Jointing sand (types)
Sand particles should typically be symmetrical and angular in shape. Particles that are too round and close to the same gradation will eventually wash out of the joints. Sand that is too soft will not be able to transfer loads properly.
Contractors have several different options available for sand. Polymeric sand is gaining in popularity among contractors for several reasons. Polymeric sand is unlike sand. Polymeric sand stays in place, stabilizes the work, follows movement of the pavers, reduces weed growth, keeps insects from penetrating between the joints and is available in different colors. Other jointing sands that are commonly used by contractors are mason sand, torpedo sand and stone dust.
Purpose of jointing sand
There are generally three functions for jointing sand:
1. It will act as a medium through which applied traffic loads are transferred between paver to paver.
2. It helps prevent pavers from being pinched together.
3. It exerts friction between the pavers to help prevent movement.
Typically when the joints between the pavers are completely filled with sand, the loads applied to the pavers are transferred to the surrounding pavers. This enables the paver units to act together, as a load bearing system. Joints that are not completely filled with jointing sand can cause the pavers to act independently, which might result in future pavement failure.
Pavers will tend to shift and rotate when exposed to various traffic loads. Joints between the pavers that are completely filled with sand will prevent this from happening. Most pavers are manufactured with spacing bars. These spacing bars create a space between the pavers, which allow for proper sand installation. Pavers that are installed without spacing bars will tend to pinch, resulting in the chipping of pavers in heavy traffic.
Jointing sand installation and final compaction
Before jointing sand is spread across the surface of the pavers. The pavers should be compacted. (See section 4.8 ). After your first compaction of the pavers, you can spread a liberal amount of jointing sand across the surface of the pavers. After you have spread the jointing sand, you need to sweep the sand into the paver joints. Once the jointing sand has been swept across the surface of the paver, you can vibrate the pavers with a plate compactor. When compacting the pavers with jointing sand, it is recommended to compact the pavers in two different directions. This will force the jointing sand down into the joints and interlock the pavers. After compacting the pavers, jointing sand should be applied to the entire surface again and swept into place. This will ensure that all the joints are being properly filled. You should repeat this process as many times as needed to fill all the joints.
Final inspection and cleanup
Once you have completed the jointing sand application, it is best to do an overall inspection of your project. The overall appearance of your project is very critical, especially to your clients.
It is best to remove any extra sand from the surface of the pavers prior to doing your final inspection. During your inspection, it is important to pay attention to the following:
1. All damaged pavers are marked and replaced.
2. All pavers are level and true to grade. The final surface elevations should not vary more than +3/8 in, under a run of 10 ft. The top of the pavers should be 1/8 to 1/4 in above the adjacent catch basins, drains and utility covers. The top of the pavers may be 1/8 to1/4 in above the final elevations to compensate for possible minor settling.
3. There is positive pitch for drainage to all drains and channels.
4. All joints are completely filled with sand.
5. All extra materials are removed from the job site ( i.E. Gravel, sand, garbage, pavers and pallets )
6. Schedule a final walk through with the client to ensure complete customer satisfaction.
7. Repair any punch list items they may address.
It is best to develop a project check list. A project check list can help minimize any future call backs from the client. It is best to go over the check list with the client and have them sign off on it when the project is complete.
Final statement: this study guide was developed to provide you with the knowledge required to obtain the highest of standards in the industry. By following and applying the principles in this study guide, you can significantly increase the success of your every project.
