• Codes
  • Features

    Features Overview

    Go to features
    Reference

    Reference.

    A reliable and up-to-date source of codes.
    Research

    Research.

    Rapidly and efficiently calculate project parameters.
    Collaboration

    Collaboration.

    Get everyone on the same page and streamline code research.
    Workflows
    Architects
    Architects
    General Contractors
    General Contractors
    Building Official & Plans Examiners
    Building Official & Plans Examiners
    Inspectors
    Inspectors
    Owners
    Owners
    Subcontractors
    Subcontractors
    Code Consultants
    Code Consultants
  • Pricing
  • Login
  • Sign Up
Sign Up
Login
  • Code Library
  • Features
  • Pricing
  • About
  • Careers
  • Help
  • Contact
  • Terms
  • Privacy
Sign Up
Upgrade to Premium
Code calculators: Code Calculators automatically generates a detailed list of requirements.
REFERENCE
Amendment Styling
Industry-leading search
Code diagrams
RESEARCH
Code calculators
Filter by topic
Code compare
Code sheet exports
COLLABORATION
Team projects
Bookmarks
Comments
START 2 WEEK FREE TRIAL
Have an account? Sign in
// CODE SNIPPET

Section R405 Foundation Drainage

Residential Code 2018 of Kansas > 4 Foundations > R405 Foundation Drainage
JUMP TO FULL CODE CHAPTER

R405.1 Concrete or Masonry Foundations

ILLUSTRATION
Drains shall be provided around concrete or masonry foundations that retain earth and enclose habitable or usable spaces located below grade. Drainage tiles, gravel or crushed stone drains, perforated pipe or other approved systems or materials shall be installed at or below the top of the footing or below the bottom of the slab and shall discharge by gravity or mechanical means into an approved drainage system. Gravel or crushed stone drains shall extend not less than 1 foot (305 mm) beyond the outside edge of the footing and 6 inches (152 mm) above the top of the footing and be covered with an approved filter membrane material. The top of open joints of drain tiles shall be protected with strips of building paper. Except where otherwise recommended by the drain manufacturer, perforated drains shall be surrounded with an approved filter membrane or the filter membrane shall cover the washed gravel or crushed rock covering the drain. Drainage tiles or perforated pipe shall be placed on not less than 2 inches (51 mm) of washed gravel or crushed rock not less than one sieve size larger than the tile joint opening or perforation and covered with not less than 6 inches (152 mm) of the same material.
Exception: A drainage system is not required where the foundation is installed on well-drained ground or sand-gravel mixture soils according to the Unified Soil Classification System, Group I soils, as detailed in Table R405.1.
TABLE R405.1
PROPERTIES OF SOILS CLASSIFIED ACCORDING TO THE UNIFIED SOIL CLASSIFICATION SYSTEM
SOIL
GROUP
UNIFIED SOIL
CLASSIFICATION
SYSTEM SYMBOL
SOIL DESCRIPTIONDRAINAGE
CHARACTERISTICSa
FROST HEAVE
POTENTIAL
VOLUME CHANGE
POTENTIAL
EXPANSIONb
Group IGWWell-graded gravels, gravel sand mixtures, little or no
fines
GoodLowLow
GPPoorly graded gravels or gravel sand mixtures, little or
no fines
GoodLowLow
SWWell-graded sands, gravelly sands, little or no finesGoodLowLow
SPPoorly graded sands or gravelly sands, little or no finesGoodLowLow
GMSilty gravels, gravel-sand-silt mixturesGoodMediumLow
SMSilty sand, sand-silt mixturesGoodMediumLow
Group IIGCClayey gravels, gravel-sand-clay mixturesMediumMediumLow
SCClayey sands, sand-clay mixtureMediumMediumLow
MLInorganic silts and very fine sands, rock flour, silty or
clayey fine sands or clayey silts with slight plasticity
MediumHighLow
CLInorganic clays of low to medium plasticity, gravelly
clays, sandy clays, silty clays, lean clays
MediumMediumMedium
to Low
Group IIICHInorganic clays of high plasticity, fat claysPoorMediumHigh
MHInorganic silts, micaceous or diatomaceous fine sandy
or silty soils, elastic silts
PoorHighHigh
Group IVOLOrganic silts and organic silty clays of low plasticityPoorMediumMedium
OHOrganic clays of medium to high plasticity, organic
silts
UnsatisfactoryMediumHigh
PtPeat and other highly organic soilsUnsatisfactoryMediumHigh
For SI: 1 inch = 25.4 mm.
  1. The percolation rate for good drainage is over 4 inches per hour, medium drainage is 2 inches to 4 inches per hour, and poor is less than 2 inches per hour.
  2. Soils with a low potential expansion typically have a plasticity index (PI) of 0 to 15, soils with a medium potential expansion have a PI of 10 to 35 and soils with a high potential expansion have a PI greater than 20.

R405.1.1 Precast Concrete Foundation

Precast concrete walls that retain earth and enclose habitable or useable space located below-grade that rest on crushed stone footings shall have a perforated drainage pipe installed below the base of the wall on either the interior or exterior side of the wall, not less than 1 foot (305 mm) beyond the edge of the wall. If the exterior drainage pipe is used, an approved filter membrane material shall cover the pipe. The drainage system shall discharge into an approved sewer system or to daylight.

R405.2 Wood Foundations

Wood foundations enclosing habitable or usable spaces located below grade shall be adequately drained in accordance with Sections R405.2.1 through R405.2.3.

R405.2.1 Base

A porous layer of gravel, crushed stone or coarse sand shall be placed to a minimum thickness of 4 inches (102 mm) under the basement floor. Provision shall be made for automatic draining of this layer and the gravel or crushed stone wall footings.

R405.2.2 Vapor Retarder

A 6-mil-thick (0.15 mm) polyethylene vapor retarder shall be applied over the porous layer with the basement floor constructed over the polyethylene.

R405.2.3 Drainage System

In other than Group I soils, a sump shall be provided to drain the porous layer and footings. The sump shall be not less than 24 inches (610 mm) in diameter or 20 inches square (0.0129 m2), shall extend not less than 24 inches (610 mm) below the bottom of the basement floor and shall be capable of positive gravity or mechanical drainage to remove any accumulated water. The drainage system shall discharge into an approved sewer system or to daylight.

Related Code Sections


Section R405 Foundations, Foundation Drainage
mm) of the same material. Exception: A drainage system is not required where the foundation is installed on well-drained ground or sand-gravel ...
Residential Code 2018 of Kansas > 4 Foundations > R405 Foundation Drainage
R405.1.1 Foundations, Precast Concrete Foundation
a perforated drainage pipe installed below the base of the wall on either the interior or exterior side of the wall, not less than 1 foot (305 mm ...
Residential Code 2018 of Kansas > 4 Foundations > R405 Foundation Drainage > R405.1 Concrete or Masonry Foundations > R405.1.1 Precast Concrete Foundation
R310.2.3.2 Building Planning, Drainage
Window wells shall be designed for proper drainage by connecting to the building's foundation drainage system required by Section R405.1 ...
Residential Code 2018 of Kansas > 3 Building Planning > R310 Emergency Escape and Rescue Openings > R310.2 Emergency Escape and Rescue Openings > R310.2.3 Window Wells > R310.2.3.2 Drainage
R310.3.2.2 Building Planning, Drainage
Area wells shall be designed for proper drainage by connecting to the building's foundation drainage system required by Section R405.1 ...
Residential Code 2018 of Kansas > 3 Building Planning > R310 Emergency Escape and Rescue Openings > R310.3 Emergency Escape and Rescue Doors > R310.3.2 Area Wells > R310.3.2.2 Drainage
R310.3.2 Building Planning, Area Wells
wells shall be designed for proper drainage by connecting to the building's foundation drainage system required by Section R405.1 or by an approved ...
Residential Code 2018 of Kansas > 3 Building Planning > R310 Emergency Escape and Rescue Openings > R310.3 Emergency Escape and Rescue Doors > R310.3.2 Area Wells
Help Contact Us Privacy Terms
Code Calculators
Code Calculators
Code calculators automatically generate a detailed list of requirements.
Code sheet exports
Code sheet exports
Generate a code sheet that integrates with your drawing set.
Code diagrams
Code diagrams
Unpack the code through illustrations and descriptions.
Shared projects
Shared projects
Projects provide a dedicated space to collaborate on code research.
Code Compare
Code Compare
Highlight differences between any two building codes.
Search
Search
Don't miss relevant code. Quickly locate sections across your jurisdiction.
UpCodes Premium
Leverage the most sophisticated code compliance platform.
VISIT PRICING
UpCodes Premium
Leverage the full code compliance platform.
START 2 WEEK FREE TRIAL PRICING