Protecting Pavement Edges

The unsupported edge of a newly paved surface is typically the weakest point of the pavement system. Therefore, we highly recommend that you backup the edges of your pavement with either stone or topsoil to add support. However, you must follow specific procedures to ensure the edges are supported properly. Below, you will find our recommendations on how best to proceed.

Stone
It is typically best to use either 2RC or 2A stone. Both of these stone types have a wide gradation of stone sizes allowing for good compaction. Ordinarily 2RC stone is used. It is important to use a stone that can compact so that it remains in place after being exposed to most weather conditions.

1. First, determine if you are able to handle a project of this scope. If not, you can contact us and we can give you an estimate to do the work.
2. Next, determine how much stone you will need. We can help you with this calculation, or you can use the following general calculation: 1 ton of compacted 2RC (or 2A) stone will cover 18 square yards at 1” thick.
3. Verify that you will be able to move the stone from a stockpile to where it is needed. As a point of reference, 1 ton of stone is equivalent to about 8 – 10 full wheelbarrows.
4. Order your stone and have it delivered to a centralized point.
5. Place the stone along the edges of the pavement. Grade it using a shovel and garden rake. Follow these important rules:
   1. Make sure the stone slopes away from the pavement to allow the water to drain off and away from the pavement surface. Typically, the stones will be thick along the pavement edge and feather out to almost nothing to achieve the desired slope.
   2. Stone shoulders are typically 2’ – 4’ wide to ensure a smooth transition to the surrounding elevations. Make sure they are wide enough that the slope is not too abrupt.
   3. The stones directly along the edge of the pavement must initially be left higher than the pavement surface. This is because when you compact the stone it will compress, and if done properly, result in being even with or slightly lower than the pavement surface. As a rule of thumb, you can use the following general calculation: 1.25” of stone loosely placed will compress to 1” when compacted.
6. Compact the stones using a vibratory plate compactor. Vibratory plate compactors are readily available at most equipment rental stores and are easy for the average homeowner to operate. DO NOT use a ride-on vibratory roller for this procedure – due to the slope, the roller may roll over and possibly pin you beneath it, causing serious injury or death. You must compact the stones thoroughly to prevent them from washing away during a rainstorm. If the stones are dry, wet them (if possible) prior to compaction for best results.
7. You have now successfully completed your stone shoulders. However, some maintenance will be required over time – especially after adverse weather conditions.

Topsoil
There are typically two types of topsoil you can use – screened and unscreened. Screened topsoil saves work in that you do not have to rake out the stones before seeding, but it is more expensive. Unscreened topsoil is cheaper, but you must spend time raking the stones out of it before seeding.

1. First, determine if you are able to handle a project of this scope. If not, you can contact us and we can give you an estimate to do the work or we can recommend a landscaper.
2. Next, determine how much topsoil you will need. We can help you with this calculation, or you can use the following general calculation: 1 cubic yard of topsoil will cover 36 square yards at 1” thick.
3. Verify that you will be able to move the topsoil from a stockpile to where it is needed. As a point of reference, 1 cubic yard of topsoil is equivalent to about 16 – 20 full wheelbarrows.
4. Order your topsoil and have it delivered to a centralized point.
5. Place the topsoil along the edges of the pavement. Grade it using a shovel and garden rake. Follow these important rules:
   1. Make sure the topsoil slopes away from the pavement to allow the water to drain off and away from the pavement surface. Sometimes it is necessary to re-grade a portion of the yard to get the water away from the driveway edge.
   2. The topsoil directly along the edge of the pavement must be placed ¾” – 1” lower than the pavement surface. If you do not follow this guideline, you will get hairline cracks along the edge of the pavement. Hairline cracks form along the edges when the topsoil bonds to the new asphalt and pulls the asphalt edge down with it as it settles. If you see this condition happening, you must immediately remove some of the topsoil along the edge down to ¾” – 1” below the pavement surface. Over time, the lawn will fill in this height differential.
6. If you used screened topsoil, you are ready for seed. Otherwise you must first rake the stones out of the unscreened topsoil. Place your seed and straw and water regularly. It is critical that you get the lawn established so the topsoil does not erode away during rainstorms.
7. You have now successfully completed your topsoil edge backup. However, some maintenance may be required over time – especially after adverse weather conditions or if someone drives off the edge.