Clear, prep and fill potholes in a tarmac drive using cold lay tarmac, compacted in layers for a lasting repair.
PH-01Pick the right weatherCold lay tarmac bonds best when the surface is dry and the temperature is above 5°C. Avoid working in rain, frost, or if rain is forecast within 24 hours, as the patch needs time to bed in before it gets wet.
PH-02Gather your tools and safety gearYou'll need gloves, safety glasses, a dust mask, a stiff yard brush, a bolster chisel and lump hammer, a garden trowel, and a hand tamper or a flat piece of timber to compact with. Lay everything out near the pothole so you're not walking back and forth mid-job.
PH-03Clear loose material from the potholeSweep out loose stones, dust, mud and any weeds growing through cracks. A wire brush helps get into the edges. The hole needs to be clean so the new tarmac can bond to the old surface, not to loose debris.
PH-04Square off the edgesUse the bolster and lump hammer to knock away any crumbling or loose tarmac around the rim of the pothole until you reach solid, firm material. A slightly wider, square-edged hole patches better than a ragged one, because the new tarmac has a clean edge to key into.
PH-05Check the depth and top up the base if neededIf the pothole is deeper than 50mm, don't fill it all with tarmac. Add compacted sub-base aggregate (MOT Type 1) first, leaving the last 40-50mm for tarmac. Tamp the sub-base down firmly in 40mm layers so it doesn't sink later.
PH-06Brush out dust and apply a tack coatGive the hole a final sweep to remove dust, then brush a thin coat of bitumen emulsion (tack coat) over the base and sides. This isn't essential for small repairs, but it noticeably improves how well the new tarmac sticks, especially on older, drier surfaces.
PH-07Fill with cold lay tarmac in layersTip cold lay tarmac into the hole in layers no thicker than 50mm. Spread each layer roughly level with a trowel before compacting it, rather than tipping the whole bag in at once, which leaves the bottom loose and unsupported.
PH-08Compact each layer firmlyTamp each layer hard with the hand tamper, working from the edges into the middle. If you have a car free, driving a wheel slowly over the patch a few times gives an even stronger compaction than tamping by hand alone.
PH-09Level the final layer with the surrounding driveAdd your last layer slightly proud of the surrounding surface, by about 5-10mm, then compact it down flush. Tarmac compresses as it settles, so a patch left flush at this stage often ends up slightly sunken later.
PH-10Clean up and let the repair cureSweep any stray tarmac off the surrounding surface before it's walked in, and wipe tools clean with white spirit while the tarmac is still fresh. Keep the patch free of vehicles and foot traffic for at least 24 hours, and take any leftover tarmac or emulsion to your local household waste recycling centre rather than the bin, as most councils don't collect it kerbside.