7.6 Construct the Tread Stake the trail route from start to finish. Stake the centre-line for minimum standard trails and both sides of the trail for higher standard trails. Place the stakes to define the trailbed and clearing limits. Before full excavation and construction take place, clear and excavate a narrow work path from the outside stake towards the centre-line. This path establishes the grade and excavation line for the rest of the trailbed. If alterations are needed, less time and damage is done than if the entire trail width is graded. Grade the trail bed on slopes as required. On slopes, remove leaf litter and surface soil material from the cut-and-fill areas and save for later use. Select an angle for cut and fill slopes based on local soil conditions, amount of rainfall and plant cover. Ideally, retain cut and fill slopes at less than 1:1. Spread topsoil and organic material on large embankments susceptible to erosion to encourage vegetation regeneration. On very steep slopes, use netting material, such as jute mesh or chicken wire held in place with stakes, to hold the topsoil and mulch in place. Round out the top of embankment shoulders to prevent soil from sliding onto the trail. Remove boulders, logs and other debris that may fall onto the trail. Avoid disturbing plants at the top of the cut slopes and at the base of embankments. Trim exposed roots flush with the soil surface. Pitch the trail tread at 1.5-3% toward the outside edge to allow for drainage. Make the tread slightly wider in areas where sloughing of the trail edge is likely to occur. On talus or rubble where little or no soil is present, construct the outside part of the trail with handplaced rocks, 50% of which are 30 cm in diameter or greater. Build the outside bench from rock other than those forming the inside bench. Fill all voids in and under the trailbed surface with rock and mineral soil deep enough to provide a firm tread. Where soils are not excessively mucky, use a layer of small branches as a trail base. Branches with dense growths of lateral twigs, are most suitable, e.g. fir and spruce. Lay out branches in a criss-cross pattern to form a mat. Use mattocks wherever necessary to carve out the slope by pulling the earth down onto the previously placed branches and trees, and achieving the same shelf-like effect. For narrow wilderness trails on extremely steep slopes, wedge a log parallel to the edge of the trail, against two standing trees. Fill the gap between the log and slope with small branches, rocks and earth to achieve a "shelf" for the trail. Consider commercial products for use in fine textured or wet soil areas: Mirafi 140 (Celanese Canada), Typar (Dupont) and Lotrak (Low Brothers). These are thin sheets of synthetic fabrics which allow passage of water, yet separate surfacing materials from underlying soils. These barriers increase the bearing capabilities of surfacing, because there is a greater lateral dispersion of load and pressure. Bear in mind that fabrics may become exposed after heavy use, resulting in maintenance costs.