Specifications

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At present there are no standard specifications for paths as there is for roads and pavements. The practice has been to provide 'bespoke' specifications for every path construction project, based on guidance from good practice resources like this Guide.

Clear and concise specifications are essential to inform those who are to construct the path and any related features, of exactly what is required. They should describe the quality of workmanship and materials for the construction work which will assist the tendering Contractors or Principal Contractors estimator to price the bill of quantities.

It is essential to cover everything that is required to build the path and any related features. Do not leave anything out, if something is not specified, it will not be built or installed. The following is a checklist of what should be included in a specification for a new build path:

Formation layer (including separation and reinforcement layers)
Excavation width and depth of formation tray
Working practices: what type of formation tray is to be excavated; what is to be done with the vegetation and excavated spoil generated from formation layer work; what is to be done with soft spots encountered in the formation level (bottom of the tray)
If required, type and grade of geotextile sheet to be installed in the formation tray
If required, type and grade of geogrid to be installed on top of geotextile sheet in the formation tray
Base layer
Type of granular sub base materials to be used to build the base layer and BS EN quality standards
Maximum depth of granular sub base material to be laid in formation tray
Maximum or minimum cross fall or camber gradient for base layer
Type and weight of vibrating roller to be used to compact the base layer and state ‘compact thoroughly to refusal’
Surface regularity of finished base layer
Surface layer
Type of surface material to be used to build the surface layer and BS EN quality standards
Maximum depth of surface material to be laid on top of base layer
Method of surface material laying
Maximum or minimum cross fall or camber gradient for surface layer
Type and weight of vibrating roller to be used to compact the surface layer and state ‘compact thoroughly to refusal’
Surface regularity of finished surface layer
Path verges
Path edges to be supported with available topsoil or suitable turfs won from formation layer works
Base layer material and geotextile sheet to not be exposed along edges of path
Landscaped verges to taper down and away from finished surface layer
Landscaped verge edges to be finished level with, or below, surface layer
Landscaped verge materials should not prevent surface water runoff from finished surface layer
Drainage features
Type of drainage features to be used
Type, dimensions and gradients for open ditches
Type, dimensions, gradients and materials for closed drains (french drains, filter drains)
Type, dimensions, gradients and materials for cut-off drains and piped culverts
BS EN quality standards for materials

 

The level of detail will depend on the extent and complexity of the path construction project. For small projects, written detail can be given in a simplified format.

Sample specification for a whin dust path
Excavate ground to reduced depth of 150mm below finished path surface level to form 1.5metre wide formation tray. All excavated material to be casted and landscaped into surrounding areas
Excavate any soft spots in sub-grade as required and backfill to formation level with well compacted 50mm crusher run
Supply and install Terram 1000 geotextile sheet in formation tray bottom and sides. Overlap adjoining sheets by 1.0 metre
Supply, lay and compact to refusal 150mm depth of DTp Type 1 granular sub base to falls and levels
Supply, lay and compact to refusal 25mm depth of 6mm whinstone dust to falls and levels
Where required, landscape verges level with finished surface layer to support path edge using suitable excavated topsoil won from formation layer works
All granular sub base materials to comply with SHW Clause 803

 

For medium or large scale projects, where there is greater risk to the Client if something goes wrong, more detailed written descriptions should be considered and included with construction drawings. Examples of specification details for various path surface types are provided below:

Unbound surface

icon As Dug Path - Standard Detail Drawing & Specification Details

icon Whin Dust Path - Standard Detail Drawing & Specification Details

icon Granite Dust Path - Standard Detail Drawing & Specification Details

Semi-bound surface

icon Toptrec Path - Standard Detail Drawing & Specification Details

Bound surface

icon Dense Bitumen Macadam (DBM) Path - Standard Detail Drawing & Specification Details

icon Hot Rolled Asphalt Path - Standard Detail Drawing & Specification Details

icon Surface Dressed Path - Standard Detail Drawing & Specification Details

icon Bound Gravel Path - Standard Detail Drawing & Specification Details

Porous surface

icon Reinforced Grass Path - Standard Detail Drawing & Specification Details

icon Reinforced Gravel Path - Standard Detail Drawing & Specification Details

 

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© 2014 Paths for All - Registered Scottish Charity No: SC025535, Company Limited by Guarantee No: 168554 inc. 19 Sept 1996 at Companies House, Edinburgh