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Compare & Choose Root Barriers

 


 

PANEL CONFIGURATION

 

We recommend that with a barrier depth of 24 inches, four (4) panels should be used for a 15 gallon tree. Planter size allowed 3" to 4" clearance between root ball and planter, DO NOT USE FEWER PANELS

 

 
  • 12" Panels are packed 40 per carton.

  • 18" Panels are packed 20 per carton.

  • 24" Panels are packed 20 per carton.
     

 


CHOOSING THE RIGHT PLASTIC

 

A U S Department of Forestry study (Oct 1,1993) reported the following:

Important in selecting a barrier is the material it is made of and various design features, notably the way in which either the panels or the ends of continuous barriers are connected together. Panels may be joined together with interlocking couplings, separate connectors or locking strips, or by use of chemical bonding agents (fig. 1). As indicated in Table 1, the panels may be made of polyethylene, polypropylene, or polystyrene. Among these three thermoplastics, polyethylene in the high density formulation is recognized in the plastics industry as most resilient and durable. By comparison, polypropylene is slightly harder and therefore eventually may chip or crack easier. Polystyrene, on the other hand, crystallizes readily in the presence of sunlight, in which case its durability is compromised." Polystyrene barriers are typically offered in a 'roll' format with glued on ribs. The rolls require assembly with a chemical bonding agent.

The following general characteristics may be corroborated by reference to any technical text.

 

 

POLYETHYLENE:

A tough but flexible thermoplastic exhibiting stable characteristics through a range of temperatures from -76 to +930 C. Polyethylene is not affected by the presence of moisture and makes an effective vapor or water barrier. It also resists degradation by any chemicals likely to be present in soil.

U.S. Forestry Dept. concludes: Polyethylene is recognized in the plastics industry as most resilient and durable.

 

 

POLYSTYRENE:

FOR INDOOR USE ONLY: A hard rigid thermoplastic exhibiting stable characteristics through temperatures from -30 to + 1 600 C. Although they have a good resistance to indoor environments, polystyrenes are not recommended for outdoor exposure. Continuous long term exposure to the environment results in degradation and reduction of strength.

 

U.S. Forestry Dept. concludes: We have seen polystyrene barriers begin breaking and crumbling within 1 to 2 years due to its tendency to crystallize and become brittle when exposed to sunlight.

 

POLYPROPYLENE:

A strong rigid thermoplastic with poor impact strength below 150 F ( 9.50 C). Polypropylene should not be used where extremely low temperatures are expected. The rigidity of polypropylene panels may require the incorporation of additional features to attempt to prevent panels lifting as roots pass underneath. (The efficacy of current design solutions to this problem are questioned in the Department of Forestry report) U.S. Forestry Dept. concludes: Polypropylene is slightly harder (than polyethylene) and therefore eventually may chip or crack easier. "Anti-lift pad" may actually have a reverse effect.

* * "ROOT SOLUTIONS" is the only manufacturer in the United States capable of producing a standard two foot root barrier panel in one piece from polyethylene.

 
 


CHEMICAL, CLOTH & MESH vs. ROOT SOLUTIONS

 

COMPARISON


 

ROOT SOLUTIONS

CHEMICAL, CLOTH or MESH

Root redirecting

Root nurturing guides redirect young roots downwards, finely anchoring the tree.

Chemical cloth barriers stunt root growth on contact. Any barrier without root directing features may lead to harmful root growth parallel to the barrier. (girdling).


Root nurturing

Patented design root guides harbor oxygen and moisture to feed redirected roots and encourage deep and healthy rooting.


NO nurturing or redirecting features.

Installation

Flexible panels connect easily with integral patented design quick connection. No third locking strip, glue, protective clothing, special skills or licenses required.

Some products may require protective gloves and clothing and a herbicide license from the state. Cloth barriers must be carefully pegged o r nailed up to prevent collapsing when back filling.


Surround Application

Root guides direct roots downwards to anchor trees and avoid ROOT GIRDLING.

In any barrier without root guiding features, including fabric barriers,

roots tend to grow parallel to the barrier

ROOT GIRDLING!


Cost

Re-cycled extruded polyethylene sheets EXTREMELY ECONOMICAL

Usually much more expensive than ROOT SOLUTIONS. Sometimes double the cost.


Life

15 years plus

Variable, depending on the fabric and the Manufacturer.


Best Use

New tree planting, protection of street- scapes, medians, swales areas, and root pruning.

Wrapping underground utilities or in horizontal applications.

 
 


HAZARDS OF POLYPROPYLENE ROOT BARRIERS

 

Reinforced top edge:

In an attempt to address root overgrowth, protect rigid panels from splitting and produce a more aesthetically pleasing installation, some manufacturers resorted to reinforcing or even double reinforcing the top edge of their panels.

 

While possibly aesthetically more pleasing on the architects desk, this `solution' has created more problems with the overall panel performance and safety than it has solved. This is particularly true where the panel has to conform to irregular shapes or in tree wells and surround applications.


The problem created:

Polypropylene is a relatively hard rigid and therefore brittle plastic most suitable for injection molding. Any molded product has a `mold memory', in other words an inbuilt predisposition to return to the shape in which it was molded. When a polypropylene panel is bent to facilitate a tree well, a force or tension is produced as it tries to return to its original shape. If this is true of the body of the panel, it is even more true for the extra mass of the reinforced top edge which is being bent across its axis. There is therefore a differential of forces concentrated along the joint between the top and the panel body. If an extreme bending of the panel is required, it may in fact snap altogether, but a more likely result is that the installation will be completed with the distorted panel body held firmly by the soil, while the top edge retains the tension which continues trying to break it free along the joint with the panel body.

 

While the body of the panel remains protected in relatively stable conditions underground, the top edge is subject to sunlight, large temperature swings, pedestrian traffic and the vagaries of maintenance procedures with the regular assault of grass cutters and weed whackers. The consequences of this abuse are inevitable. However strong the plastic, it will crack and degrade. The result has become a common sight on projects over a year old. The top edge will tear away and become a sharp projection and potential pedestrian hazard.

 

   

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