Advantages & Disadvantages of Tarmacadam

Of all the different types of surfacing which can be used for domestic driveways and patio areas (such as block paving, pattern imprinted concrete and concrete paving flags), tarmacadam is still considered by some homeowners as the poor relation and the least expensive option.

Laying bitmac is a skilled process and often requires expensive machinery to ensure that the surface is well compacted, flat and level. Large areas can be very economically installed but in most cases, similar equipment is required for a few square metres as is required for several hundred square metres. Consequently, the set-up costs of installing tarmacadam for a small driveway mean that the cost per square metre of a tarmacadam drive can vary enormously according to its size.

Also, since bitmac and the binder material in stone mastic asphalt are oil-based the price per ton of all tarmacadam products can be quite volatile. Steep increases in the price of oil over the last decade have resulted in tarmacadam driveways and patio areas losing some of their price competitiveness when compared to other forms of domestic surfacing.

Advantages & Disadvantages of Tarmacadam

When laid properly though, tarmacadam is a durable, reliable and smooth surface which is relatively easy to repair – though when patched the repair is not invisible.

Tarmac can however, degrade under Ultra Violet light causing the bitumen to go brittle, crack and eventually break up, causing pot holes. These are not only unsightly but also dangerous, causing potential trip hazards which can lead to insurance claims on surfaces in public areas.

Additionally, being oil-based, the bitumen can dissolve or melt when lighter oils such as diesel come into contact with the surface. Diesel spillages can spoil a tarmacadam driveway and although the contaminated area can be cut out and patched, the whole driveway will look much better if it is all resurfaced.

Advantages & Disadvantages of Tarmacadam

Another issue with tarmacadam surfaces is the growth of moss, algae and weeds. Moss and algae will form in shaded areas which do not often dry out, such as below overhanging trees and shrubs, and these can form into slippery surfaces.

Weed growth on and through a tarmacadam driveway cannot always be avoided and though some contractors will install a geo-textile material to act as a weed membrane, there is some doubt as to its effectiveness in this capacity. A properly specified and constructed driveway with adequate thicknesses of the correct materials well compacted, will do more to prevent weed growth than a membrane. In any case, weeds can always sprout from above sending their roots into the driveway surface. The best a homeowner can do in this situation is to remove the weeds as soon as they develop and apply a strong weed killer.

Advantages & Disadvantages of Tarmacadam

Sometimes the surface of the tarmacadam will have been pushed open slightly by the weeds and this will need to be tapped back down. The inherent flexibility of the oil-based bitumen binding the aggregate together, normally results in the surface healing itself where only minor damage has occurred.

Advantages & Disadvantages of Tarmacadam