The Art of Laying Tarmac

In our overview article about tarmac laying, we discussed the fact that it's not really a job for the ordinary handyman. This is because of the skill level required, the expense of getting in the specialist machinery, and knowing how to use it (see Tarmac Options For Your Driveway Or Patio). So in this article we'll discuss the key factors that lead to a well done job as a guide, to make sure that you know enough to follow what the contractors are talking about when they come and estimate for the job.

Club Together with Neighbours

One other point that's worth mentioning about tarmac is that although it's very cheap, possibly the cheapest form of hardstanding available, this is only true when the job is over a certain size. This is because of the high setup cost of getting the machinery and skills onsite.

So if you live in a street or estate where a lot of the drives are in need of repair, it might be worth seeing if you can get a few neighbours to club together. This will make the job easier for the contractor and that ought to be passed on to all of you in the form of cheaper drives.

Layers of Construction

As with most other driveway surfaces, there are a number of layers involved, starting with the foundations (see Excavating For A Driveway). Typically, excavations will go down to 16 to 18cm for a driveway or path, then a sub-base of crushed hardcore will go down and be rolled with a road roller. Edging Kerbstones, or a decorative stone or concrete block, whatever you have chosen, should then be laid and haunched on both sides so that they will be supported while the tarmac is laid.

The tarmac will go down in two layers, first the base and then the top surface known as the 'wearing' course. The base layer will use a larger grade of aggregate and has to be delivered in a heated lorry. Once laid roughly along the site of the driveway, the tarmac is spread out and levelled with large, sturdy rakes. The roller then comes over again to compact the base layer, only stopping when it no longer makes marks on the surface.

Top Surface and Finishing

The wearing course has smaller grains of aggregate so there's a finer, better looking and harder wearing top layer. In the future, if the job has been done right all the way through, the driveway can be rejuvenated by skimming the wearing course and re-laying it, a process known as 'overlay'. The laying is done in much the same way as the base course but with more care, and a professional crew will be looking for a tolerance of around half a centimetre across the levels.

The drive will set fairly rapidly and within an hour or so it will be available for careful use. It's best to avoid aggressive accelerating or braking for the first week or so, and in particular turning the wheels when the car is at a stand-still, something that's all too easy with a power-steered car.

Finding the Right Firm

The key to a top finish, however, has to be finding the right company to do the job. Look for at least three firms to come and quote for you, finding them by personal recommendation if possible (see our article Driveway Quotes And Estimates). Check how long they've been in operation, what their guarantees are, and ask to see jobs they have done where you can inspect the work and talk to the customers.

Never allow anyone who just knocks on your door on-spec to lay a tarmac drive at your property. At best, you'll end up with a job that's just a thin layer of tarmac over whatever was there before, and no one to complain to a few weeks later when it all starts looking ropey. At worse, you can find yourself coerced into paying far more than the job is worth by some heavy handed tactics.