Tarmac Driveway Installation – in 5 Steps
Whether it’s left over tarmacadam from the back of a truck for a resurface or a full installation from scratch using a professional tarmacadam contractor, below provides a rough tarmacadam drives installation guide.
Step 1 – Tarmac Driveways – Preparation
From the whole tarmac driveway installation process, the preparation stage is one of the most important. If you get the preparation right, you’re halfway there!
- Before any preparation work, it is advisable to have emergency contact numbers in case of disruption to utilities.
- Excavate the driveway area to appropriate ground depth (approx. 200mm).
- Use a licensed waste carrier
- Attention to levels! Adjust sub base levels to ensure appropriate water surface drainage. Adjust gradients to make a driveway less steep.
- Lay a sub base membrane for additional support and prevent weed growth.
- Lay type 1 sub-base aggregate (or recycled crushed concrete) to a depth of 150mm.
- Compact to a solid base of 110mm.
- Adjust manholes or utility boxes to the right levels.
- If surface drainage water is flowing towards a house install a soak-away and connect drainage channels. Alternatively, if levels allow, it may be possible to direct surface drainage water flows to grass or bedded areas.
A prepared sub base for a tarmac drive
Step 2 – Tarmac Driveways – Edging
Concrete edging provides support, therefore install concrete edging around the perimeter of the driveway. You can use a string line and level as a guide. As a minimum it is usually necessary to lay paving edging stones across the front of a driveway where it meets with the public pathway. This provides a clear line for the border of a property and ensures a flush finish.
Step 3 – Tarmac Driveways – First layer binder course
Lay the first surface layer, known as the ‘binder course’ (this contains a larger stone/aggregate). The binder course provides a strong base for the surface layer. Keep the hot binder course covered to retain heat. Place piles of binder around and rake to correct levels.
Once driveway surface is covered, roller as many times as necessary until the surface is compact.
Step 4 – Tarmacadam Driveways- Surface course
Lay the surface course in the same way as the binder course. The only difference is the size of the aggregate in the surface course compared to the binder course. It is much smaller and leaves a much smoother finish. Before it is applied, it may be treated with sealing grit, as this helps with the finer aggregate sticking to the binding agent.
Step 5 – Tarmacadam Drives – Finishing touches
Tar edges that join other surfaces to help prevent water ingress and stop weed growth.
Tarmacadam Drives Installation (Resurfacing option)
This is the most common type of tarmac driveway installations for residential driveways. A tired and/or faded looking concrete driveway can look ‘good again‘ and resurfacing is by far the most effective method. Preparation is minimal as long as existing drainage is sufficient. If not drainage should be a priority. Fill any holes and remove loose areas. Refill with suitable sub-base material such as Type 1 aggregate. The surface layer can be applied in the same way as outlined in the new installation process above.
Achieve significant cost savings by avoiding the installation of a new sub base!
What’s the difference between tarmac driveways and asphalt driveways?
Tarmac and asphalt are very similar, and both surfacing products are used for roads and driveways. Tarmacadam (tarmac) is created by mixing a layer of crushed stone with tar. While Asphalt is created by replacing the tar with Bitumen which is a by product of the oil industry.
Is a tarmac driveway expensive?
The cost of a tarmac driveway is roughly £65 per m². This makes it one of the cheaper driveway surface options, with gravel and some concrete block paving being cheaper.
Is tarmac cheaper than block paving?
Tarmac is cheaper than most block paving options, especially the modern blocks used for driveways. For most block paving driveways you can expect to pay towards the £100 per m² range compared to around £65 for tarmac. The only way to make a block paving driveway cheaper than a tarmac driveway is by installing the driveway yourself or possibly by using very cheap concrete blocks
How thick is a tarmac driveway?
The layer of tarmac on your driveway should be between 2 and 3 inches. A smaller aggregate is used in driveways compared to road surfaces to create a smoother finish. While this is less strong than the road version, it is still more than strong enough for you to park your car on for many years.
Can you tarmac over concrete?
Yes you can. However the better the concrete is, the better the end result. It’s therefore important to fill in any cracks and potholes on the concrete before adding the tarmac. However, the great thing about tarmac is that you can create a flat surface over almost any sub base.
How long does cold lay tarmac take to harden?
Why do you water tarmac?
On hot summer days, your tarmac driveway can become soft due to the heat. In order to harden the surface, you can run cold water over the driveway. This will cool it down and will stop melting it. You don’t have to run water over the driveway continuously. Just a spray overy so often will help cool it down.