The type of surface treatment chosen for a path will depend on many factors. These include availability of materials and labour, the type of ground conditions and slope, drainage, access, local traditions and personal preferences.
A description is given below of the range of treatments which tend to be used for different types of areas. This is not intended as a guide, but only as a broad overview of the range of techniques available, which are discussed in detail later in the chapter. In Britain, techniques tend to be developed by different managing authorities to suit their own conditions and budgets, and once found to be successful, are kept to. This helps reinforce the character of particular areas, but does not preclude the exchange of ideas and techniques between different areas.
In lowland areas, where grass paths are not sustainable due to heavy trampling, some sort of loose stone aggregate laid over a base of larger stone would be the usual solution. Access by vehicle is usually possible so use of bulky materials is not a problem. On permanently wet soils, boardwalks can be constructed (see Chapter 9 – Boardwalks and bridges), and in a lowland setting, are not visually intrusive. Raft or floating paths of aggregate over geotextile can also be used for mineral soils prone to waterlogging. Mortared stone paths or concrete paths may be appropriate for riverside paths. Woodchip surfaces are suitable for woodland paths on well drained soil.
In upland areas, transport of bulky materials may be a problem, and the use of artificial materials is usually avoided for aesthetic reasons. Timber may also be considered to be intrusive above the existing tree line, and is not sufficiently durable in the extremes of climate. Stone is the obvious material. Some areas are fortunate enough to have sufficient supplies of pitching-size stone on the hillsides to build paths; in other areas stone will have to be brought in, either as pitching stone, flag stones, or loose stone for aggregate paths. On the steep and rocky slopes of the Lake District, North Wales and elsewhere, stone from the hillside is used for pitching on slopes of between about 10 and 20 degrees, as well as being used for drains and culverts. No other materials are necessary. In other upland areas such as the Yorkshire Dales, use is made of the subsoil technique which requires no imported material.
The use of helicopter airlifts to transport stone to inaccessible sites is becoming much more common, and is proving to be cost-effective. Compared with using dumpers or other vehicles, a helicopter airlift is fast, does not damage the ground, and avoids both having to build the new section of path strong enough to carry a vehicle, or upgrading access from the nearest road to the worksite. Flagstones are lifted in bundles, pitching stone in bags, and aggregate in hoppers. About a ton is moved in one lift from roadside supply to path, with turnaround times of under two minutes being usual. Aggregate can be spread direct onto the path base, allowing half a kilometre of path to be laid in one day.
Large areas of the uplands have fragile peat soils, which are rapidly damaged by trampling. Thick peat soils are the most difficult areas for path management, and over the years, many techniques have been tried. The preferred options are floating stone flag or ‘causey’ paths, or raft paths of stone aggregate over geotextile.
Whilst artificial materials such as geotextiles still have their uses on some sites, the trend in the uplands is towards the skilful and sensitive use of local materials, combined with long-term management of path networks. The labour input varies tremendously with the type of technique. Stone pitching is very labour-intensive, whereas the laying of flagstone paths and subsoiling are highly mechanised, requiring the use of helicopters and excavators respectively. Investment is being made in construction methods which will be durable for many years, with minimal maintenance. Once on site, stones for pitched and flagstone paths are there for ever, and can be repositioned and re-used as necessary. Stone aggregate paths on slopes easily erode, and the material cannot be retrieved and re-used.
In Scotland, Pathcraft Ltd. have developed the skills and experience to build very natural-looking, high quality paths using only natural materials. For approach routes to mountains, typically paths of about 15 degrees or less on eroded peat, any surfacing material needed is dug from nearby borrow pits. With stone cross drains, and sensitive landscaping of path edges, the result is a path that most walkers instinctively follow, whilst hardly being aware of the work that’s been done. Such paths are expensive in labour, but give a high quality result, as well as much needed employment in rural areas. At the other end of the working spectrum, an excavator and driver could complete in a week a length of path that might take six people weeks to hand-build, but the result may not be a path appropriate to an upland landscape.
Rocky coastal areas have similarities to uplands, with steep slopes, extreme exposure, limited access for machinery, and a need for sensitive treatment of wild landscapes. Aggregate surfacing is used, with stone pitching a suitable technique for steep slopes. Beach stone is too rounded for path use, and usually stone supplies have to be brought in. Sand dune management may require the use of special techniques, including boardwalks and temporary surfacing such as straw. For further information see Sand Dunes.
A sward of grass and short herbs is of course the natural and best walking surface, with many species adapted to thrive under a certain degree of trampling. A springy grassy turf, sustained by grazing and trampling, is the ideal surface which is attainable over most parts of lowland Britain, and where slope and soils allow, in the uplands. Techniques to encourage and restore grass surfaces are discussed in Chapter 11 – Erosion control and vegetation restoration. Stone aggregate paths and pitched stone paths can be seeded to produce a durable, partly grassed walking surface.
