Residential driveway thickness is typically a 50 mm compacted asphalt layer on a properly prepared aggregate base of crushed limestone, less than 10 mm size. The preferred Hot Mix Asphalt grades for driveways are HL3A ("driveway mix") or slightly coarser HL3 (roadway topcoat mix). Asphalt compaction density of 90% to 95% requires vibratory rollers with static pressure rating of 60+ psi (414+ kPa) beneath the drums. Edges may be compacted and finished using a vibratory plate compactor or hand tamper. We plan drainage carefully to ensure that water runs away from the building and towards ditches and catch basins. Asphalt pavement may not surface drain correctly if its "pitch" or "slope" is less than 2% (1/4 inch per foot). Standing water on asphalt creates icy sections, puddles and cracking over time. Given painstaking preparation of the aggregate base, an experienced paving crew can overcome less pitch when no other solutions exists, but time and labour costs during preparation and paving will be greater. It is preferable to use a paving machine to lay and "iron" the hot mix asphalt, however when size or confined space does not allow use of a machine, a credible result can be obtained by hand raking. Power rolling and tamping follows in either case.