Sometimes a new driveway is needed up or down a very steep slope, to give access from the road to the house. In these cases the very best material to choose is tar seal, simply because it provides excellent grip in wet and dry weather and especially during a heavy frost. While most homeowners tend towards choosing a concrete solution, they should really avoid concrete for a very steep driveway because it is easy to lose traction in wet or frosty weather. In any case a sealed driveway is around the same cost as a concrete driveway, although it does require specialist preparation beforehand. It is important to hire a good quality concrete contractor for the task.
If the driveway is to be built on an unformed slope, then it will be necessary to get a bulldozer to make sure that the driveway is smooth and level across it at all points up the slope. If the driveway cuts into an existing Bank then the bank should be retained before the driveway is built, and this can be done using crib walling made out of concrete or ground treated timber. It could also be achieved using vertical half round logs that are square edged, and this can be preferable for the homeowner as it is relatively easy to do and the final finish can be very attractive and very long lasting.
Once the necessary retaining is in place and the driveway has been properly graded then concrete edging should be set. This will generally be 4 inches thick, and set to the final level of the driveway. Once the edging has been set and cured then the base course should be laid out and compacted. The ideal finish of the base course in preparation for the tarseal should be a very hard surface with protruding stones and chips, to provide good attachment for the tar seal on the very steep sloping driveway.
The ideal material for the base course is called lime stabilised base course, and for a steep driveway that ascends from the road this is laid out most easily by using a hired small dump truck. These can carry a half a ton up a steep hill relatively easy, and it is the ideal way to deliver the base course to all points in the steep driveway. The base course should be spread out before compacting should be roughly level with the top of the concrete edging. After the base course has been spread out then it should be firmly compact using a hired half ton vibrating roller. These rollers are self propelled and are fairly easy for one person to operate, and they are also fairly easy to steer so they can be guided right up to the edge of the concrete edging to provide a very good finish to the base course.
Once the base course has been compacted then it will set rather like concrete if the weather is dry enough. It can be an advantage to spray the sloping driveway with water so that the fine sand on the surface is washed down the driveway, leaving the stones locked into the base course but exposed on the surface. This will provide the absolutely ideal attachment for the new seal to be laid.
The final work will be completed by a specialist tar sealing Crew, and while they can looked like pretty hard individuals they will generally be very professional and very proud of their work. In this way the best concrete contractor Tauranga has ever seen will admire your handywork. The base course should have been compacted to around 1 inch below the level of the edging, and the layer of tar seal will be around 1 inch thick bringing it flush with the level of the edging.
The tar seal will dry and harden and cool very quickly, and can be used within a few hours of the driveway being laid. The homeowner will always be delighted with the finish, because their car tyres will never skid on this driveway, and the driveway will stay looking very tidy and undamaged for decades.