Screed Rails

Throughout the industry the more common name for this tool in the hardscapers tool chest is screed rail, but screed pipe is also very common.

The function of a screed rail is to serve as a fixed (but temporary) guide when leveling crushed aggregate stone and/or bedding sand in the preparation of the base for a retaining wall or brick paver patio.

The screed rails pictured at right are simply ten foot lengths of 1″ EMT conduit, available at any big box home store.  If you choose to use the same material for your screed rails, inspect each one to make sure it’s not curved or bent, as this will negatively impact your base preparation, which will in turn have negative consequences on the finished paver surface or retaining wall.

In the case of this 1″ EMT conduit, parallel lengths of pipe are packed into the crushed stone base at the necessary elevation, then small piles of crushed stone are placed between the pipe, where a screed board is used to spread those small piles into the low spaces between those pipe by pulling/scraping perpendicular to the screed rails, from one end to the other.

Many other materials are commonly used as screed rails, including 1×4’s and 2×4’s, different types of pipe, and even materials as large as railroad timbers.  The only real caveat in selecting a material to use as a screed guide is that you select one that is straight to begin with, but that also won’t bend or bow under the pressure of screeding and won’t deform if it gets wet (such as narrow lumber).