Surface Types

Bituminous Surfacing Materials

There are several types of bituminous materials that can be used for roads, driveways, footpaths etc. Each has it's own specific quality for the use it is intended for; eg. drainage, wearing and or traction purposes among others. At StoneRoad Tarmac we survey each specific job and decide on the ideal material required. This will be explained to you by a member of our staff at the time of survey.

Newly laid tennis court

Basecourse Mixes

These materials are used to give a good firm surface on which to lay a wearing course material. They consist of a well graded large stone and dust mix which gives a good matrix. Held together by bitumen, this gives a well bound, dense material which is suitable for laying the wearing course on. It is essential for all asphalt wearing courses to have a Basecourse Macadam because of the density of asphalt that provides ultimate endurance against wearing. This eliminates the risk of fragmentation which may occur when you do not lay the correct basecourse.

It is not essential for all tarmac wearing course mixes, where a good stone foundation can also provide the base course required on certain jobs. For example: Household driveways, private roadways, play areas, tennis courts etc. This can be further explained at time of survey.

Completed carpark with parking spaces marked out

Wearing Course Mixes - Macadams

There are three main wearing course materials. 6mm, 10mm and 14mm, and all are used for specific jobs. Each mix can be individually tailored to your specific requirements, for example: where extra drainage is required an open texture can be specified which increases the amount of stone used in the mix. This will slightly reduce the durability of the surface but under some extremes may be necessary. The opposite of open texture would be dense texture where the specification would be to add in more fines, such as sand, stone dust etc. This creates a smoother more durable wearing surface than normal. Good all round drainage is essential in order to use this mix because it eliminates any water seepage.

Specification for 6mm wearing course:- This is a very fine mix which gives an excellent finish but does not have the strength required for heavy traffic and is therefore used mainly for footpaths, play areas and small household driveways etc.

Specification for 10mm and 14mm wearing course:- These mixes are the preferred mixes for heavy traffic areas with each material providing an excellent finish coat and both having the strength and durability to resist wear by heavy traffic. 10mm is a particularly good finishing material when extra fines and bitumen are added. This mix is known as bungalow mix, highly recommended for household driveways because of its neat finish and durability. We will determine the right mix on survey after we have ascertained the amount of traffic in the required area.

Asphalt road paving in progress

Wearing Course Mixes - Asphalt

Specification for hot rolled asphalt:- This material consists of a high sand content along with a specific amount of stone held together with enough bitumen to give a well bound mix. Asphalt is a very strong material and is also extremely durable. It is used mainly on very high traffic areas where the addition of chippings can be used to give good skid resistance. For example: Shopping centre car parks where there is a lot of twisting and turning and heavy load delivery vehicles, main motorways, airport runways etc. Designed for commercial use, not suitable where a neat finish is required.

Specification for Marshall Asphalt:- Marshall Asphalt is a US designed material also known as American asphalt. A cross between normal asphalt and macadam this mix combines sand and dust along with a high stone content to give the durability of asphalt and the managability of tarmac. When used correctly creates the smoothest most durable surface possible for all types of commercial and residential jobs. For example: Household driveways and small to medium size retail premises. This material is currently being used on the runways at Dublin Airport. Extremely suitable where a neat finish is required. Laid with the latest machinery and quality workmanship, you can be assured of the perfect finish.

Specification for SMA - Stone Mastic Asphalt:- A very durable mix which is also stable and resistant to deformation. A very high stone content gives excellent skid-resistance properties and also reduced noise levels. Surface water is also reduced due to the very high stone content which can be extremely useful on steep hills and level areas. The mix is strengthened by the addition of dust and a very high bitumen content held in the mix by the use of fibres. A very popular material which has been used in America for over 20 years and is becoming increasingly popular in Ireland and the U.K.

Additional information: It would be virtually impossible for us to list on paper all the types of tarmac and asphalt surfaces, there is endless variations of materials and mixes available. The most important thing is that you understand the basics and we hope we have provided you with a little insight to the way we at StoneRoad Tarmac take in choosing the right materials for your individual requirements. Remember the actual material and the way it is laid are the two most important factors when it comes to providing the perfect surface that you demand.

Tar & Chip

Tar & Chip finish on a laneway between houses

For a Tar & Chip finish hot tar is applied to a gravel base. Stone chips are thrown on top of the tar while it is still piping hot, so that they can stick to the tar. After the stone chips are laid on top of the tar, a steamroller is used to press them in firmly. The customer can choose from a variety of different stones and stone colors to achieve the look they want.

Below is a list of the sizes of materials generally used:

  • 6mm
  • 10mm
  • 12mm
  • 14mm
  • 20mm
  • 28mm

These are used in Marshall Asphalt, Stone Mastic Asphalt(SMA), Tarmacadam, Dense Macadam.