You can use cold asphalt to repair or resurface existing asphalt, or build a new path on a hardcore sub-base. But it isn’t suitable for the constructing new drives.
If you’re resurfacing an old path, it’s a good idea to spray it with weed killer about two weeks before putting on the new layer. If you’re building a new path, prepare a sub-base as you would for a patio and lay some edging kerb. But pick a fine day to lay the asphalt, as water doesn’t mix with bitumen emulsion.
To avoid staining your edging kerb, cover it with some hardboard or old timber (if you do get any splashes on it, you can remove them with some white spirit on a cloth). Spread a coat of bitumen emulsion on the sub-base using an old watering can without a rose. Then brush it across the surface with a stiff broom, if needed. Let the emulsion dry for about twenty minutes, during which time it’ll turn from brown to black.
Tip or shovel the asphalt on top of the emulsion, and rake it over the surface to an even thickness of about 20mm.
Wet the garden roller to stop the asphalt from sticking, then roll in several directions to level and compact it to a depth of about 13mm. Clean your tools with paraffin or white spirit when you’ve finished.