How to Buy the Right Landscape Tie
Your home center may have several options when it comes to pressure treated lumber for landscaping. You should know a few basic facts about each before you buy.
3”x5”x8’ landscape ties (nominal measurement)
Most 3”x5”x8’ pressure treated landscape timbers (LSTs) originate as the center cants from plywood veneer peeling mills. Logs are kept wet to make peeling easier and the peeled cants arrive at the pressure treatment plant without benefit of kiln or air drying.
Lumber that is not dried before pressure treatment cannot be fully penetrated by the treatment solution during the treatment process. This will be reflected with a shorter term warranty—in the case of ProWood treated lumber, one year—than would have been otherwise offered by lumber that had the advantage of full preservative penetration.
These ties are not recommended for applications that call for in-ground, structural performance over several years, such as fence posts.
4x4 and 6x6 timbers (nominal measurements)
ProWood timbers carry either a lifetime limited warranty or a one year warranty, depending on their intended end use. The surest way to know the difference between a timber made for landscaping and a timber made for a structural application is by the warranty.
If the timber carries a lifetime limited warranty it means it was dried before pressure treatment and can be warranted for structural use. Generally, these timbers are building code approved and carry an Evaluation Service Report from ICC-ES, a third party testing agency.
You can use timbers for fence posts, raised garden beds, retaining walls and any other projects that call for high performance over a long period of time.
Every piece of treated lumber in the store has an end tag, on which you should find the following:
Third party testing agency
Standard to which it is treated (ESR-2240 in ProWood’s case)
End use (ground contact or above ground, for instance)
Wood preservatives used (ProWood uses micronized copper azole)
Treating company’s name
Eco Friendly Products
ProWood treated wood products use the MicroPro treatment process which is certified under SCS's Environmentally Preferable Product (EPP) program. In addition to EPP status, the technology has earned Green Approved Product certification from the National Association of Home Builders (NAHB) Research Center.
Knowing the above information will help you make the informed choice when specifying your next outdoor landscape project.