BY ANDREW LAVALLEE, FASLA
Pavement and planting beds can play nicely?but it takes thought.
FROM THE JANUARY 2018 ISSUE OF LANDSCAPE ARCHITECTURE MAGAZINE.
It is a classic landscape architecture problem: placing pavements next to lawn or planting bed areas. The commonplace nature of this situation belies its complexity, an adjacency that represents an interface between two systems with antithetical requirements. In this case, the edge between pavement and planting bed is an area where an engineered structural system abuts a living horticultural system. Successful design solutions frequently require landscape architects to reconcile competing interests, but it is not always easy, given the demands of a project. In SiteWorks?s practice, we see the pavement?planting edge as a challenge for both designers and contractors alike. The edge merits special attention with regard to how we design and document the condition, how it?s built, and how its thoughtful assembly can benefit long-term performance. The Basics

Let?s start with what a successful pavement system needs. The structural support of a pavement relies on the strength and stability of the base course and supporting subgrade. A firm subgrade is typically achieved by removing organic content and densifying or compacting the subgrade to 95 percent density to ensure that it is unyielding under the weight of the paving assembly (dead load) and the assumed traffic (live load). The base course, usually a densely compacted granu...