By Michael Swiderski, Ph. D.More in Blog Cabin
Cobble Systems features cast cobblestones connected to cast-in grids to make handling and application easy. Cobblestone patterns and color options are available. The calculation of square-foot ground coverage is necessary before ordering from the nearest dealer.
The two-part epoxy grout mixture from EcoSystems is permeable when mixed with silica sand, allowing water to pass through the grout rather than running off into unwanted areas. Silica sand is available at local home improvement centers or block and brick masonry retailers. Bedding sand may not be used as epoxy joint sand. Only clean, dry silica sand may be used. This sand is often called medium-grade or coarse-grade sandblasting sand. Some contractors refer to it as #22 sand.
Grade is a term often used by contractors to indicate the slope of the land from one point to another. Grade stakes, driven into the ground, along with a 6' level and string line can be used to keep the grade consistent, either flat or slightly uphill/downhill. A laser level with tripod, which can be rented for about $50 per day, is a more advanced and accurate method for determining grade.
At the Blog Cabin 2011 site, a load of fill dirt was imported and graded downward, away from the house. This 20' x 50' top-filled area was outlined with tight nylon string. Additional grade stakes were set and string lines were pulled tight to calculate grade. The graded fill dirt was compacted using a 20” vibrating plate compactor, available for rent at about $100 per day.
A second load of material was delivered, piling 20 tons of crush and run gravel (3/4” and smaller) near the site. Help was needed to wheelbarrow and spread the crush and run into a four-inch-thick compacted base course material. Spreading gravel to grade with rakes and shovels is labor-intensive. Either grab a group of neighborly DIY supporters or rent a small skid steer. A skid steer is a back-saving option, available for rent at about $175 per day. The vibrating compactor compresses the leveled crush and run in prep for the final layer.
The final truck delivery dumped 15 tons of stone dust. This bedding material was also spread evenly to a three-inch thickness. An important step in the process is to level the stone dust. A screed-board system, using a straight board or aluminum tool, with level side boards, was set up to smooth out the stone dust to a level height. It takes three people to complete this phase of ground prep, two screeding and one filling in the holes with a shovel or rake.
Builder's Tip: Dirt, crush and run, stone dust: Most DIYers have had little experience with these building materials. Do not let 18 tons of gravel be an intimidator. Call the local sand and gravel yard. They will answer clarifying questions, provide square-footage coverage and thickness data, give prices per ton and deliver to the DIY site.
Purchasing Information: Not all sand and gravel prices are identical. Delivery distances, location of the rock quarry, types of gravel and quantities of load are all variables that affect costs.
Lay the sheets of stone down on the prepared base. The sheets link together, providing a continuous application over the prescribed area. Once a sheet of stone is laid down, it may be walked on gently. Continue laying the sheets of stone until the entire area is covered.
Builder's Tip: If a fan design is desired, lay stone sheets outside of the perimeter boundary. The rough edges can be trimmed away, leaving a smooth edge