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Email: enquiries@kattenhornsurfacing.co.uk

Tarmac

L. A. Kattenhorn & Partners Limited specialise in all sorts of tarmac works.

It is a known fact that nearly all roads in this country are surfaced with tarmac. Tarmac offers good strength, durability and weather-resistance, ease of maintenance and repair, and neat, low-glare appearance providing good contrast to road-marking paint. This makes tarmac equally suitable as a surface for private drives, hard standings, car parks and parking areas for heavier vehicles and as a company we can takeout all works that involve this product. There is a wide variety of tarmac specifications to meet the broad range of their needs and use. We have been laying tarmac in the South since the company began.

We only ever use chosen suppliers who specialise in the production of asphalt. These suppliers include Yeoman Asphalt with whom we have been working since our company started, Hansons, Wainwrights and Tarmac. We chose our suppliers based on location in comparison with the site of works and on their performance. 

Drainage: Thanks to experience we will always try to provide suitable levels in order to ensure your drive or large area will drain properly avoiding the chance of puddling. We will ensure the area is dipped and create levels that will allow the water to flow to the suitable guttering or drain.

Subgrade: The subgrade should be shaped to the falls required for the finished surfacing to ensure that the overall construction is of uniform thickness. Before final shaping, any weak areas of soft clay, peat or soil should be excavated and replaced with more suitable fill or sub-base material. If the subgrade is to be exposed for some time and particularly if it is clay, the question of protecting it against ingress of water should be considered. Failure to provide this protection can lead to a seriously weakened subgrade if wet weather is experienced during the work.

Sub-base: The sub-base has two functions, one to provide a working platform for construction traffic and the other to increase the intrinsic strength of the construction. For parking areas which will carry only light vehicles there will be many situations in which a sub-base may not be needed. On clayey soils which become sticky and soft then they are wet it is usual to provide a sub-base of a minimum thickness of 75mm. A greater thickness will be needed with subgrades susceptible to frost damage, where ground conditions are poor or where the parking area is to be used by heavier vehicles than private cars.

The material should be spread, shaped and well compacted to provide an even surface to the required levels and falls.

Base and Surface construction

A selection of suitable tarmac materials for the construction of the base, binder course and surface course, together with recommended compacted thicknesses.

Table 2 the construction for a permeable surfacing.

Where tarmac is hand-spread in areas such as private drives and small car parks where the normal mechanical road paver is unable to operate more workable materials are necessary. If an appropriate binder is not used there is a serious risk of marking, particularly in early life, which will be aggravated by heavy braking, on-the-spot wheel-turning, and heavy point loadings especially in warm/hot weather.

Porous Asphalts are manufactured using either a penetration grade binder or for more onerous applications a Polymer Modified Bitumen. When hand laid, the resultant mixture requires suitable weather conditions and laying expertise to ensure it is spread and compacted to provide a resilient and durable surfacing.

Where a Porous Asphalt is to be used for larger areas and/or heavier usage car parks, advice on suitable mixtures should be sought from the asphalt supplier.

It should be borne in mind that off-road vehicles and the heavier types of car, e.g. people-carriers, may impose higher stresses on the surfacing than normal private cars as will on the spot turning using of power steering. Therefore the use of more specialist materials is required and advice should be sought from a professional contractor or direct from an asphalt supplier.

Surface course materials are available to give a coloured finish where required, although these are always very high in price.

            

Laying

Satisfactory performance of the construction will be obtained only if all layers are adequately compacted.

Compaction should be undertaken with a minimum six-tonne deadweight roller or an equivalent vibrating roller. The asphalt layers must be compacted while the material is at an appropriate temperature.

Recommendations for temperatures and for laying and accuracy of finish for asphalt construction materials are given in BS 5949879. For Porous Asphalt recommended temperatures for laying and compaction should be obtained from the material supplier.

In view of the skill needed in laying asphalt materials, particularly those required for the permeable surfacing option, it is strongly advised that laying be entrusted to experienced specialist surfacing contractors for example members of Mineral Products Association or their sub-contractors.