference between pressure treated landscape timbers and railroad ties.

Have the students determine and list the factors that will define the load stress of a wooden retaining wall. (NUM)

Have the students describe the design considerations for a vertical timber wall and a modular wall, and the need for tie back systems.

17.2
To create a practical timber planter design. (CCT)

Have students describe the following design factors for a timber planter: purpose, design style, estimated stress loads, and corner bracing.

A planter could be built in the school yard or in the yard of a volunteer.

17.3
To investigate the use of precast blocks for a planter or retaining wall design. (IL)

Have the students collect data about the variety of blocks available and define their uses. They could develop design ideas that show where each type of block would be best used.

17.4
To understand the uses and installation of precast paving stone.

Have students prepare a plan for the use of precast pavers including sub-grade preparation, materials estimation, and estimated wastage for the project. Demonstrate how a project is priced. (NUM)

Have students demonstrate how to stake out and estimate the requirements for pavers. Demonstrate the installation of paving stones and show variations in colour and design patterns.

Tour a new building subdivision to view the way paving materials are used.

17.5
To prepare concrete forms and batch mix concrete by hand.

Forms can be created with dimensional lumber, if the finished shape has straight sides. To make curved forms, plywood can be used. It is best to hold the forms in place with wooden stakes that are driven below the top edge of the form so that the wet concrete can be screeded or leveled with a board.

Have the students research the types of concrete, their additives and application.

Review the fundamentals of making concrete. Discuss the ratios of materials. Discuss rebar, sealants, joints, curves, curing, strength, and aggregates.

Have students prepare small batches of concrete in a wheelbarrow or a simple box made from plywood and dimensional lumber. Ensure the materials are thoroughly mixed with a hoe or shovel.

Have students identify and demonstrate various ways in which concrete is finished: brooming, stamping, troweling, dyeing, and creating exposed aggregate surfaces.

Identify or be able to recognize concrete defects such as: scaling, dusting, blistering and discoloration. Have the students provide possible solutions to rectify these concrete defects.

Forms (that can be used several times), for a simple garden bench, can be created by the students. Concrete benches consisting of two square pillars and a top can be made with one form constructed of plywood with a centre divider, if each pillar is half the length of the top. The top and pillars can be glued together using a variety of sealants, silicone being one example.

These benches have several advantages: they are heavy and not easily moved, do not blow over, weather well, are inexpensive and are difficult to damage.

17.6
To prepare plans for enclosing a residential property. (TL, NUM)

Have students design a number of different plans to enclose a yard. This is usually accomplished by constructing a fence and gates. There are many styles and materials available to consider when doing designs.

The students could research the cost of enclosing a residential lot, 15.2 x 30.5 M (50 feet x 100 feet), for example, using different styles and heights of fence. Have the students prepare a cost estimation for the entire job including materials, construction and finishing.

Hedges may be an alternative closure method for consideration.