What Is The Difference between Tarmac, Asphalt and Bitumen?
Asphalt, bitumen and tarmac, the three most popular road surfacing materials are indeed quite difficult to tell apart at first glance. However, the nature of these three materials vary drastically, so it is important that you understand their characteristics before you decide on the best surface for your road, driveway or parking area.
Bitumen describes a naturally occurring material (referred to as tar or “crude bitumen”) as well as man-made by-product of petrochemical industry. The streets of Baghdad were paved with tar as far back as 8th century AD. It was also used as seal for roofing shingles and to seal the hulls of ships and boats. Bitumen is normally black. Bitumen or tar is 100% recyclable and thereby environmentally friendly. Tar is susceptible to temperature changes. It becomes brittle in cold weather and very soft in hot weather.
Asphalt, in its liquid form sometimes also referred to as tar, is produced in a plant that heats bitumen and mixes it with aggregate (sand, gravel etc.) into a composite mix sometimes referred to as asphalt concrete. Asphalt results in a smoother and more durable surface than a bitumen-sealed road. Asphalt is mainly used for the paving of road surfaces, car parks, tennis courts and play areas. Asphalt surfaces have a better durability and resistance to weathering than tars. Asphalt is generally a bit more expensive than tar.
Tarmac, short for tarmacadam, is a road surface paving material that was patented in 1901 by Edgar Purnell Hooley. It is a mixture of tar, modified with small amounts of Portland cement, pitch and resin which is mixed mechanically and heated before laying it down. The mixture is then covered with gravel or stone chips and then compacted with a steamroller.
Q: Is power-washing safe on all roofs? I was told that power-washing may cause damage to the roof, especially when combined with unnecessary foot traffic often leading to cracked or broken roof tiles.
A: Pressure cleaning a roof, when done properly, is safe, cost effective, and will not force water through or under tiles, as the jet angle is controlled and always points away and down the roof, rather than into it.
Q: What sealer do you use to waterproof the roof?
A: We use an approved rubber sealer. The sealant is a rapid curing waterproof and anti-skid roof coating that cures within 20 minutes and can withstand temperatures down to -30°C*. It sets as a fully bonded membrane with over 200% elasticity. It is available in seven colours as standard.
Q: What if on initial inspection you notice that the roof is damaged. Do you still apply the sealer or I have to have the roof fixed first?
A: When we inspect the condition of the roof prior to undertaking the work, we make note of any potential weak spots in the roof or obvious damage. We then give you an option to repair it using your own contractor or our highly experienced roofing contractors can fix it for you. We can repair any type of roof – tiles, slate, shingles, corrugated iron etc.