California Department of Transportation

Roadside Management Toolbox

Rubber Weed Mat

Rubber Mat Under Guardrail Rubbermat Detail
Rubber Weed Mat Rubber Weed mat

What is this treatment?

Rubber mats are an adopted technology from the recreation industry where they were used primarily for playground safety surfacing. As with most structural treatments, the tiles prevent sunlight from reaching the ground surface, retarding seed germination and plant growth. The major component is recycled tire rubber bonded together with a resin into a mat. Cut outs are molded or cut into the tile for post placement. The inherent weight of the tiles keep them in place, no staking is usually required. Mats are joined together with an overlap that is sealed with an asphalt crack filler or resin adhesive.

This Powerpoint Presentation on Rubber Weed Mat helps illustrate some key points regarding design and installation.

When to use this design concept?

Use this product in urban, suburban or transitional areas under new and existing guardrail, around sign posts and under fences. Rubber mats are not recommended for large, non-linear areas or slopes.


  • The treatment is installed in sections and can be placed or repaired with no specialized equipment.
  • Due to the weight of the mats, no staking is necessary.
  • Since the product is flexible and not adhered or staked to the ground surface repairs after a hit are more easily accomplished than with other surface treatments.
  • The manufacturing process allows for specialized design for site specific requirements.
  • Integral color can be added in the manufacturing process.


  • Multiple joints in continuous runs may become unsightly over time.
  • Installation can be slow and labor expenses may be cost prohibitive for small installations.
  • Exposure to high winds, or disturbance by mowing equipment may displace or lift mats, allowing weed growth.
  • Joints have the potential for separation and vegetation growth if not sealed properly.
  • Weeds may germinate on the surface of mats if not kept clean of debris.
  • Long term degradation of the mats due to UV light and other factors is unknown at this time.

Specifications and Details

Nonstandard specifications and details are available from the Caltrans Intranet at the following address:

If you are NOT a Caltrans employee, and you need these specifications and details for consultant design work, please contact your District Landscape Architect to get a copy of these files.


  • $20 - $45/yd2
  • BEES Item(s) - none


Updated: June 1, 2015