# Retaining Wall



## Durant (Sep 27, 2012)

New to this municipality,

Problem:  Permit issued to clear land; builder starts clearing.  He starts building a retaining wall to hold the fill approximately 3' so far;  and has not provided drawings for the retaining wall.  It is evidently not been the past "policy" to require drawings for retaining walls and have been allowing them without inspection as part of a "Ground Clearing Permit".

I need a code section to provide for the requirement to have drawings and inspection of retaining walls?

Thanks,


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## mtlogcabin (Sep 27, 2012)

2009 IBC

105.2 Work exempt from permit.

Exemptions from permit requirements of this code shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction. Permits shall not be required for the following:

Building:

4. Retaining walls that are not over 4 feet (1219 mm) in height measured from the bottom of the footing to the top of the wall, unless supporting a surcharge or impounding Class I, II or IIIA liquids.

Over 4 ft group "U" occupancy 312.1

1605.1.1 The stability of retaining walls shall be verified in accordance with Section 1807.2.3.

See 1610.1, 1803.5.12 if in seismic zones D through F 1807.2.2

2304.11.7 for wood retaining walls.

2009 IRC

R105.2 Work exempt from permit.

3. Retaining walls that are not over 4 feet (1219 mm) in height measured from the bottom of the footing to the top of the wall, unless supporting a surcharge.

R404.4

 Retaining walls.

Retaining walls that are not laterally supported at the top and that retain in excess of 24 inches (610 mm) of unbalanced fill shall be designed to ensure stability against overturning, sliding, excessive foundation pressure and water uplift. Retaining walls shall be designed for a safety factor of 1.5 against lateral sliding and overturning.


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## Mac (Sep 27, 2012)

Depending on how the retaining wall affects the (future) building, it may not be a building codes factor.

Doesn't help you today, but maybe the 'administration' could include the retaining wall design requirement as a change to the local ground clearing permit application?


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## Durant (Sep 27, 2012)

Ok, thanks,

The footing here must extend 18" below "undisturbed soil, so I need not concern myself with a 3' retaining wall to bring make the lot level; because it will not be effected by the building foundation?


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## tmurray (Sep 27, 2012)

Typically soil surcharge runs along at a 45˚ if you look at the foundation from a section view. If the surcharge does not act on the retaining wall then a apparently a permit is not required under the IRC and IBC. Basically if the retaining wall is further away from the structure than the foundation extends into the soil you don't really have to worry about it.


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## steveray (Sep 27, 2012)

I think MT got it......the building is irrelavent......surcharge and height are the drivers for a permit being required.....


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