Spencer and Associates have been doing Driveways and Carparks in the Sydney Area and particularly the North Shore for the past 40 years.
This is a guide to advantages and disadvantages of using Hot Mix Asphalt, known also as Bitumen, Concrete inc Coloured Concrete, Pattern Concrete and Stamped Concrete, Decomposed Granite, Pavers and Two Coat Gravel Driveways.
Hot Mix Asphalt
Also known as Asphaltic Concrete or Bitumen. This is a mixture of Bitumen, a by-product of petroleum, with sand and gravel. It is mixed to a temperature of about 170 Deg. It is laid very hot and so then at air temperature it is hard and can be driven on straight away. It gets laid on a very solid well compacted base.
- Work carried out quick and no delay in being able to walk and drive on it.
- Cracks caused by tree roots don’t look bad. If ground rises due to roots, it is a long time before it becomes a trip hazard as it bends as it lifts.
- Cheaper than concrete.
- Has a non-descript grey appearance. People notice the house and garden and not the driveway. Hence it is very popular on expensive homes.
- Leaves actually look neat on it as it gives a country lane look.
- Lasts for 20 years and is cheap to do a recoat then.
- Easy to do a patch if say a plumber puts a trench across it.
- Petrol will dissolve it. Fill mowers away from it.
- Soft for first few months so have car rolling when doing sharp turns as it can scuff.
Two Coat Gravel Driveways
Has a road base put down first. Then a sprayed layer of Bitumen that comes out like black paint. Then one thin layer of coloured stone. Another spray of Bitumen creating a sand paper effect. Then top layer of coloured stone. Easy to walk and drive on if you chose a smaller stone about 7 to 10mm.
- Looks great particularly if you chose the right colour gravel to match the house. Lends itself to a brick or stone edge around it.
- It is loose on the surface so can wash downhill if on a steep incline.
- Needs a rake over now and again to level up and remove leaves.
A road base is put down first then a layer of Decomposed Granite that has a cement content in it.
- Looks great.
- Looks good in photos.
- Quickly done.
- Not expensive
- Sticks to your feet when wet.
- Is dusty when dry.
Normally 100 mm thick on top of compacted road base. Normally 25 mpa strength and F72 mesh.
- Solid and easy to clean.
- Lasts 20 years.
- White really stands out and is the dominant thing you see.
- Coloured Concrete fades and needs yearly sealing.
- Patterned Concrete often called Faux Crete and Stamped Concrete was very popular in the 1980s and 90s. So now it dates a house.
- If tree roots crack it then quickly becomes a trip hazard.
- After 20 years it has to be totally removed and start again. Not like hot mix that just gets a topping put over it.
A solid base then a thin layer of bedding sand to set pavers in.
- Looks great when a job is done well with a good pattern and border.
- Pavers move when on turns in high traffic areas.
- Often hard to match in years to come when cracked ones need replacing.
- Oil stains look bad.
- Can get grass growing between them.