Get matched with top paving pros in Metolius, OR

While blacktop is a type of asphalt, the terms should not be used interchangeably, as not all asphalt qualifies as blacktop. The primary differences are in their composition, production process, and ideal applications. Blacktop contains more stone than other types of asphalt and is heated to a higher temperature during production—300°F or more—while hot-mix asphalt is heated to between 275°F and 300°F. The ratio of bitumen (a tar-like crude oil) is a key differentiator, though sources vary: some state blacktop has less bitumen, making it less durable, while others claim it has a higher ratio. Due to these differences, asphalt is generally more durable and better for high-traffic areas like highways and streets, while blacktop is more suitable for playgrounds and residential driveways. For a driveway project, it is best to consult a professional to determine the most appropriate material.

Box fill refers to the maximum number of conductors that can be contained within a wiring enclosure box, as well as the total volume of the components. Determining the allowable number of conductors in a box requires adding up the number of conductors, clamps, support fittings, devices and equipment, and equipment grounding conductors to make sure you’re within the allowable volume.

The stones do not work well on uneven ground. If the stones are not buried into the ground and made level upon installation, they almost certainly will shift or crack on uneven ground. Additionally, rainwater or water from sprinklers can run under the edge of an uneven paver, causing erosion. In a freeze and thaw cycle, trapped water under the paver can cause the problem to worsen by shifting the stepping stones around. Use a bubble level to make sure the ground under each paver is as even as possible, even if the nearby ground is uneven.

Professional installers often include a deep layer of crushed gravel under permeable pavers to allow more runoff to soak through into the soil below. Many installations will include multiple layers of gravel, with coarser aggregate at the base and finer aggregate that sits on top of that bottom layer. Above the gravel, you’ll often find coarse sand that helps reduce paver shifting over time. Some permeable paver designs include a water collection system set into the gravel layer to route runoff to a safe area for disposal.