International Building Code Section 1807


International Building Code 1807.1

Where required. Walls or portions thereof that retain
earth and enclose interior spaces and floors below grade shall
bewaterproofed and dampproofed in accordance with this section,
with the exception of those spaces containing groups
other than residential and institutional where such omission is
not detrimental to the building or occupancy.
Ventilation for crawl spaces shall comply with Section
1203.4.

Story above grade plane. Where a basement is
considered a story above grade plane and the finished
ground level adjacent to the basement wall is below the
basement floor elevation for 25 percent or more of the perimeter,
the floor and walls shall be dampproofed in accordance
with Section 1807.2 and a foundation drain shall be
installed in accordance with Section 1807.4.2. The foundation
drain shall be installed around the portion of the perimeter
where the basement floor is below ground level. The
provisions of Sections 1802.2.3, 1807.3 and 1807.4.1 shall
not apply in this case.

Under-floor space. The finished ground level of
an under-floor space such as a crawl space shall not be
located belowthe bottom of the footings. Where there is evidence
that the ground-water table rises to within 6 inches
(152 mm) of the ground level at the outside building perimeter,
or that the surface water does not readily drain from the
building site, the ground level of the under-floor space shall
be as high as the outside finished ground level, unless an
approved drainage system is provided. The provisions of
Sections 1802.2.3, 1807.2, 1807.3 and 1807.4 shall not
apply in this case.

Flood hazard areas. For buildings and structures
in flood hazard areas as established in Section
1612.3, the finished ground level of an under-floor space
such as a crawl space shall be equal to or higher than the
outside finished ground level.
Exception: Under-floor spaces of Group R-3 buildings
that meet the requirements of FEMA/
FIA-TB-11.

Ground-water control. Where the ground-water
table is lowered and maintained at an elevation not less than
6 inches (152 mm) below the bottom of the lowest floor, the
floor and walls shall be dampproofed in accordance with
Section 1807.2. The design of the system to lower the
ground-water table shall be based on accepted principles of
engineering that shall consider, but not necessarily be limited
to, permeability of the soil, rate at which water enters
the drainage system, rated capacity of pumps, head against
which pumps are to operate and the rated capacity of the disposal
area of the system.

International Building Code 1807.1.1

Story above grade plane. Where a basement is
considered a story above grade plane and the finished
ground level adjacent to the basement wall is below the
basement floor elevation for 25 percent or more of the perimeter,
the floor and walls shall be dampproofed in accordance
with Section 1807.2 and a foundation drain shall be
installed in accordance with Section 1807.4.2. The foundation
drain shall be installed around the portion of the perimeter
where the basement floor is below ground level. The
provisions of Sections 1802.2.3, 1807.3 and 1807.4.1 shall
not apply in this case.

International Building Code 1807.1.2

Under-floor space. The finished ground level of
an under-floor space such as a crawl space shall not be
located belowthe bottom of the footings. Where there is evidence
that the ground-water table rises to within 6 inches
(152 mm) of the ground level at the outside building perimeter,
or that the surface water does not readily drain from the
building site, the ground level of the under-floor space shall
be as high as the outside finished ground level, unless an
approved drainage system is provided. The provisions of
Sections 1802.2.3, 1807.2, 1807.3 and 1807.4 shall not
apply in this case.

Flood hazard areas. For buildings and structures
in flood hazard areas as established in Section
1612.3, the finished ground level of an under-floor space
such as a crawl space shall be equal to or higher than the
outside finished ground level.
Exception: Under-floor spaces of Group R-3 buildings
that meet the requirements of FEMA/
FIA-TB-11.

International Building Code 1807.1.2.1

Flood hazard areas. For buildings and structures
in flood hazard areas as established in Section
1612.3, the finished ground level of an under-floor space
such as a crawl space shall be equal to or higher than the
outside finished ground level.
Exception: Under-floor spaces of Group R-3 buildings
that meet the requirements of FEMA/
FIA-TB-11.

International Building Code 1807.1.3

Ground-water control. Where the ground-water
table is lowered and maintained at an elevation not less than
6 inches (152 mm) below the bottom of the lowest floor, the
floor and walls shall be dampproofed in accordance with
Section 1807.2. The design of the system to lower the
ground-water table shall be based on accepted principles of
engineering that shall consider, but not necessarily be limited
to, permeability of the soil, rate at which water enters
the drainage system, rated capacity of pumps, head against
which pumps are to operate and the rated capacity of the disposal
area of the system.

International Building Code 1807.2

Dampproofing required. Where hydrostatic pressure
will not occur as determined by Section 1802.2.3, floors and
walls for other than wood foundation systems shall be
dampproofed in accordance with this section. Wood foundation
systems shall be constructed in accordance with AF&PA
Technical Report No. 7.

Floors. Dampproofing materials for floors shall
be installed between the floor and the base course required
by Section 1807.4.1, except where a separate floor is provided
above a concrete slab.
Where installed beneath the slab, dampproofing shall
consist of not less than 6-mil (0.006 inch; 0.152 mm) polyethylene
with joints lapped not less than 6 inches (152 mm),
or other approved methods or materials. Where permitted to
be installed on top of the slab, dampproofing shall consist of
mopped-on bitumen, not less than 4-mil (0.004 inch; 0.102
mm) polyethylene, or other approved methods or materials.
Joints in the membrane shall be lapped and sealed in accordance
with the manufacturer’s installation instructions.

Walls. Dampproofing materials for walls shall be
installed on the exterior surface of thewall, and shall extend
from the top of the footing to above ground level.
Dampproofing shall consist of a bituminous material, 3
pounds per square yard (16 N/m2) of acrylic modified
cement, 0.125 inch (3.2 mm) coat of surface-bonding mortar
complying with ASTM C 887, any of the materials permitted
for waterproofing by Section 1807.3.2 or other
approved methods or materials.

Surface preparation of walls. Prior to application
of dampproofing materials on concrete walls,
holes and recesses resulting from the removal of form
ties shall be sealed with a bituminous material or other
approved methods or materials. Unit masonrywalls shall
be parged on the exterior surface belowground level with
not less than 0.375 inch (9.5 mm) of portland cement
mortar. The parging shall be coved at the footing.
Exception: Parging of unit masonry walls is not
required where a material is approved for direct application
to the masonry.
2006 INTERNATIONAL BUILDING CODE 357
SOILS AND FOUNDATIONS

International Building Code 1807.2.1

Floors. Dampproofing materials for floors shall
be installed between the floor and the base course required
by Section 1807.4.1, except where a separate floor is provided
above a concrete slab.
Where installed beneath the slab, dampproofing shall
consist of not less than 6-mil (0.006 inch; 0.152 mm) polyethylene
with joints lapped not less than 6 inches (152 mm),
or other approved methods or materials. Where permitted to
be installed on top of the slab, dampproofing shall consist of
mopped-on bitumen, not less than 4-mil (0.004 inch; 0.102
mm) polyethylene, or other approved methods or materials.
Joints in the membrane shall be lapped and sealed in accordance
with the manufacturer’s installation instructions.

International Building Code 1807.2.2

Walls. Dampproofing materials for walls shall be
installed on the exterior surface of thewall, and shall extend
from the top of the footing to above ground level.
Dampproofing shall consist of a bituminous material, 3
pounds per square yard (16 N/m2) of acrylic modified
cement, 0.125 inch (3.2 mm) coat of surface-bonding mortar
complying with ASTM C 887, any of the materials permitted
for waterproofing by Section 1807.3.2 or other
approved methods or materials.

Surface preparation of walls. Prior to application
of dampproofing materials on concrete walls,
holes and recesses resulting from the removal of form
ties shall be sealed with a bituminous material or other
approved methods or materials. Unit masonrywalls shall
be parged on the exterior surface belowground level with
not less than 0.375 inch (9.5 mm) of portland cement
mortar. The parging shall be coved at the footing.
Exception: Parging of unit masonry walls is not
required where a material is approved for direct application
to the masonry.
2006 INTERNATIONAL BUILDING CODE 357
SOILS AND FOUNDATIONS

International Building Code 1807.2.2.1

Surface preparation of walls. Prior to application
of dampproofing materials on concrete walls,
holes and recesses resulting from the removal of form
ties shall be sealed with a bituminous material or other
approved methods or materials. Unit masonrywalls shall
be parged on the exterior surface belowground level with
not less than 0.375 inch (9.5 mm) of portland cement
mortar. The parging shall be coved at the footing.
Exception: Parging of unit masonry walls is not
required where a material is approved for direct application
to the masonry.
2006 INTERNATIONAL BUILDING CODE 357
SOILS AND FOUNDATIONS

International Building Code 1807.3

Waterproofing required. Where the ground-water
investigation required by Section 1802.2.3 indicates that a
hydrostatic pressure condition exists, and the design does not
include a ground-water control system as described in Section
1807.1.3, walls and floors shall be waterproofed in accordance
with this section.

Floors. Floors required to be waterproofed shall
be of concrete and designed and constructed to withstand
the hydrostatic pressures to which the floors will be subjected.
Waterproofing shall be accomplished by placing a
membrane of rubberized asphalt, butyl rubber, fully
adhered/fully bonded HDPE or polyolefin composite membrane
or not less than 6-mil [0.006 inch (0.152 mm)] polyvinyl
chloride with joints lapped not less than 6 inches (152
mm) or other approved materials under the slab. Joints in the
membrane shall be lapped and sealed in accordance with the
manufacturer’s installation instructions.

Walls.Walls required to be waterproofed shall be
of concrete or masonry and shall be designed and constructed
to withstand the hydrostatic pressures and other lateral
loads to which the walls will be subjected.
Waterproofing shall be applied from the bottom of the
wall to not less than 12 inches (305 mm) above the maximum
elevation of the ground-water table. The remainder of
the wall shall be dampproofed in accordance with Section
1807.2.2. Waterproofing shall consist of two-ply
hot-mopped felts, not less than 6-mil (0.006 inch; 0.152
mm) polyvinyl chloride, 40-mil (0.040 inch; 1.02 mm)
polymer-modified asphalt, 6-mil (0.006 inch; 0.152 mm)
polyethylene or other approved methods or materials capable
of bridging nonstructural cracks. Joints in the membrane
shall be lapped and sealed in accordance with the manufacturer’s
installation instructions.

Surface preparation of walls. Prior to the
application of waterproofing materials on concrete or
masonry walls, the walls shall be prepared in accordance
with Section 1807.2.2.1.

Joints and penetrations. Joints in walls and
floors, joints between the wall and floor and penetrations of
the wall and floor shall be made water-tight utilizing
approved methods and materials.

International Building Code 1807.3.1

Floors. Floors required to be waterproofed shall
be of concrete and designed and constructed to withstand
the hydrostatic pressures to which the floors will be subjected.
Waterproofing shall be accomplished by placing a
membrane of rubberized asphalt, butyl rubber, fully
adhered/fully bonded HDPE or polyolefin composite membrane
or not less than 6-mil [0.006 inch (0.152 mm)] polyvinyl
chloride with joints lapped not less than 6 inches (152
mm) or other approved materials under the slab. Joints in the
membrane shall be lapped and sealed in accordance with the
manufacturer’s installation instructions.

International Building Code 1807.3.2

Walls.Walls required to be waterproofed shall be
of concrete or masonry and shall be designed and constructed
to withstand the hydrostatic pressures and other lateral
loads to which the walls will be subjected.
Waterproofing shall be applied from the bottom of the
wall to not less than 12 inches (305 mm) above the maximum
elevation of the ground-water table. The remainder of
the wall shall be dampproofed in accordance with Section
1807.2.2. Waterproofing shall consist of two-ply
hot-mopped felts, not less than 6-mil (0.006 inch; 0.152
mm) polyvinyl chloride, 40-mil (0.040 inch; 1.02 mm)
polymer-modified asphalt, 6-mil (0.006 inch; 0.152 mm)
polyethylene or other approved methods or materials capable
of bridging nonstructural cracks. Joints in the membrane
shall be lapped and sealed in accordance with the manufacturer’s
installation instructions.

Surface preparation of walls. Prior to the
application of waterproofing materials on concrete or
masonry walls, the walls shall be prepared in accordance
with Section 1807.2.2.1.

International Building Code 1807.3.2.1

Surface preparation of walls. Prior to the
application of waterproofing materials on concrete or
masonry walls, the walls shall be prepared in accordance
with Section 1807.2.2.1.

International Building Code 1807.3.3

Joints and penetrations. Joints in walls and
floors, joints between the wall and floor and penetrations of
the wall and floor shall be made water-tight utilizing
approved methods and materials.

International Building Code 1807.4

Subsoil drainage system. Where a hydrostatic pressure
condition does not exist, dampproofing shall be provided
and a base shall be installed under the floor and a drain installed
around the foundation perimeter. A subsoil drainage system
designed and constructed in accordance with Section 1807.1.3
shall be deemed adequate for lowering the ground-water table.

Floor base course. Floors of basements, except as
provided for in Section 1807.1.1, shall be placed over a floor
base course not less than 4 inches (102 mm) in thickness that
consists of gravel or crushed stone containing not more than
10 percent of material that passes through a No. 4 (4.75 mm)
sieve.
Exception: Where a site is located in well-drained gravel
or sand/gravel mixture soils, a floor base course is not
required.

Foundation drain.Adrain shall be placed around
the perimeter of a foundation that consists of gravel or
crushed stone containing not more than 10-percent material
that passes through a No. 4 (4.75 mm) sieve. The drain shall
extend a minimum of 12 inches (305 mm) beyond the outside
edge of the footing. The thickness shall be such that the
bottom of the drain is not higher than the bottom of the base
under the floor, and that the top of the drain is not less than 6
inches (152 mm) above the top of the footing. The top of the
drain shall be covered with an approved filter membrane
material. Where a drain tile or perforated pipe is used, the
invert of the pipe or tile shall not be higher than the floor elevation.
The top of joints or the top of perforations shall be
protected with an approved filter membrane material. The
pipe or tile shall be placed on not less than 2 inches (51 mm)
of gravel or crushed stone complying with Section
1807.4.1, and shall be covered with not less than 6 inches
(152 mm) of the same material.

Drainage discharge. The floor base and foundation
perimeter drain shall discharge by gravity or mechanical
means into an approved drainage system that complies
with the International Plumbing Code.
Exception: Where a site is located in well-drained gravel
or sand/gravel mixture soils, a dedicated drainage system
is not required.

International Building Code 1807.4.1

Floor base course. Floors of basements, except as
provided for in Section 1807.1.1, shall be placed over a floor
base course not less than 4 inches (102 mm) in thickness that
consists of gravel or crushed stone containing not more than
10 percent of material that passes through a No. 4 (4.75 mm)
sieve.
Exception: Where a site is located in well-drained gravel
or sand/gravel mixture soils, a floor base course is not
required.

International Building Code 1807.4.2

Foundation drain.Adrain shall be placed around
the perimeter of a foundation that consists of gravel or
crushed stone containing not more than 10-percent material
that passes through a No. 4 (4.75 mm) sieve. The drain shall
extend a minimum of 12 inches (305 mm) beyond the outside
edge of the footing. The thickness shall be such that the
bottom of the drain is not higher than the bottom of the base
under the floor, and that the top of the drain is not less than 6
inches (152 mm) above the top of the footing. The top of the
drain shall be covered with an approved filter membrane
material. Where a drain tile or perforated pipe is used, the
invert of the pipe or tile shall not be higher than the floor elevation.
The top of joints or the top of perforations shall be
protected with an approved filter membrane material. The
pipe or tile shall be placed on not less than 2 inches (51 mm)
of gravel or crushed stone complying with Section
1807.4.1, and shall be covered with not less than 6 inches
(152 mm) of the same material.

International Building Code 1807.4.3

Drainage discharge. The floor base and foundation
perimeter drain shall discharge by gravity or mechanical
means into an approved drainage system that complies
with the International Plumbing Code.
Exception: Where a site is located in well-drained gravel
or sand/gravel mixture soils, a dedicated drainage system
is not required.