Continuous paved surfaces for example, require roots to be managed downwards at least 1’-0” (300mm) to reduce the risk of pavement heave and other surface root damage.

  • Feeder roots are in the first 6 to 12” of soil.
  • Structural roots go 3’-0” to 15’-0” deep.

Root barriers provide a non-penetrable surface that forces roots to grown downwards, reducing the risk of damage to adjacent pavement. (Image from BlueGreen Urban)


  • Provide root barrier along critical root zone of tree at trail and other pavements, where critical root zone intersects with pavements, along the length of intersection. A 1’-0” deep ribbed, root barrier is required when trees are within 15’-0” of trail. Use ReRoot 300 by GreenBlue Urban, or approved equal.
  • When planting trees within paved areas, provide a continuous root barrier around tree well. Depending on the pavement area, a deeper root barrier may be required. Use RootDirector by GreenBlue Urban or approved equal.