Minnesota Administrative Rules
Agency 151 - Labor and Industry Department
Chapter 1309 - INTERNATIONAL RESIDENTIAL CODE
Part 1309.0404 - SECTION R404, FOUNDATION AND RETAINING WALLS
Universal Citation: MN Rules 1309.0404
Current through Register Vol. 49, No. 13, September 23, 2024
Subpart 1. IRC section R404.1.
Section R404.1 is amended to read as follows:
R404.1
Concrete and masonry foundation
walls. Concrete foundation walls shall be selected and constructed in
accordance with the provisions of section R404.1.2. Masonry foundation walls
shall be selected and constructed in accordance with the provisions of section
R404.1.1. Concrete and masonry foundation walls shall be laterally supported at
the top and bottom. Foundation walls that meet all of the following shall be
considered laterally supported:
1. Full
basement floor shall be 3.5 inches (89 mm) thick concrete slab poured tight
against the bottom of the foundation wall.
2. Floor joists and blocking shall be
connected to the sill plate at the top of wall with an approved connector with
listed capacity meeting the top of wall reaction in Table R404.1(1). Maximum
spacing of floor joists shall be 24 inches on center. Spacing of blocking shall
be in accordance with Table R404.1(1).
3. Bolt spacing for the sill plate shall be
no greater than the requirements in Table R404.1(1).
4. The floor shall be blocked perpendicular
to the floor joists. Blocking shall be full depth within three joist spaces of
the foundation wall. Floor sheathing shall be fastened to blocking in
accordance with Table R602.3(1).
5.
Where foundation walls support unbalanced load on opposite sides of the
building, such as a daylight basement, the rim board shall be attached to the
sill with a 20-gage metal angle clip at 24 inches on center, with five 8d nails
per leg, or an approved connector supplying 230 pounds per lineal foot
capacity.
Exception: Cantilevered concrete and masonry foundation walls that do not have permanent lateral support at the top shall be constructed according to Table R404.1.1(5), Table R404.1.1(6), or Table R404.1.1(7).
Subp. 2. IRC Table R404.1(1).
Section R404.1 is amended by adding Table R404.1(1) as follows:
TABLE R404.1(1) MAXIMUM ANCHOR BOLT AND BLOCKING SPACING FOR SUPPORTED FOUNDATION WALL
| Max. Wall Height | Max. Unbalanced Backfill Height | Soil Classes | Soil Load (pcf/ft) | Top of Wall Reaction (plf)b | 1/2" diameter Anchor Bolt Spacing (inches)a | Spacing of Blocking Perpendicular To Floor Joists (inches) |
| GW, GP, SW, & SP | 30 | 250 | 72 | 60 | ||
| 8'-0" | 7'-4" | GM, GC, SM-SC, & ML | 45 | 370 | 72 | 40 |
| SC, MH, ML-CL, & I-CL | 60 | 490 | 48 | 30 | ||
| GW, GP, SW, & SP GM, GC, SM-SC, | 30 | 320 | 72 | 48 | ||
| 9'-0" | 8'-4" | &ML SC, MH, ML-CL, | 45 | 480 | 48 | 32 |
| &I-CL | 60 | 640 | 40 | 24 |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm
a Sill plate shall be 2 x 6 minimum. Anchor bolt shall be minimum 0.5" diameter cast-in-place with 7" embed. Anchor bolt shall have a 2" diameter by 0.125" thick washer tightened and countersunk 0.25" into the top of the sill plate.
b Minimum load to be used for sizing of accepted anchors or fasteners if bolts are not used.
Subp. 3. [Repealed, ]
Subp. 4. [Repealed, ]
Subp. 5. [Repealed, ]
Subp. 6. IRC Table R404.1.1(5).
Section R404 is amended by adding a new table as follows:
TABLE R404.1.1(5) CANTILEVERED CONCRETE AND MASONRY FOUNDATION WALLS
| Maximum Wall Heightj (feet) | Maximum Unbalanced Backfill Heighte (feet) | Minimum Vertical Reinforcement Size and Spacing for 8-Inch Nominal Wall Thickness a,b,c,e,f,i,k | ||
| Soil Classesd | ||||
| GW, GP, SW, and SP | GM, GC, SM, SM-SC, and ML | SC, MH, ML-CL, and inorganic CL | ||
| 4 | 3 | None required | None required | None required |
| 4 | None required | None required | No. 4 @ 72 in. o.c. | |
| 5 | 3 | None required | None required | None required |
| 4 | No. 4 @ 72 in. o.c. | No. 4 @ 56 in. o.c.h | No. 4 @ 40 in. o.c.g | |
| 5 | No. 4 @ 72 in. o.c. | No. 4 @ 56 in. o.c.h | No. 4 @ 40 in. o.c.g | |
a. Mortar shall
be Type M or S and masonry shall be laid in running bond. Minimum unit
compressive strength is 1,900 psi.
b. Alternative reinforcing bar sizes and
spacings having an equivalent cross-sectional area of reinforcement per lineal
foot of wall shall be permitted provided the spacing of the reinforcement does
not exceed 72 inches.
c. Vertical
reinforcement shall be Grade 60 minimum. The distance from the face of the soil
side of the wall to the center of vertical reinforcement shall be no greater
than 2.5 inches.
d. Soil classes
are in accordance with the Unified Soil Classification System. Refer to Table
R405.1.
e. Interior concrete floor
slab-on-grade shall be placed tight to the wall. The exterior grade level shall
be 6 inches minimum below the top of wall. Maximum height from top of
slab-on-grade to bottom of floor joists is 10 feet, 0 inches. Unbalanced
backfill height is the difference in height of the exterior finish ground
levels and the top of the interior concrete slab-on-grade.
f. Minimum footing size of 20 inches by 8
inches shall be placed on soil with a bearing capacity of 2,000 psf. Minimum
concrete compressive strength of footing shall be 3,000 psi.
g. Provide propped cantilever wall: top of
footing shall be 16 inches below the bottom of the concrete floor slab
minimum.
h. Provide #5 Grade 60
dowels, 1 foot, 6 inches long, to connect footing to wall. Embed dowel 5 inches
into footing. Place dowels in center of wall thickness spaced at 32 inches on
center maximum. No dowels are required where length of the foundation wall
between perpendicular walls is two times the foundation wall height or
less.
i. This table is applicable
where the length of the foundation wall between perpendicular walls is 35 feet
or less, or where the length of the foundation laterally supported on only one
end by a perpendicular wall is 17 feet or less.
j. Maximum wall height is measured from top
of the foundation wall to the bottom of the interior concrete
slab-on-grade.
k. Install
foundation anchorage per section R403.1.6.
Subp. 7. IRC Table R404.1.1(6).
IRC Section R404 is amended by adding a new table as follows:
TABLE R404.1.1(6) CANTILEVERED CONCRETE AND MASONRY FOUNDATION WALLS
| Maximum Wall Heightj (feet) | Maximum Unbalanced Backfill Heighte (feet) | Minimum Vertical Reinforcement Size and Spacing for 10-Inch Nominal Wall Thickness a,b,c,e,f,i,k | ||
| Soil Classesd | ||||
| GW, GP, SW, and SP | GM, GC, SM, SM-SC, and ML | SC, MH, ML-CL, and inorganic CL | ||
| 4 | 3 | None required | None required | None required |
| 4 | None required | None required | None required | |
| 5 | 3 | None required | None required | None required |
| 4 | None required | No. 4 @ 72 in. o.c. | No. 4 @ 64 in. o.c.g | |
| 5 | No. 4 @ 72 in. o.c. | No. 4 @ 72 in. o.c. | No, 4 @ 56 in. o.c.g | |
| 6 | 3 | None required | No. 4 @ 72 in. o.c. | No. 4 @ 72 in. o.c. |
| 4 | No. 4 @ 72 in. o.c. | No. 4 @ 72 in. o.c. | No. 4 @ 64 in. o.c.h | |
| 5 | No. 4 @ 64 in. o.c.h | No. 4 @ 40 in. o.c.g,h | No. 5 @ 48 in. o.c.g,h | |
| 6 | No. 4 @ 64 in. o.c.h | No. 4 @ 40 in. o.c.g,h | No. 5 @ 48 in. o.c.g,h | |
a. Mortar shall
be Type M or S and masonry shall be laid in running bond. Minimum unit
compressive strength is 1,900 psi.
b. Alternative reinforcing bar sizes and
spacings having an equivalent cross-sectional area of reinforcement per lineal
foot of wall shall be permitted provided the spacing of the reinforcement does
not exceed 72 inches.
c. Vertical
reinforcement shall be Grade 60 minimum. The distance from the face of the soil
side of the wall to the center of vertical reinforcement shall be no greater
than 2.5 inches.
d. Soil classes
are in accordance with the Unified Soil Classification System. Refer to Table
R405.1.
e. Interior concrete
slab-on-grade shall be placed tight to the wall. The exterior grade level shall
be 6 inches minimum below the top of wall. Maximum height from top of
slab-on-grade to bottom of floor joists is 10 feet, 0 inches. Unbalanced
backfill height is the difference in height of the exterior finish ground
levels and the top of the interior concrete slab-on-grade.
f. Minimum footing size of 20 inches by 8
inches shall be placed on soil with a bearing capacity of 2,000 psf. Minimum
concrete compressive strength of footing shall be 3,000 psi.
g. Provide propped cantilever wall: top of
footing shall be 16 inches below the bottom of the concrete floor slab
minimum.
h. Provide #5 Grade 60
dowels, 1 foot, 6 inches long, to connect footing to wall. Embed dowel 5 inches
into footing. Place dowels in center of wall thickness spaced at 32 inches on
center maximum. No dowels are required where length of the foundation wall
between perpendicular walls is two times the foundation wall height or
less.
i. This table is applicable
where the length of the foundation wall between perpendicular walls is 35 feet
or less, or where the length of the foundation laterally supported on only one
end by a perpendicular wall is 17 feet or less.
j. Maximum wall height is measured from top
of the foundation wall to the bottom of the interior concrete
slab-on-grade.
k. Install
foundation anchorage per section R403.1.6.
Subp. 8. IRC Table R404.1.1(7).
Section R404 is amended by adding a new table as follows:
TABLE R404.1.1(7) CANTILEVERED CONCRETE AND MASONRY FOUNDATION WALLS
| Maximum Wall Heightj (feet) | Maximum Unbalance Backfill Heighte (feet) | Minimum Vertical Reinforcement Size and Spacing for 12-Inch Nominal Wall Thicknessa,b,c,e,f,i,k | ||
| Soil Classesd | ||||
| GW, GP, SW, and SP | GM, GC, SM, SM-SC, and ML | SC, MH, ML-CL, and inorganic CL | ||
| 4 | 3 | None required | None required | None required |
| 4 | None required | None required | None required | |
| 5 | 3 | None required | None required | None required |
| 4 | None required | None required | No. 4 @ 72 in. o.c. | |
| 5 | No. 4 @ 72 in. o.c. | No. 4 @ 72 in. o.c. | No. 4 @ 72 in. o.c. | |
| 6 | 3 | None required | None required | None required |
| 4 | None required | None required | No. 4 @ 72 in. o.c. | |
| 5 | No. 4 @ 72 in. o.c. | No. 4 @ 56 in. o.c.h | No. 4 @ 40 in. o.c.g | |
| 6 | No. 4 @ 72 in. o.c. | No. 4 @ 56 in. o.c.g | No. 4 @ 32 in. g.h | |
| 7 | 3 | None required | None required | None required |
| 4 | None required | No. 4 @ 72 in. o.c. | No. 4 @ 72 in. o.c. | |
| 5 | No. 4 @ 72 in. o.c. | No. 4 @ 56 in. o.c.h | No. 4 @ 40 in. o.c.g | |
| 6 | No. 4 @ 48 in. o.c.h | No. 5 @ 48 in. o.c.g.h | No. 6 @ 48 in. o.c.g.h | |
| 7 | No. 4 @ 48 in. o.c.h | No. 5 @ 40 in. o.c.g,h | No. 6 @ 48 in. o.c.g,h | |
a. Mortar shall
be Type M or S and masonry shall be laid in running bond. Minimum unit
compressive strength is 1,900 psi.
b. Alternative reinforcing bar sizes and
spacings having an equivalent cross-sectional area of reinforcement per lineal
foot of wall shall be permitted provided the spacing of the reinforcement does
not exceed 72 inches.
c. Vertical
reinforcement shall be Grade 60 minimum. The distance from the face of the soil
side of the wall to the center of vertical reinforcement shall be no greater
than 3 inches.
d. Soil classes are
in accordance with the Unified Soil Classification System. Refer to Table
R405.1.
e. Interior concrete
slab-on-grade shall be placed tight to the wall. The exterior grade level shall
be 6 inches minimum below the top of wall. Maximum height from top of
slab-on-grade to bottom of floor joists is 10 feet, 0 inches. Unbalanced
backfill height is the difference in height of the exterior finish ground
levels and the top of the interior concrete slab-on-grade.
f. Minimum footing size of 20 inches by 8
inches shall be placed on soil with a bearing capacity of 2,000 psf. Minimum
concrete compressive strength of footing shall be 3,000 psi.
g. Provide propped cantilever wall: top of
footing shall be 16 inches below the bottom of the concrete floor slab
minimum.
h. Provide #5 Grade 60
dowels, 1 foot, 6 inches long, to connect footing to wall. Embed dowel 5 inches
into footing. Place dowels in center of wall thickness spaced at 32 inches on
center maximum. No dowels are required where length of the foundation wall
between perpendicular walls is two times the foundation wall height or
less.
i. This table is applicable
where the length of the foundation wall between perpendicular walls is 35 feet
or less, or where the length of the foundation laterally supported on only one
end by a perpendicular wall is 17 feet or less.
j. Maximum wall height is measured from top
of the foundation wall to the bottom of the interior concrete
slab-on-grade.
k. Install
foundation anchorage per section R403.1.6.
Subp. 9. IRC section R404.1.3.
Section R404.1.3 is amended by adding the following exception to condition 2:
Exception: Cantilevered concrete and masonry foundation walls constructed in accordance with Table R404.1.1(5), R404.1.1(6) or R404.1.1(7).
Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326B.101; 326B.106; 326B.13
Disclaimer: These regulations may not be the most recent version. Minnesota may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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