Permeable Paving Installation - Western Interlock Western Interlock

Paving Stones and Retaining Wall Systems Made for the Northwest

Permeable Paving Installation

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Note: Geotextile is optional depending on the soil conditions, and is placed on the compacted soil sub-grade under the open graded base.

Apply geotextile to the bottom and sides of the excavated area. Start laying geotextile at the top end of the drainage slope following down with overlapping joints of 24″. Install all drain pipes, observation wells, overflow pipes in the base, depending on their location.

Place, grade and compact 2″ open aggregate for the sub base. The sub base is typically compacted to 6-8″ lifts with a minimum 10-ton static roller. Make at least four passes with a maximum of 4″ of aggregate per lift, with no visible movement in the sub base material when compaction is complete. Care must be taken not to damage the installed drain pipes during compaction and paving. Keep area where pavement is to be constructed free from sediment during entire job. Geotextile, base and bedding materials contaminated with sediment should be removed and replaced with clean materials.

After sub base is compacted, apply 4″ of ¾” open aggregate for the base material. Compact with the same process as the sub base material. The base is typically compacted with a minimum 10-ton static roller. Make at least four passes with no visible movement in the base material when compaction is complete. The elevation of the compacted surface should not deviate more than ± ½” over the length of a 10′ straightedge.

Screed 1-1½” of ¼” #10 aggregate as a leveling course. Do not compact this layer!

Lay the paving stones on the leveling course in the patterns recommended by the manufacturer. Maintain straight pattern lines; use string lines if necessary. Cut pavers with a double bladed splitter or masonry saw to fill gaps at the edges of the paved area. Compact and seat the pavers into the bedding material by using a low amplitude (75-90 Hz) plate compactor capable of at least 5000 lbs. centrifugal compaction force. During laying, all pavers within 3′ of the laying face must be left fully compacted at the end of each day.

Sweep ¼-#10 into the openings, vibrating and compacting the pavers again until the material is ½” from the top surface. This will require two or three passes with the compactor. Do not compact within 3′ of the unrestrained edge of the paving stones. Remove excess aggregate by sweeping pavers clean.66 Permeable Install

The final surface elevations should not deviate more than ± 3/8″ over the length of a 10′ straightedge. The final surface elevations should be 1/8 – 1/4″ above adjacent drainage inlets, concrete collars or channels.