§ Chapter 4 IRC 2021
Foundations
10 entries from Chapter 4 of IRC 2021, organized by section number. Each entry covers what the code requires, why it exists, what inspectors look for, and common mistakes.
§ 01 Sections
All 10 entries.
Sorted by section number. Click any row for the full entry — answer, requirements, edition diff, related sections.
Section
Title
Question
R401.4
Foundation Footings Must Bear on Undisturbed Soil or Engineered Fill
R401.4
Do house footings have to sit on undisturbed soil, or can I pour on fill?
Do house footings have to sit on undisturbed soil, or can I pour on fill?
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R403.1.1
Concrete Footing Size Depends on Loads, Stories, Soil, and Wall Type
R403.1.1
How wide and thick do concrete footings need to be for a house?
How wide and thick do concrete footings need to be for a house?
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R403.1.1
Foundation Walls Need Proper Bearing and Footing Projection
R403.1.1
How close to the edge of a footing can a foundation wall sit?
How close to the edge of a footing can a foundation wall sit?
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R403.1.3
Foundation Reinforcement Depends on Seismic Design, Wall Type, and Soil Conditions
R403.1.3
When does a foundation need rebar or special reinforcement?
When does a foundation need rebar or special reinforcement?
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R403.1.4
Exterior Footings Must Meet Minimum Depth and Frost Protection Rules
R403.1.4
How deep do footings need to be below grade and below the frost line?
How deep do footings need to be below grade and below the frost line?
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R403.1.6
Sill Plates Must Be Anchored to the Foundation with Proper Bolts or Approved Anchors
R403.1.6
How are sill plates supposed to be anchored to the foundation?
How are sill plates supposed to be anchored to the foundation?
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R403.3
Frost-Protected Shallow Foundations Need Approved Insulation Details
R403.3
Can I use a frost-protected shallow foundation instead of digging below frost depth?
Can I use a frost-protected shallow foundation instead of digging below frost depth?
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R405.1
Foundation Drains Are Required Around Many Below-Grade Enclosed Spaces
R405.1
Is a perimeter foundation drain required around my basement or crawl space?
Is a perimeter foundation drain required around my basement or crawl space?
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R406.1
Below-Grade Foundation Walls Enclosing Interior Space Must Be Dampproofed
R406.1
When does a basement foundation wall need dampproofing?
When does a basement foundation wall need dampproofing?
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R406.2
Waterproofing Is Required Where Severe Soil-Water Conditions Exist
R406.2
When is waterproofing required instead of dampproofing?
When is waterproofing required instead of dampproofing?
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