Temporary crossings can be made from expanded metal gratings. Expanded
metal grating is a commercial product made from regular (not flattened)
nongalvanized steel. The grating is placed on top of nonwoven geotextile.

Where Used

Operators can use expanded metal grating crossings on shallow wetland or sandy soils. They also can be used on roads that don’t have high spots (e.g., stumps or large rocks) where grades are less than 4 percent. Because skidding causes the grating to move, this option is best limited to hauling and forwarding.

Application

Expanded metal grating crossings are usually built in sections that are about 4 feet by 10 feet. Operators install crossings by hand-placing the grating sections in each wheel path.

Expanded metal grating on geotextile

When installing an expanded metal grating crossing:

Size grating to meet expected loads, soil strength, and installation equipment. Use larger grating on very weak soils that have a low bearing strength. Prepare the surface by smoothing out high spots and filling ruts. Cover the entire crossing area with nonwoven geotextile. Lay the grating in the wheel paths so that vehicles drive on the long part of the grating.

Benefits:
Expanded metal grating is lightweight, durable, inexpensive, and provides some traction. No special equipment is needed to install the grating.

Disadvantages:

Grating tends to bend to conform to any ruts that may develop. Equipment may be needed to remove grating if it becomes covered by soil.