What is the minimum thickness of retaining wall footing?

Author: Shad Ebert  |  Last update: Wednesday, June 4, 2025

The thickness of a concrete retaining wall depends on the height and soil conditions, but typically ranges from 8 to 12 inches.

What is the minimum thickness of footing?

In reinforced and plain concrete footings, the thickness at the edge shall be not less than 150 mm for footings on soils.

How thick should a retaining wall base be?

Use crushed gravel with stones sized between 1/2 and 3/4 inch. The crushed fines from the gravel is what will allow you to compact it to a solid base. Your base depth should be 1 inch per 1 foot of wall height but no thinner then 4 inches thick. The base width should be twice and wide and the wall width.

What is the rule of thumb for retaining wall footings?

Rules of thumb commonly used by designers to establish the geometry of the wall include (refer to diagram): Base width = 1/2 to 1/3 of the height of the wall. Base thickness = 1/8 of the height of the wall but not less than 12 inches. Stem thickness = 6 inches + ¼ inch for each foot of wall height.

How thick of footing for retaining wall?

"Usually a first guess size for a cantilever retaining wall footing is about 40-60% of the wall height." For a standard cantilever retaining wall, that usually works, but for a toe wall, without a heel for the weight of the backfill soil to resist overturning, the footing may need to be much larger.

How to Calculate Loads on a Retaining Wall.

What is the minimum depth for wall footings?

The minimum depth of footings below the surface of undisturbed soil, compacted fill material or controlled low strength material (CLSM) shall be 12 inches (305 mm).

Can you build a retaining wall without a footing?

In summary, retaining walls do need a footing to ensure they are structurally sound and have proper drainage to prevent cracking or collapse. Without a footing, the ground beneath the retaining wall can shift, which can cause the wall to shift as well, leading to cracking or collapse.

What thickness of footings under columns or posts should be?

Footing thickness - 8 to 12 inches.

How deep should a footing be for a 8 foot block wall?

Always make the footing at least twice as deep as the thickness of the wall and twice as wide (Fig. 2). For example, if you are using 8" blocks, the footing should be at least 8" deep and about 16" wide.

What is the minimum thickness of a retaining wall?

For the Preliminary analysis, thickness of the base slab can be taken H/10 to H/15. H is the total ht of the retaining wall. Min thickness not less than 300 mm. Thickness assumed should be checked from bending moment and shear force requirement.

Does a 2 foot retaining wall need drainage?

Absolutely! Even a 2-foot retaining wall needs an effective drainage system. Without it, water can build up behind the wall, leading to pressure that might cause the wall to lean or even collapse. All walls need systems to manage water effectively, preventing damage over time.

What is the cheapest retaining wall to build?

Affordable Retaining Wall Options
  • Concrete Blocks. Concrete blocks are a low-cost option for constructing a retaining wall. ...
  • Railroad Ties. ...
  • Gabion Walls. ...
  • Timber Sleepers. ...
  • Retaining Wall Kits. ...
  • Natural Stone. ...
  • Terraced Gardens. ...
  • Pallets.

How thick and wide should a footing be?

A minimum of 12”inches deep for all footings and the width will be determined by the amount of stories, 12” inches for a single story, 15” inches for a two story and 23” inches for a three story.

How deep do footers need to be?

Depth of Footings

Footings should extend to a minimum depth of 12 inches below previously undisturbed soil. Footings must also extend at least 12 inches below the frost line (the depth to which the ground freezes in winter) or be frost-protected.

How to calculate footing size for a retaining wall?

The size of the wall will largely determine the size of the footing. For concrete, a poured concrete footing is the best. Block or brick walls should be a minimum of twice as wide as the planned wall. The footing of your retaining wall should be as thick as the wall's planned width.

What is the thickness of the wall footing?

Strip Wall Footings are constructed with typical slab depths between 6”-8” (15-20 cm), footing widths of 12”-24” (30-61 cm), and lengths that vary as needed. Strip Wall Footings are commonly paired with column widths of 6”, 8”, 10” (15, 20, 25 cm). What factors impact the strength of a building foundation?

How thick should a column footing be?

They are made not less than 1 1/2 times the projection of the slab beyond the face of the pier or column or the edge of the baseplate of a steel column. It should in no case be less than 150mm thick.

What should be the depth of footing?

All foundations shall extend to a depth of at least 50 cm below the natural ground level. The minimum depth of footing on sandy soil is 0.8 - 1 m, for rocky soil, it is 0.05 - 0.5 m and for clayey soil, it is 0.9 - 1.6 m. The minimum depth of foundation for the load-bearing wall is 900 mm.

How deep should a retaining wall footer be?

The footing, or first row of your retaining wall, should be about 4 to 6 inches deep and about 12 inches wide, or twice the width of the block you are using.

What are the 7 common mistakes made when installing retaining wall blocks?

7 Common Mistakes To Avoid When Installing a Retaining Wall
  • Choosing the Wrong Material. ...
  • Not Providing Adequate Drainage. ...
  • Forgetting the Frost Line. ...
  • Too Much Weight Behind the Wall. ...
  • Inadequate Footing. ...
  • DIYing a Complicated Wall. ...
  • Not Maintaining Your Wall.

What is the best footer for a retaining wall?

Regardless of the type of masonry material you are using to build the wall, concrete is the material of choice for the footer. A typical footer is twice the width of a wall and equal in depth to the wall's width. The footer should rest on a 6" gravel base set below the frost line.

What is the minimum size of footing?

Concept: For footing: i) The thickness at the edge shall not be less than 150 mm for footings on soil and not less than 300 mm for footing on piles. ii) The depth of the foundation should be a minimum of 500 mm.

How much of a retaining wall should be underground?

Dig a trench for the bottom row of blocks. They should be buried about 1 inch deep for every 8 inches of wall height. This provides strength and stability to your retaining wall. Make sure that your trench is level and compacted.

What are the basic requirements of footings?

The depth of the footing hole depends on the type of soil and the size of the building. The hole must be deep enough so that the footing is below the freeze line (the depth at which water in the ground freezes) and above any soft or loose soils. Once the hole is dug, the footing must be created.

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