Cold-cure tarmac is a simple way to resurface an old tarmac drive or path. It comes ready to lay from a sack and can be rolled level with a heavy garden roller (or purpose designed roller hirecd from a tool-hire shop). Cold-cure tarmac comes in two colours – red or black – and is sold in 25kg (55lb) sacks. A single sack will cover just under 1m sq. (1sq.yd) at a thickness of about 12mm (1/2in). Each sack often also contains a separate bag of decorative stone chippings for embedding in the soft tarmac as an alternative finish.
It’s easiest to spread tarmac on a warm, dry day. If you are planning on working in the cold, store the materials in a warm place the night before so they are easier to work with. A couple of days before you lay the new cold-cure tarmac, pull up any weeds and grass growing through the old surface and apply a good, strong weed killer. Sweep the area clean and level out any potholes: cut the sides of holes vertically, clean out the debris, paint the inside with bitumen emulsion then fill with 18mm (3/4in) layers of tarmac, compacting each layer until the surface is flush with the surrounding level. To make a firm bond between the old surface and the new, on a dry day, apply a tack coat of bitumen emulsion to the entire surface to be covered. Mask off the edges and any surrounding areas to protect from splashes.
Stir the emulsion well first, and then pour it on. You can pour direct from the container, but you may find it easier to control if you decant the emulsion into an old watering can – without the ‘rose’ sprinkler on the end. Use an old stiff-bristled broom to spread the emulsion. Try to avoid splashing surrounding surfaces and don’t leave puddles of emulsion.
Let the tack coat set – this usually takes about 20 minutes. While this is setting, wash the broom in hot, soapy water. Shovel on and then rake the tarmac to a layer about 18mm (3/4in) thick. Use a straight edge – or the flat side of the rake – to scrape the surface and press down lumps with your foot. Spread three sacks of tarmac and then roll. Keep the surface of the roller wet to stop specks being picked up. Spread and roll the next three sacks of tarmac. If you want to use the decorative chippings scatter them now and then roll the whole area in different directions to compact it evenly.
Useful Tips – Protecting Tarmac
You can walk on cold-cure tarmac as soon as it’s laid – but don’t wear high heels or stilettos for a couple of days and wait two or three days before you drive or park a car on cold-cure tarmac so it sets firm.
Always protect tarmac from chemical spillage-especially oil and petrol from cars and power tools.
Although its not essential, edging the tarmac with a brick or concrete block edge will improve the appearance and also prolong the life of this vulnerable area.