Tarmac2016-12-08T19:02:40+00:00

Our expertise installing tarmac driveways has been developed over many years and we have extensive experience and highly skilled staff that allows us to undertake tarmac works of any size.

The installation of tarmac especially in a residential setting where most work involves hand laying requires specialist skills and equipment and you can be confident that Colordrives has both.

When laying tarmac driveways we adhere to EN regulations for the installation and preparation of a new driveway ensuring that it will be durable and stand the test of time.

Some driveways can be resurfaced otherwise know as an “overlay”, this is a cost effective way of surfacing a driveway where the existing tarmac is suitable, more information can be found here.

How We Do Tarmac Driveways

Step 1 – Excavation

Once we have agreed the shape of your new driveway, the first job is to excavate down to formation level the existing driveway and  any areas that the proposed driveway is to be extended into.

All our driveways are excavated to a depth of 230mm (9″), this is to allow for the 3 layers that make up a residential driveway. In cases where there is an existing driveway our quotation will specify the re-use of any suitable existing hardcore.

Layer 1 – MOT type 1 specification reclaimed hardcore to a depth of 150mm.
Layer 2 – 20mm dense graded base course tarmac to a depth of 50mm
Layer 3 – 125 PEN 6mm dense graded surface course SMA tarmac to a depth of 30mm

Tarmac driveway structure

It is essential that your new driveway is constructed in this way to ensure that it does not subside and that the surface course tarmac does not fail long before it should, you may find that other quotes you have had do not follow these specifications or specify a “one coat” method which will often explain differences in quoted prices.

In the photos above you can see how thin the 6mm surface tarmac has been laid, there is no base course tarmac at all, these driveways did not last as long as they should of if done properly.

All excavations from your site will be taken away by a licensed grab-away company, some of the excavations such as soil, tarmac and concrete will likely be recycled and any materials that cannot be recycled will be taken to a licensed tip.

Some driveways will require the use of a membrane at the formation level, this will sit between the sub-grade and the sub-base hardcore, this will only be required if the sub-grade is particularly poor ground and is designed to prevent migration of the sub-grade into the sub-base hardcore, If we think its necessary we will install this at no extra cost.

Once the hardcore has been installed it is levelled and then fully compacted using a heavy duty vibrating roller.

Step 2 – Edging Course

All tarmac surfaces should be retained by a solid edging course, if no edging course is installed over time the tarmac will crack and start to crumble, not only will this reduce the life of the driveway it will also be a haven for weeds growing in the cracks.

Tarmac failed edge

Many different forms of edging can be used but we most commonly use a clay or concrete paver’s or a KL or KS concrete edging kerb.

Once the edging course material has been selected they will be installed on a 100mm concrete bed and haunched to the front and back to prevent lateral movement.

In some cases where an edging kerb is raised we may gap each edging brick or kerb and mortar joint the gaps.

At this stage any other additional parts of the job will also be installed such as drainage, steps, recess manhole covers and block paved aprons.

 Step 3 – Sub-base Preparation

Once the edging courses have been installed additional hardcore will be spread, raked and compacted to bring the sub-base up to the correct levels for the installation of the sub-base tarmac course.

This will be hand laid to a depth of approx 50mm and fully compacted with a vibratory roller.  This layer of tarmac along with the hardcore is the real strength of the driveway and will help ensure it does not subside, not installing this layer will ultimately effect the longevity of the driveway.

Tarmac base course being laid

Step 3 – Laying The Surface Course

After the base course layer has been laid the final step is to lay the 6mm SMA (Stone Mastic Asphalt) surface course  layer. This is the decorative layer of tarmac that requires the most expertise to lay.

We only use the more expensive SMA surface course tarmac on our driveways as it is far superior to standard tarmac, being more resistant to power steering and general surface wear.

Tarmac surface course being laid

The surface course tarmac will be heavily compacted with a vibrating roller, while the edges and any areas where the roller cannot fit will be compacted using a hand rammer and a vibrating wacker plate.

Once this is complete the driveway is finished and will need to be left for anywhere from 2 to 6 days dependant on the weather for the tarmac to harden before vehicles can be parked on it.