How to Build a Retaining Wall

Your resource on how to build or construct a residential retaining wall


Things to consider in regards to building or constructing a retaining wall.

Tools
Height considerations
Slope
Obstruction
Costs

Small residential retaining walls can be constructed by the do-it-yourselfer (DIY), but larger commercial and more complicated walls will need engineering and one should seriously consider hiring a professional contractor.

Below is a brief outline of the steps needed to build a retaining wall.

How to Build a Retaining Wall
Planning and Layout
- Where to put wall
- Slope of area
- Height and Length
- Obstruction
- Water drainage
- Engineering
- Building Permits
- Miss Utility

Excavating
- Stake out wall
- Dig Trench for leveling pad and excavate for the reinforced area
- Leveling pad is a minimum 24" wide and 6" deep
- Add foundation stone
- Level and compact stone

Excavate foundation for the retainging wall Excavated trench with leveled anc compacted foundation stone
Lay first (base) course
-This is the most critical step
- Begin at lowest point of wall
- Lay block
- The base course should be below grade (buried)
- Level block - side to side and front to back
- Check alignment and placement

Leveling the base course for the retaining wall Leveling the base course for the retaining wall Filling block with gravel and removing excess for next course
Backfill
- Fill cores with stone
- Backfill one foot behind wall with stone
- Backfill excavated area with compactible soil
- Compact stone and soil
- Check for level and alignment
- Sweep excess material from top for next course

Drainage
- Place drainage pipe at the lowest possible level, usually at the finished grade level
- The drainage column should be a minimum of 12" behind blocks
- Drainage aggregate should be 3/4" to 1" crushed stone without fines
- Drainage outlets should be placed about 50 feet apart and no more than 75 feet apart

Laying the draintile for the retaining wall Drain pipe extending through retaining wall drainage column for retaining wall
Adding additional courses
- Lay blocks while maintaining a running bond
- Check level
- Run a string line
- Backfill 12" stone
- Remainder compactible soil
- Compact soil and stone
- Place geogrid
-Note: if using larger equipment stay three to four feet from block

Adding next course of block String Lining Blocks Compacting backfill for retaining wall
Reinforcement (if required)
- Cut geogrid to required length
- Geogrid is manufactured in various strenths, consult the engineered designs
- SF35, SF55 are two strengths
Geogrid for retaining wall Roll of SF55 geogrid
Finishing the Wall, fine grading and planting
- Cap wall
- Use six inches of low permeable soil on top of drainage column
- Plant landscape shrubs as desired


Always call Miss Utility at
811
before you start to dig!
Remember to dig with C.A.R.E.

Call before you dig
Allow the time for marking
Respect the marks
Excavate carefully


Copyright © 2008-2010 Bract Retaining Walls and Excavating, LLC - All Rights Reserved
Revised 7 October 2009 crt