© 2008 by Raymond Alexander Kukkee
A cool on-grade Sand-based Patio built with Concrete Pavers
A Simple Patio for Entertaining Leisure hours
Is a patio in the back yard for entertaining and spending leisure barbecue time one of your fondest wishes? This easy-to-build sand-based patio might be the solution. A sand-based patio can be an attractive, easy-to-maintain and functional center of back-yard activity for your family.
What is it?
A sand-based patio is an on-grade surface of pavers, bricks, stone, or slate that is dry-laid upon a bed of sand contained in a structure to limit movement and stability. No poured concrete footing is necessary, and no mortar is required in the construction, which is one of the main attractions of building a sand-based patio.
Careful planning is required for the specific type and shape of concrete paver, stone, brick, or surfacing stone you wish to use. Any specific pattern installed will require a bit more skill and additional planning. Plan for the type of containment structure you will use. Edging may consist of edging blocks, timbers, dimensioned lumber, or even fitted stone.
Let’s start with the most neophyte-friendly structure, a rectangular patio at ground level. In our patio project, we will use 2×6 treated, dimensioned lumber which is convenient, lasts for many years, and is easy to build with basic carpentry skills.
We will need the following tools and supplies:
• Carpenter’s line
• 4′ level
• Hand saw or power saw
• Shovel, pick, and enough labour, (or mini-backhoe service) to complete the excavation. • Carpenter’s hammer
• Screed (you can make your own, see the note below*)
• Broom • 5# sledge hammer for driving stakes
• 3-1/2″ spikes, galvanized, or equivalent 3″ anodized screws
• Pickets to lay out the excavation and framing
• Gravel: coarse, uniform, free-draining.
• Builder’s sand (clean medium grit sand)
• Concrete pavers, bricks or stones of your choice.
• Fiber spacer board
• Chop saw with a masonry cutting blade (required for more complex designs)
Special Considerations and Decisions
Some preliminary decisions must be made involving design and location. What shape will your patio be? Square or rectangular is always easier to lay out, but with adequate care, you can make your patio any shape you desire. Will your specialized patio design have complex angles?
Be prepared to cut stones if required, or buy specially curved stones for circles and curves. Will it be raised above the ground surface? The materials for containment the containment strip requirements will be more complex.
Will the patio be adjacent to the house foundation? If so, a fiber spacer board ” will be required to place against the foundation Type of stones, brick, or pavers. Some types are more easily cleaned, for example, around a barbecue area. Is the drainage adequate where you intend to build the patio, or does water collect at that location? If water drainage is a problem, see “How to build a French Drain” to address and correct that problem. Ensure drainage, including water from roof leaders is away from any building foundation.
Let’s Build the Patio
1. Lay out the area. Clear all debris, and excavate the sod or grass to a depth of 5 -6″. Do slice out the sod carefully to *re-use elsewhere. *Replace bad sections of grass, fill holes, or donate it to someone that needs it and who may be quite happy to haul it away for you!
2. Level the excavation and fit landscape fabric to prevent weed emergence through the base.
3. Apply wood stain of choice to the 2×6 framing material. (Alternatively, this treatment may be applied after the frame is assembled.)
4. Build and place the frame into the excavation. Square the first corner by using a 3:4:5 measurement ratio. Measure from the corner 3′, place a mark on the inside, top edge of the frame, measure 4′ down the other side of the corner and place a corresponding mark. Adjust and set the corner. When the distance from the two marks diagonally across the corner equals 5′ exactly , the corner is perfectly square. Construct the other sides, assembling the frame with galvanized spikes or anodized screws. Measure diagonally across both ways corner to corner to verify the structure is square and is the correct size. *Ensure the inner dimensions will accommodate the paver sizes and design you have chosen, allowing for spacing between each paver. Care at this stage will eliminate any cutting of pavers or making difficult modifications at a later stage.
5. Reinforce the frame joints with blocking on the outside of the frame and drive PT (pressure-treated) wooden stakes on the outside of the frame to hold it securely in position, square, and level. Fasten the frame securely to the stakes. Remember to set or trim the tops of the stakes below finished grade level if you want them to be invisible.
6. Install a layer of gravel for drainage and level it. Gravel should be a uniform, free -draining gravel with no large stones. Compact the gravel with a plate packer if you have one available, otherwise rake it level and tamp it thoroughly. Make sure you allow enough room to install a 2″ layer of sand on top of the gravel.
7. Install the layer of sand and screed* it uniformly level using a screed built using a long 2×4 screed or board to achieve a perfectly level sand surface. Note: * Make your own screed by notching out a 2×4″ to the thickness of the chosen pavers. For example, if the pavers are 2″ thick, cut out a notch 2″ deep on the ends of a straight 2×4 that is long enough reach across the frame. The profile of the screed will then be “dropped” in the center and you will use it to screed or level the sand evenly 2″ below the top edge of the form.
8. Remove any excess sand or add more as required. Pack the sand and screed it a second time for superior results.
9. Begin installing the pavers in the pattern chosen, using spacers to achieve a uniform, neat appearance. Use a carpenter’s line to obtain perfectly straight rows. Avoid walking upon, or disturbing the pavers once they are placed. Complete the placement of all pavers.
10. Fill the spaces between the pavers with sand carefully, by brushing the sand across the paver surface with the broom.
11. Settle the pavers with a vibrating packer if available, or roll with a water-filled roller to level the masonry uniformly. Brush more sand into the cracks as required, packing it tightly. *Hint: Spray the structure with water lightly. Water will help pack the sand into the spaces. Expect some initial settling over time regardless of method used. Where settling is observed, top up with sand and pack carefully as required.
12. Apply Sealer: Depending upon the type of paver, brick, stone, or slate you have chosen to use, it may also be desirable to apply a sealer to the finished masonry surface to minimize or prevent any staining by grease spatters from the barbecue, paint, or other spilled materials.
Now you know how to build a sand-based patio! Have fun, take your time, work safely–and get out the barbecue.
Is that Incoming I hear?