Chapter 6 Landscape paving.
Any paving material will work if it performs the essential function of separating your feet from the mud, but using paving in creative ways also enhances the constructed environment. In many projects the paved area is a wonderful source of esthetics, introducing color, texture, and materials that enhance the overall design of a project. Many paving choices available can be installed by a homeowner. Unit paving, such as brick and concrete paving block, dry-laid stone, and granular paving can be used for patios and walkways in many residential situations. These installations require time and effort but yield attractive and durable surfaces when successfully completed. Other paving types, including concrete and masonry, also provide exceptional surfaces, but these pavement methods typically require the special skills and expertise of the landscape contractor. Your choice of paving materials will require balancing design esthetics and your installation skills.
PLANNING AND PREPARATION FOR LANDSCAPE PAVING
Preparation for a paving project requires consideration of several site-related situations and an understanding of the installation methods for the selected material. Base preparation will be similar for all pavement methods, but the specifics of installation, such as patterns, edging, and finishing, will vary from one pavement to another. Carefully review the planning consideration noted below to determine whether it applies to your project. Some municipalities may restrict the amount of impermeable paving that can be installed, so that water runoff is reduced. Check with local officials before you begin, in order to avoid a mid-project change in plans.
Access to the Site and Delivery of Materials
Unless you plan to carry bricks by hand, you will need access to the site for motorized vehicles delivering base, paving, and edging materials. Plan a route that will provide access to the site for large equipment such as a delivery truck and for small equipment such as a skidsteer. Delivery of unit pavers close to the site typically requires access by a large truck with a loading boom. Delivery of granular paving will require access to the site by a dump truck or by a skid steer loader moving material from a stockpile. If possible, this access route should not cross over the prepared paving area. Plan the installation so that the pavers and other materials can be delivered and the excess removed without damaging a completed installation. This will save you time and money.
After your base has been completed and you have begun a paving installation, the highest quality and efficiency is achieved by moving through the project without pause. This requires that materials be ready for installation and that any equipment necessary for installation or cutting be on hand at the beginning of the project. A staging area where several pieces of material can be laid out will speed the selection process required when laying stone. It will also be beneficial to locate an area where additional paving and granular material can be stockpiled, so that you can refurbish the surface in the future, if necessary.
Measure and mark project locations to guide your initial excavation. Painting the limits of your project is easier than dodging strings and flags, because both people and vehicles can pass directly over a painted line without damaging it or becoming entangled in it. Mark and excavate an area that goes at least 2' beyond the edge of the proposed paved area to create an apron that can be used for construction and later used to gradually match the existing grade to the new paving. This apron also provides the space to extend base material l' beyond the edge of the project to support edge restraints. If the project edge is adjacent to a steep slope, a wider apron may be required in order to blend grades. This situation may also require installing a wall to support the paving; if so, install the wall before proceeding with any paving.
Excavation and Subgrade Compaction
Because paving creates relatively flat surfaces with slight slopes introduced for drainage, proper grade is important. Attempting to work with slopes that are too steep will make installation difficult and may result in surfaces that are too slippery to be safe. Slopes that are too flat will result in the ponding of water that does not adequately drain from the surface. A cross-slope of 2 percent (1/4" fall for every l' of horizontal distance) is recommended for most paving. Cross-slopes (an entire surface that slopes in only one direction) are the easiest to construct and the best for drainage. The slope on paving surfaces should always be directed away from structures and permanent improvements.
Using the most efficient means available, dig out excess soil until it is excavated to a uniform depth over the entire area to be paved. The base excavation should extend to the markings. To determine how deep you should excavate, add the paver thickness (anywhere from 1 1/2" to 3"), the depth of any sand setting bed (typically 1"), and the thickness of the base (typically 4"). For many paving surfaces, this will be approximately 8", but each dimension should be checked with materials suppliers and your design before excavation begins.
To check the excavation for proper depth while you are digging, place a string line from one side of the project to the other that is set at the same height as the proposed pavement surface, including the cross-slope. As you are excavating, measure the excavation depth from the string (Figure 6-1).Any vegetation and unsuitable soils must be removed. Areas that are over excavated should be filled with angular 1" crushed stone and compacted. When the excavation is complete, verify that the base is the proper depth and that it slopes in the direction you desire.
[FIGURE 6-1 OMITTED]
Undisturbed earth is preferable for subgrade, or the soil below the base. Because it is already compacted you can accurately determine the stabilized height of materials and construction that will rest on it. If a paving installation is constructed in an area in which the subgrade has been disturbed, proper compaction will be necessary. Compacting subgrade in paved areas of up to 1000 SF can be done with a hand tamper or using a vibratory plate compactor (vibraplate). Utility trenches under paved areas should be compacted in 6" lifts as the trench is backfilled. Small areas that cannot be accessed by a vibraplate should be hand tamped. An informal test of the base for firmness is to observe whether foot traffic or a loaded wheelbarrow passing over the surface leaves any rutting or depressions. Such conditions indicate incomplete or improper compaction or an unstable subgrade. Any poor soils encountered must be corrected by removal and replacement with suitable material. See the project: Fixing poor soil problems below your project, Chapter 4.
Utility and Related Preliminary Work
Because paving is not easily changed, it is important to ensure that other work that might impact an installation be completed before paving begins; for example, if walls are necessary to create the area for paving, they should be completed and thoroughly compacted before you begin paving. All underground utility lines in the area should be in place and trenches below the area paved, backfilled, and compacted. Empty conduit or piping can be placed under the paved area if future utility installations, such as lighting or irrigation, are anticipated.
Durable paving installations can typically be traced to a sound and stable base. Although there is a temptation to place pavement directly on soil, the quality and life of the project will be greatly enhanced by taking the time to prepare the area below the pavement with the same care as that applied to paving the surface. Adequate base preparation requires excavation of the site, examination of the subgrade for stability, correction of any problems, and finally placement and compaction of a suitable base material. Performing these steps carefully lays the foundation for a long-lasting pavement installation.
Installing the base for a paved surface CAUTION * Verify the location of all utility lines prior to construction. * Follow the manufacturer's instructions when using equipment. Time: 2-4 hours for every 100 SF of base prepared. Level: Moderate (8 steps. Digging required. Tools Needed: 1. Plan of project. 2. Marking paint. 3. Mason's twine. 4. Line level. 5. Four 2" x 2" x 2' long wood stakes. 6. 2-pound sledge. 7. 25' measuring tape. 8. Round-nosed shovel. 9. Square-nosed shovel. 10. Garden rake. 11. Wheelbarrow. 12. 10' long 2 x 4. 13. Hand tamper. 14. 10' long 1" diameter metal pipe. 15. Location for disposing of excavated soil. 16. Optional: Vibratory plate compactor. Materials Needed: 1. Angular 1" crushed stone, approximately 1 CF for every 2 SF of base area for a 4" thick base. Directions: 1. Use the paint to mark the site to be paved. The excavation for the base should extend a minimum of 2' outside the edge of the proposed paved area, but the base should be installed only 1' beyond the edge of the proposed project. The placement of base material may be made easier if the project edge is repainted after the excavation is completed. 2. Remove and dispose of all vegetative cover. Excavate and remove the remaining roots of larger plants. 3. Verify the excavation depth by adding the paver thickness, setting bed thickness (1"), and base thickness (4"). Establish a stringline (Figure 6-1), set at the desired finish height of the paving, including any cross-slope. If significant excavation is required, dig to the approximate depth of the base before installing stringline. 4. Excavate to the calculated depth over the entire base area (Figure 6-2). Check the depth of your excavation often by measuring down from the stringline. 5. Examine the subgrade for potential soil and water problems. If corrections are required, refer to Project: Fixing poor soil problems below your project, Chapter 4. 6. Place a 4 1/2" thick layer of angular 1" crushed stone over the excavated area (Figure 6-3); the layer will compact to approximately 4" thick. 7. Compact the base using a hand tamper or a vibratory plate compactor. Work from the outside edges into the center, and then repeat at an angle to the direction of the first pass. [FIGURE 6-2 OMITTED] [FIGURE 6-3 OMITTED] 8. Drag a 2 x 4 across the base and level the material to within 3/8" of the desired grade, using the stringline as your guide. Check for irregularities using a long pipe rolled over the surface. Paint around low and high areas. Add base material to low areas and recompact them. Use a rake to remove high areas (Figure 6-4). [FIGURE 6-4 OMITTED]
The beauty of many pavement types (brick, concrete paving block, stone) is enriched by the pattern used to arrange the individual pavers. A feel of craftsmanship is created by employing patterns that require more expertise to install than simply leveling a granular material. Many pattern choices are available, but you will find that most are variations or combinations of a few simple arrangements. Select a pattern and practice the placement of units within that pattern to determine whether that look is right for your project. Note that some patterns, such as herringbone and running bond, require more cutting than stacked bond and basket weave. Herringbone will also require constant monitoring of individual paver placement to maintain the pattern.
Stone paving requires a different approach to installation than unit pavers. The installation sequence for unit pavers is repeated over and over, because of their uniform shape. Stone paving units, however, can be irregular and inconsistent in size and shape, requiring you to examine each piece for fit with the pattern. You must not only view the piece from an esthetic perspective but also locate or trim pieces to create a stable installation.
Paving patterns CAUTION * Use caution when splitting paving material. Wear appropriate safety equipment, including gloves and safety glasses. Time: 1-2 hours. Level: Easy (10 steps. Tools Needed: 1. Chalk line. 2. A flat 5' x 5' section paved area for practice. No base is required. 3. Brick hammer. 4. Brick set. Materials Needed: 1. Paving material for practice. Twenty full pavers and 5 half pavers for each different material you plan to practice with. If practicing stone paving provide 10 pieces of stone paving. Directions: Practice for unit paver patterns: 1. Locate a beginning point for the pattern. This point should be along a straight edge. 2. Snap a chalk line that is perpendicular to the straight edge. Most patterns will begin along the straight edge and move outward along this chalk line, filling in diagonally. 3. Begin placing blocks according to the numbered sequence shown for each pattern: * Stacked bond (Figure 6-5). * Running bond (Figure 6-6). * Basket weave (Figure 6-7). * Herringbone (Figure 6-8). Practice for stone paving pattern: 1. Locate a beginning point for the pattern. This point should be located along a straight edge or in a square corner. 2. Begin placement of stone in the direction shown. This sequence will be based on the size and shape of stone available and is intended only to illustrate the selection and placement of stone. Work across the surface one row at a time. * Random irregular (Figure 6-9). 3. Use stone with straight sides along pavement edges. 4. Stone should make contact with adjacent stones in three places and should leave joints between stones of -" or less. 5. Replace stone or adjust placement to achieve the desired pattern. [FIGURE 6-5 OMITTED] [FIGURE 6-6 OMITTED] [FIGURE 6-7 OMITTED] [FIGURE 6-8 OMITTED] [FIGURE 6-9 OMITTED]
Splitting and shaping paving material
Certain paving patterns will require the installer to use portions of the paver to complete the pattern. For some paving materials, halfs and starter pieces can be purchased. In other situations, the paver must be split, or cleaved, by hand. Clay brick can be split using a brick set, a chisel-like tool with a wide blade, designed to separate the material along natural cleaving planes. Concrete paving block can also be cut using this method but does not always cleave evenly. Stone can be cut in a similar manner as clay brick, although there may be significant irregularities in the edges of the stone after being cleaved. As with any paving product, it will take practice to obtain good splits. Purchase extra material, so that mistakes will not leave you short of paving material for your project. If the material you are paving with is impossible to split, consider having a contractor cut the shapes you need using a wet masonry saw. If sharp edges of an individual stone or paver need to be removed to improve fit, shaping can be done using a brick hammer.
Splitting paving materials using a brick set CAUTION * When splitting any material, wear proper clothing and safety equipment, including gloves and safety glasses. * Use all equipment according to the manufacturer's instructions. Time: 15 minutes Level: Easy (7 steps. Tools Needed: 1. Brick hammer. 2. Brick set. Materials Needed: 1. Materials to split. Gather a collection of unit pavers and stone types to practice with. 2. Bed of sand on which to set pavers. Directions for splitting paving material: 1. Using the brick set, lightly strike the paver on all sides at the location where the material is to be cut. 2. Set the paver flat on the sand bed. Any solid surface will also work. 3. Align the brick set along the mark for the cut. 4. Strike the end of the set with a hammer. The brick should cleave at that point (Figure 6-10). [FIGURE 6-10 OMITTED] Directions for shaping stone: 1. Hold the stone firmly. 2. To reduce irregular splitting of the stone, strike the protruding piece from the side rather than the top (Figure 6-11). 3. Strike the stone with the blunt end of the brick hammer. [FIGURE 6-11 OMITTED]
Setting Bed For Unit Pavers
Pavements such as brick, concrete paving block, and dry-laid stone require a special layer of material between the base and paver to ensure that the surface is smooth and level. This layer, called the setting bed, is typically a 1" layer of sand that is smoothed by a process called screeding. To screed the setting bed, place two 1" diameter pipes on your leveled base (Figure 6-12). Mound sand on the base and spread it around the pipes. Place a straight 2 x 4 across both pipes. Using a sawing motion, pull the 2 x 4 across the surface, smoothing the sand as you go. The 2 x 4 should always maintain contact with the pipes. If voids occur behind the screed, fill with sand and rescreed. When finished, carefully lift the pipes out of the setting bed and fill the voids with sand. You can smooth any irregularities using a magnesium float, a flat-bottomed tool used for concrete finishing.
The setting bed removes any irregularities introduced during base installation and provides a surface on which the paving material can be easily set. The setting bed is typically placed and screeded just before the beginning of paving placement. If paving a large area, screed small areas of setting bed, lay pavement in that area, and then proceed to the next location. The sand in the setting bed is easier to work if it is lightly misted before placing pavers. Make the misting very light, so that the finished surface is not disturbed.
[FIGURE 6-12 OMITTED]
Edge Restraints For Paved Surfaces
Most paving materials require that the edges be held in place to prevent shifting and settling. The material that holds this paving in place is called edge restraint. Of the many methods that effectively restrain paving, preformed plastic edge restraints are the most common. You can place edge restraints in position, push them firmly against the paving, and anchor them using stakes or nails. You can place plastic edge restraints on top of the setting bed or remove the setting bed and anchor the restraint to the base. If your paving material is not held in place by a structure or other paved surface, you will need to install the edge restraint to ensure that your project will not deteriorate over time. (Figure 9-19)
In addition to preformed plastic you can use wood, concrete curbs, metal, or other materials to hold paving in place. These other types of edge restraint may require excavation and placement before you pave, or they can be installed after paving in a manner similar to that used with preformed plastic.
Installing Landscape Paving
Actual installation of the paving material is the last in this series of steps. Proper preparation of the site and the construction of a sound base will make installing the pavement surface easier. If all preparation has been done properly, completion of the surface should proceed smoothly and quickly.
Unit paver is a collective term that includes clay bricks, interlocking concrete pavers, adobe pavers, precast concrete units, and similar types of materials that are produced with consistent dimensions and installed as individual pieces. Unit pavers are among the most desirable and requested types of paving materials available because of the esthetics of the finished surface. This attractiveness is not without its price, however, because unit pavers are high in cost and require skill and effort to install.
Although the strength of properly installed unit-paver surfaces is very good, failure of base or subgrade under pavers can create safety and long-term maintenance problems. All unit paver types have numerous joints between the pavers, and even after a perfect installation, these joints could hinder snow removal. Poorly installed unit pavers can create tripping hazards if they shift. Most residential installations are intended for patios, walks, and areas that support predominantly foot traffic, but with an engineered base course, concrete paving block and brick can be used in areas in which vehicular traffic is expected.
Installing a patio using bricks or concrete pavers CAUTION * Use caution when cutting materials. * Follow the manufacturer's instructions when using equipment. Time: Varies based on size of project, 6-8 hours for a 10' square patio with minimal cutting. Level: Moderate (23 steps. Equipment operation, heavy lifting, and excavating required. Note: To install a durable pavement, a base course should be installed under your pavers. To install a base course, review the project titled "Installing the base for a paved surface". If pavers need to be cut, review the project titled" Splitting paving materials", or hire a contractor who has a wet-masonry saw. Tools Needed: 1. Plan of project. 2. Marking paint. 3. Roll of mason's twine. 4. 25' tape measure. 5. Round-nosed shovel. 6. Square-nosed shovel. 7. Garden rake. 8. Broom. 9. Wheelbarrow 10. 10' long 2 x 4. 11. Two-pound sledge. 12. Vibratory plate compactor with rubber boot covering. 13. Two 10' long 1" diameter pipes made of metal or PVC. 14. Magnesium concrete float. 15. Rubber mallet. 16. Tin snips or hacksaw. 17. Torpedo level. 18. Screwdriver. 19. Carpenter's square. Materials Needed: 1. Brick or concrete paving block approximately 4.75 bricks per square foot of patio surface. Concrete paving block quantities will vary in size, so confirm with your materials supplier. Order 5% extra for cutting and breakage. 2. Clean, coarse, and damp concrete sand or stone dust, enough sand or stone dust to place a 1" layer over the entire base area with additional concrete sand to sweep into joints after paving; approximately 2.0 CF for every 10 SF of paved area. Use volume formulas from Chapter 2 to calculate the amount of sand required. 3. Edge restraint, 1 linear foot for each foot of perimeter of patio or walkway you plan. 4. 12" x 3/8" spikes or edging stakes, one for each linear foot of perimeter of patio or walkway. Directions: Placement of setting bed: 1. Set two 1" diameter pipes directly on base. 2. Spread the sand evenly over the pipes and base. Spray dry sand lightly with water before screeding. 3. Set the 2 x 4 on top of the pipes and level the sand by dragging the 2 x 4 along the pipes (this process is called screeding). Using a sawing motion while dragging the 2 x 4 will help speed the process. Screed perpendicular to the rails when possible. 4. Screed only the area of setting bed that will be paved immediately. You may need to screed small sections to match existing grades. 5. When screeding is completed, lift out any temporary screed rails. Fill the voids left by the rails with additional sand, and smooth the filled areas to match the surrounding base with a magnesium float (Figure 6-12). Setting pavers: 1. Select and practice a paving pattern. 2. Install a soldier course around the edge of the area to be paved. If the entire area is not yet screeded, place the soldier course in the area that is screeded (Figure 6-13). 3. Identify a location to begin the paving. The center of a straight edge of the project is the best beginning point. Snap a chalk line perpendicular to the straight line on the setting bed to guide the placement of the first pavers (use the carpenter's square as a guide).A square corner can also be used to begin pavement patterns, but the corner must be truly square to avoid "pinching" the pattern. 4. Begin placing pavers according to the steps for the selected pattern (Figures 6-5 through 6-8). 5. Place the pavers using a straight-down motion, and do not twist or turn them once set on the setting bed (Figure 6-14). Place pavers with their sides in contact with each other. If a paver is too high or low, carefully lift it and add or remove sand below it. As the pattern moves outward, kneel on the set pavers to reach the edge. Avoid stepping or leaning on the pavement within one foot of an unrestrained edge. 6. Continue placing pavers, working across the interior of the area to be paved. 7. As the pavers fill the area, continue the soldier course of full pavers along the entire perimeter before beginning to install the pattern on the interior. 8. Check alignment of pavers using a string-line or straightedge. Adjust the position of the blocks using a putty knife or pry-bar. 9. Continue placing pavers in the desired pattern. Split partial pavers when required. Cut pavers may have to be gently tapped into place using a rubber mallet. An alternative to cutting half or partial pavers while the pattern is being installed is to place all full pavers first, then mark, split, and place partial pavers as the last step in the process. This will save time, because it will enable you to do all of the cutting required at once. (Figure 6-15). [FIGURE 6-13 OMITTED] [FIGURE 6-14 OMITTED] [FIGURE 6-15 OMITTED] Edging and seating pavers: 1. When all pavers have been placed, measure and cut a piece of edge restraint for each side of the paved area. 2. Carefully remove the sand setting bed directly under the edge of the paver. Place the edge restraint directly on the base (Figure 6-16). The edge restraint should extend a minimum of half-way up the thickness of the paver (Figure 6-19). 3. Hold the edge restraint in place, and, using the two-pound sledge, drive 12" x 3/8" spikes or edging stakes through the edge restraint and into the base. 4. Place the spikes at the beginning and end of every edge restraint piece, and every 12" around the edge of the paved area; this will prevent paving blocks from drifting outward from the paved area because of the action of freezing and thawing, running water, foot traffic, or other forces that may act upon them. 5. Backfill around the edge of the paved area. If planting the area around the paving use a material suitable for growing. 6. Sweep dry concrete sand into the joints of the pavers. 7. Sweep any stone or debris from the paved area. 8. Set a vibratory plate compactor with a rubber boot on the paved area, start it, and run it around the edge and over the entire surface. 9. Again sweep dry sand into the joints of the pavement to fill any voids that may have been created by sand settling into or flying out of the joints between the blocks because of the vibration of the compactor. [FIGURE 6-16 OMITTED]
The intricate textures and patterns of limestone, bluestone, granite, or slate patios result in a highly attractive paving surface. Balanced with the esthetics of stone are the higher costs and skill levels required for its installation. The availability of materials will have an impact on price, resulting in lower costs in areas in which stone is commercially quarried and available, and higher prices further away. Stone also carries with it concerns about stability and safety. Stone paving has surfaces and joints that can be irregular, creating the potential for tripping and making snow removal difficult. Any base failure or water below the paving could force the stone out of position, amplifying the problems. When properly installed, however, few other surfacing materials produce as attractive a finished private walk or patio as stone.
Installing a stone patio CAUTION * Use caution when splitting materials. * Follow the manufacturer's instructions when using equipment. Time: Varies, based on size of project; 8-10 hours for a 10' square patio with minimal cutting. Level: Moderate (20 steps. Heavy lifting and excavating required. Note: For a durable pavement, install a base course under your patio. To install a base course, review the project titled "Installing the base for a paved surface" presented earlier. If stone needs to be cut, review the project titled "Splitting paving materials", or hire a contractor who has a wet masonry saw. Tools Needed: 1. Plan of your project. 2. Marking paint. 3. 25' tape measure. 4. Round-nosed shovel. 5. Square-nosed shovel. 6. Garden rake. 7. Broom. 8. Wheelbarrow, 9. 10' long 2x4. 10. Rubber mallet. 11. Stone hammer. 12. Two 10' long 1" diameter pipes made of metal or PVC. 13. Magnesium float. 14. Torpedo level. Materials Needed: 1. Stone paving, approximately 1 ton of stone for every 30 square feet (SF) of paved area. Check with stone supplier for quantities required. Order 5% extra for cutting and breakage 2. Clean, coarse, and damp concrete sand or stone dust, Enough to place a 1" layer over the entire base area and to sweep between joints after paving; approximately 2.0 cubic foot (CF) for every 10 SF of paved area. Use volume formulas from Chapter 1 to calculate the amount of sand required 3. One bag mortar mix for every 10 SF of paved area. 4. Edge restrain. 1 linear foot (LF) for each foot of patio perimeter. 5. 12" x 3/8" spikes or edging stakes. One for each LF of patio perimeter. Directions: Placement of setting bed: 1. Set two 1" diameter pipes directly on base. 2. Spread the sand evenly over the pipes and base. Dry sand will need to be sprayed lightly with water before screeding. 3. Set the 2 x 4 on top of the pipes and level the sand by dragging the 2 x 4 along them. A sawing motion while dragging the 2 x 4 will help speed the process. Screed perpendicular to the rails whenever possible. 4. Screed only the area of the setting bed that will be immediately paved. Small sections may need to be screeded to match existing grades. 5. When screeding is completed, lift out any temporary screed rails, fill the voids left by the rails with additional sand, and smooth the fills to match the surrounding base, using a magnesium float. Setting stone: 1. Lay out stone before placing it on the setting bed to practice the pattern. Use large stones for all edges, and alternate large and small stones throughout the remainder of the project. 2. Identify a location in which to begin the paving. A corner of the project is a good beginning point. 3. Set the stone directly down, and do not twist or turn them once set on the setting bed. Place stones so that joints are less than 1/2" between stones and that each stone makes contact at three points with each neighboring stone. If necessary, shape stones with a stone hammer. If a stone sets too high or low, carefully lift the stone and add or remove sand below (Figure 6-17). 4. Continue placing stones, working along a diagonal moving out from the beginning point. 5. Check to ensure that each stone is flush with surrounding stones when in place. If it is not flush, lift it and add or remove sand as necessary. 6. Stones with irregular edges can be shaped slightly by striking with a stone hammer. 7. Avoid stepping within a foot of an unrestrained edge. 8. In areas in which a partial stone is required, mark a stone and split it (Figure 6-18). Install the split stone in the opening. Tap lightly using a rubber mallet if necessary to fit the stone fragment into position. [FIGURE 6-17 OMITTED] Edging stone: 1. When all stone is placed, measure and cut a piece of edge restraint for each side of the paved area. 2. Carefully remove the sand setting bed directly under the edge of the stone. Place the edge restraint directly on the base The edge restraint should extend high enough to cover a minimum of half the thickness of thestone (Figure 6-19). 3. Holding the edge restraint in place, drive 12" x 3/8" spikes or edging stakes through the edge restraint and into the base. 4. Place the spikes or stakes at the beginning and end of every edge restraint piece, flush against the edge, and every 12" around the edge of the paved area. 5. Backfill around the edge of the paved area. If planting next to the paving, fill with a material suitable for plant growth. 6. Sweep a mixture of 50 percent dry concrete sand and 50 percent mortar mix into the joints of the stone. 7. Mist the paving with water. [FIGURE 6-18 OMITTED]
[FIGURE 6-19 OMITTED]
Granular surfaces are typically found in drives, walkways, trails, and occasionally in outdoor living areas. Granular paving includes such materials as crushed stone, crushed brick, pea gravel, decomposed granite, and other permanent materials that are available as small pieces. You will want to consider carefully the location where you plan to place your pavement and the use to which it will be put before deciding on the material to be used; for example, the limited durability of thin applications of granular paving will limit them to locations that are primarily foot traffic with limited vehicular traffic. Granular pavements can be quite attractive, because they provide consistent texture and color, but installing them does not require a high level of craftsmanship.
Installation is easy and costs typically low for granular materials, advantages that recommend their use in residential settings. Granulars with permanent edgings such as stone, brick, or concrete can create useful walkways and outdoor living areas. However, some materials tend to be subject to such safety hazards as washouts, poor traction, and sharp particle edges. Granular surfaces tend to be quite labor intensive after the initial installation. Maintenance includes the constant need to maintain the edging, frequently level, clean up material that sticks to shoes and is tracked inside, and add more material to replace that removed by foot traffic, wind and rain erosion. Granulars similarly are not a recommended choice in areas in which snow removal is necessary, because snowblowers or shovels tend to remove a portion of the material each time they pass over the surface.
Installing a granular-material walkway Time: 1-2 hours for every 10' of walkway. Level: Moderate (7 steps. Lifting and excavating required. Tools Needed: 1. Plan of your project. 2. Marking paint. 3. 25' measuring tape. 4. Torpedo level. 5. Round-nosed shovel. 6. Square-nosed shovel. 7. Broom. 8. Wheelbarrow 9. Garden rake. 10. Sod roller. 11. Optional: other edge restraint methods may require additional tools to cut and install the material. Materials Needed: 1. Finely crushed granular material (that which passes through a 3/8" sieve. Every 10" of a 5' wide walkway will require approximately 18 CF of material. 2. Edge restraint. 2 LF for every 1 LF of walkway installed; if edging a patio, 1 LF for every LF of perimeter. 3. 12" x 3/8" spikes or edging stakes, one for each linear foot of perimeter of patio or walkway. 4. Disposal area for excavated soil. Directions: 1. Review the alignment of the pathway. 2. Mark both edges of the pathway using the paint. 3. Using a shovel, excavate the pathway area to a depth of 4". If areas of poor soil are encountered, correct the problem using the instructions found in the project "Fixing poor soil problems under your project". 4. Install edge restraint along both sides of walkway alignment. If cross-slope is important, place 2 x 4 across walkway and slope using torpedo level. 5. Backfill along outside edges of edge restraint. If planting along walkway fill with a material suitable for plant growth. 6. Place a 2" layer of granular material in the excavated area of the pathway (Figure 6-20). Use the sod roller to compact this layer (Figure 6-21). 7. Apply another 2" layer of granular material. Rake level and compact again. Material should be level with the top of the edge restraint. [FIGURE 6-20 OMITTED] [FIGURE 6-21 OMITTED]
Informal walkways can be constructed with loose pieces of paving arranged in a convenient stepping pattern. Stepping stones can be composed of any paving material, with flagstone used most often for informal walkway applications. These unmortared stepping stones placed on earthen or thin granular bases are inexpensive but are suitable primarily for private walks; areas with heavy traffic are not good candidates for this type of surface.
Installing stepping stones Time: 15 minutes for each stepping stone. Level: Moderate (7 steps. Light lifting required. Tools Needed: 1. Plan for the project. 2. Flour. 3. Round-nosed shovel. 4. Square-nosed shovel. 5. Wheelbarrow 6. Hand trowel. 7. Broom. Materials Needed: 1. Stepping stones, each approximately 12" x 12" x 2" thick; one stone for each 18" on path desired. 2. 2 CF of sand for each 20 LF of walkway. 3. Disposal location for excavated materials. Directions: 1. Review the plan for the pathway. 2. Lay out the stones in a comfortable stepping pattern (Figure 6-22, Step A). 3. When layout is acceptable, sprinkle flour around the edge of each stone to mark its outline (Figure 6-22, Step B). 160 4. Remove each stone and excavate a 1" deep base inside the outline for each stone (Figure 6-22, Step Q. Properly dispose of any plant material or soil excavated. Set the stone back in the base and adjust with the hand trowel if necessary (Figure 6-22, Step D). 5. If a stone does not sit level and stable, adjust using a small amount of sand under the stone. 6. Repeat the setting process for each stone. 7. Sweep stone surfaces clean. [FIGURE 6-22 OMITTED]
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|Publication:||Plan It, Dig It, Build It! Your Step-By-Step Guide to Landscape Projects|
|Article Type:||Professional standards|
|Date:||Jan 1, 2003|
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