Foundation process according to Florida building code

Generalities

Applications

All provisions of this topic shall control the design and construction of foundations and foundation spaces for buildings. In addition to the provisions of this topic, the design and construction of foundations in flood hazard areas must comply with other provisions recognized by the Florida residential building code. Wood foundations shall be designed and installed in accordance with this code.

Exceptions

Chapter 4 of the Florida residential building code offers a series of provisions which allow wood foundations only under these conditions:

• Constructions that do not have more than two floors and a roof.
• Where the interior basement and foundation walls are constructed at intervals not to exceed 50 feet.
• Constructions and structures located within the high-velocity hurricane zone.

Timber designs in seismic design categories D0, D1, or D2 are designed in accordance with accepted engineering practice.

Requirements

The foundation must be constructed to resist all loads from roof loads and building turns. The foundation estimate for wood or light-frame steel construction shall be calculated or determined in accordance with Table R401.1.

Masonry constructions within the dimensional scope of Table R401.1 are assumed to be of adequate weight so as not to require a frequency strength greater than that specified by the I-frame and any normal foundation.

The foundation construction must also be capable of accommodating all gravity loads and transmitting the resulting loads to the supporting soil. Fill soils supporting footings and foundations shall be designed, installed and tested in accordance with accepted engineering practice. Gravel fill used as footings for wood and precast concrete foundations must comply with footings Section.

Sewer system

Surface drainage shall be diverted to a storm sewer or other approved collection point that does not create a hazard. Lots will be graded to drain surface water away from foundation walls. The slope must drop a minimum of 6 inches within the first 10 feet.

Exceptions

Where lot lines, walls, slopes or other physical barriers prohibit a drop of 6 inches within 10 feet, drains or channels must be constructed to ensure drainage away from the structure. Impervious surfaces within 10 feet of the building foundation must have a minimum slope of 2% of the building.

Soil tests

If there are indications that the soil has expansive, compressible, shifting or other questionable characteristics, the building official will need to determine whether to perform a soil test to determine the characteristics of the soil at any location.

Geotechnical evaluation

In lieu of a full geotechnical evaluation, the load values in Table R401.4.1 shall be adopted.

• Where soil testing is required, the allowable bearing capacities of the soil shall be part of the recommendations.
• If it is determined that on-site soils with an allowable bearing capacity of less than 1,500 psf are likely present at the site, the allowable bearing capacity will be determined by a soil investigation.

Compressible or shifting soil

In lieu of a full geotechnical evaluation, where the top or subsoils are compressible or displaceable, they should be removed to a depth and width sufficient to ensure a stable moisture content in each active zone and should not be used as fill or stabilized within each active zone due to chemicals, dehydration or pre-saturation.

Materials

Wooden foundation

All wood foundations must be designed and installed in accordance with the recommendations of Chapter 4 of the Florida Residential Building Code.

Fasteners

Fasteners used in knee wall construction shall be Type 304 or 316 stainless steel. Fasteners used above grade for joining plywood and all wood and hopper fasteners, except those used in knee wall construction, shall be Type 304 or 316 stainless steel, silicon bronze, copper, nails hot dipped galvanized steel (zinc coated), or hot rolled galvanized steel nails.

Wood treatment

Wood should be pressure treated with preservatives and dried after treatment in accordance with AWPAUI. When lumber and/or plywood is cut or drilled after treatment, the treated surface must be treated in the field with copper naphthenate, the concentration of which must contain a minimum of 2% metallic copper, by brushing, dipping or soaking.

Concrete

Concrete shall have a minimum specified compressive strength of f'c, as shown in Table R402.2. Concrete subjected to moderate or severe weathering as specified in Table R301.2(1) shall be air-entrained as specified in Table R402.2.

Materials for concrete

All concrete materials must meet the requirements of the concrete and concrete materials Section of the Florida residential building code.

Prefabricated concrete

Precast concrete foundations must be designed in accordance with Section Precast Concrete Foundations below and installed in accordance with the provisions of this code and the manufacturer's instructions.

Materials for precast concrete foundation

The materials used to produce precast concrete foundations shall meet the following requirements.

• All concrete used in the manufacture of precast concrete foundations shall have a minimum compressive strength of 5,000 psi at 28 days. Concrete exposed to a freeze-thaw environment must be air-entrained with a minimum total air content of 5%.
• Structural reinforcing steel must meet the requirements of ASTM A615, A 706, or A996. The minimum yield strength of the reinforcing steel shall be 40,000 psi (Grade 40). Steel reinforcement for precast concrete foundation walls must have a minimum 3/4-inch concrete cover.
• Panel to panel connections will be made with grade II steel fasteners.
• The use of non-structural fibers must comply with ASTM C1 116.
• Grout used for precast bed foundations placed on concrete foundations must comply with ASTM C1 107.

Masonry

Masonry systems shall be designed and installed in accordance with this chapter and shall have a minimum specified compressive strength of 1,500 psi.

Footings

Generalities

All exterior walls shall be supported on continuous solid or fully grouped masonry footings or concrete footings, crushed stone footings, wood foundations or other approved structural systems which shall be of sufficient design to accommodate all loads and transmit the resulting loads to The ground.

Within the limitations determined by the character of the soil. Footings must be supported on undisturbed or filled natural soils.

Minimum size

The minimum width, W, and thickness, T, for concrete footings shall be in accordance with Tables R403.1(1) through R403.1(3) as applicable. Minimum sizes for concrete and masonry footings shall also be required to provide adequate resistance to uplift and overturning of the construction.

The width of the base shall be based on the soil load value in accordance with Table R401.4.1. Footing projections, P, shall not be less than 2 inches and shall not exceed the thickness of the footing. The size of footings supporting pillars and columns shall be based on the tributary load and allowable soil pressure in accordance with Table R401.4.1.

Lifting resistance

The uplift resistance of these foundations can be increased by increasing the size of the concrete base. When determining the modified lifting resistance, the added weight will be reduced by multiplying by a factor of 0.6.

Minimum depth

Exterior footings shall be placed not less than 12 inches below the ground surface without disturbance.

Frost protection

Except where protected from frost, foundation walls, piers and other permanent supports of buildings and structures shall be protected from frost by one or more of the following methods:

• Extended below the frost line specified in Table R301.2.(1) located at the end of the chapter
• Built in accordance with ASCE32 standard.
• Erected on solid rock.

Exceptions

• Protection will not be required for free-standing accessory structures with an area of 600 square feet or less, of light frame construction, with an eave height of 10 feet or less.
• Protection of free-standing accessory structures with an area of 400 square feet or less, other than of light frame construction, with an eave height of 10 feet or less, shall not be required.
• Decks not supported by a dwelling do not need to have footings that extend below the frost line.

Footings should not support frozen ground unless the frozen condition is permanent.

Slope

The top surface of the shoes must be leveled. The bottom surface of the footings must not have a slope greater than one vertical unit in 10 horizontal units (10% slope).

Foundation anchoring

Wood sill plates and wood walls supported directly on continuous foundations shall be anchored to the foundation in accordance with this section.

The cold-formed steel frame should be anchored directly to the foundation or fastened to wood sill plates anchored to the foundation. The anchorage of the cold-formed steel frame and the sill plates supporting the cold-formed steel frame shall be in accordance with this section.

Wood sole plates on all exterior walls in monolithic slabs, wood sole plates of reinforced wall panels on the interiors of monolithic slab construction, and all wood sill plates must be anchored to the foundation. with (1/2-inch) minimum diameter anchor bolts spaced a maximum of 6 feet on center or approved anchors or anchor straps spaced as necessary to provide anchorage equivalent to (1/2-inch) anchor bolts in diameter.

Bolts must extend a minimum of 7 inches into the concrete or clustered cells of concrete masonry units. The screws will be located in the middle third of the width of the plate. A nut and washer must be tightened on each anchor bolt. There shall be a minimum of two bolts per plate section with one bolt located no more than 12 inches or less than seven bolt diameters from each end of the plate section.

The sole plates of interior bearing walls on monolithic slab foundations that are not part of a reinforced wall panel must be positively anchored with approved fasteners. Hearth plates and sole plates shall be protected against decay and termites where required.

Exceptions

• Walls 24 inches in total length or shorter. Connecting gusset wall panels will be anchored to the foundation with a minimum of one anchor bolt located in the center third of the plate section and attached to adjacent wall panels.
• Walls 12 inches in total length or shorter connecting wall panels with offset reinforcement to the foundation without anchor bolts. The wall should be attached to adjacent wall panels braced at the corners.

Foundation anchoring in seismic design categories C, D0, D1 and D2

The following requirements shall apply to wood span frame structures in seismic design categories D0, D1, and D2 and to houses in seismic design category C.

1. Appropriately sized cut washers will be permitted for anchor bolts on wall lines that do not contain braced wall panels. Interior reinforced wall plates must have anchor bolts spaced no more than 6 feet on center and located within 12 inches of the ends of each plate section when supported on a continuous foundation.
2. Bearing inner wall sole plates must have anchor bolts spaced no more than 6 feet on center and located within 12 inches of the ends of each plate section when supported on a continuous base.
3. The maximum spacing between anchor bolts will be 4 feet for buildings more than two stories in height.
4. The reinforced wall panel must be connected to the wooden foundation in accordance with the requirements for fixing the wall panel to the reinforced floor.

Footings on or adjacent to a slope

Placement of buildings and structures on or adjacent to slopes steeper than one vertical unit in three horizontal units (33.3% slope) must comply with Slope Foundation Clearance Section.

Construction clearance from ascending slopes

Subslope construction should be established a sufficient distance from the slope to provide protection against slope drainage, erosion, and surface failure. Where the existing slope is steeper than one unit vertical by one unit horizontal (100% slope), the tip of the slope will be assumed to be at the intersection of a horizontal plane drawn from the top of the base and a plane drawn tangent to the slope at an angle of 45 degrees (0.79 rad) to the horizontal.

Kickback of Footings from Downslope Surfaces

Footings on or adjacent to slope surfaces shall be founded on material with sufficient embedment and setback from the slope surface to provide vertical and lateral support for the footing without detrimental settlement.

When the slope is steeper than one unit vertical in one unit horizontal (100 percent slope), the required setback shall be measured from an imaginary plane 45 degrees (0.79 rad) to the horizontal, projected upward from the tip of the slope.

Foundation elevation

On qualified sites, the top of any exterior foundation must extend above the elevation of the street channel at the point of discharge or the entrance of an approved drainage device a minimum of 12 inches plus 2%.

Setbacks and alternative clearances

Setbacks and alternative clearances are allowed. The building official may require an investigation and recommendation by a qualified engineer to demonstrate that the intent of this section has been met. Such investigation should include consideration of the material, slope height, slope gradient, loading intensity, and erosion characteristics of the slope material.

Classification of expansive soils

Soils that meet the following four provisions will be considered expansive:

1. Plasticity index (Pl) of 15 or more, determined in accordance with ASTM D4318.
2. More than 10% of soil particles pass the No.200 sieve, determined in accordance with ASTM D422.
3. More than 10% of soil particles have a size of less than 5 micrometers, determined according to ASTM D422.
4. Expansion index greater than 20, determined in accordance with ASTM D4829.

Footings for wooden foundations

Footings for wood foundations shall be in accordance with Figure R403.1(2). The gravel will be washed and graded well. Maximum size stone should not exceed 3/4 inch. The gravel must be free of organic, clay or silty soils. The sand should be coarse, no smaller than 1/16 inch grain size, and should be free of organic, clay, or silty soils. Crushed stone should be no larger than 1/2 inch.

Shallow foundations protected from frost

For construction where the average monthly temperature is maintained at a minimum of 64°F, footings are not required to extend below the frost line when protected from frost by insulation. Frost-protected foundations should not be used for unheated spaces.

Materials used below grade for the purpose of insulating footings against frost shall be labeled as meeting ASTM C578.

Foundations adjacent to shallow foundations protected from frost.

Foundations adjoining shallow frost-protected foundations should be protected from frost as described in the previous titles.

Fijación a la estructura de losa sobre suelo sin calentar

Vertical wall insulation and horizontal insulation of shallow frost-protected foundations adjoining slab-on-grade foundations that do not have an average monthly temperature maintained at a minimum of 64°F must comply with a series of conditions. Vertical wall insulation will extend between the shallow frost-protected foundation and the adjacent slab foundation.

The required horizontal insulation must be continuous beneath the adjoining slab foundation and across any foundation walls adjacent to the shallow frost-protected foundation. When insulation passes through a foundation wall, it must be of a type that complies with this section and has a load capacity equal to or greater than the structural loads imposed by the building, or the building must be designed and constructed using beams. , lintels, overhangs or other means of transferring building loads so that the structural loads of the building are not supported by the insulation.

Exceptions

Where the shallow frost-protected foundation abuts the heated structure to form an interior corner, vertical insulation extending the length of the adjoining foundation is not required.

Protection of horizontal insulation underground.

Horizontal insulation placed less than 12 inches below the ground surface or that portion of horizontal insulation extending outward more than 24 inches from the edge of the foundation must be protected from damage.

This is done by using a concrete slab or asphalt paving on the ground surface directly above the insulation or by a cement board, underground graded plywood, or other approved materials placed below the ground directly above the surface. insulation top.

Sewer system

The final slope will be tilted according to what we have seen during these titles. In non-Group I soils, the gravel or crushed stone under the horizontal subgrade insulation must drain into daylight or into a sewer system. approved.

Protection against termites

Using plastic foam in areas of “very heavy” termite infestation probability may be a solution to this problem.

Crushed stone footings.

Clean crushed stone should be free of organic, clay or silty soils. Crushed stone must be angular in nature and comply with ASTM C33, with a maximum stone size not exceeding 1/2 inch and a minimum stone size not less than 1/16 inch.

Crushed stone footings for precast foundations shall be installed in accordance with Figure R403.4(1). Crushed stone footings will be consolidated using a vibrating plate at a maximum of 8 inch elevations. Crushed stone footings shall be limited to seismic design categories A, B and C.

Concrete Footings

This type of footings will be installed in accordance with the previous titles.

Foundation and retaining walls

Concrete and masonry foundation walls

Concrete foundation walls shall be selected and constructed in accordance with the provisions of Section concrete foundation walls. Masonry foundation walls shall be selected and constructed in accordance with the provisions of Section Design of Masonry Foundation Walls.

Required design

Concrete or masonry foundation walls shall be designed in accordance with accepted engineering practice when any of the following conditions exist:

1. The walls are subject to the hydrostatic pressure of groundwater.
2. Walls supporting more than 48 inches of unbalanced fill that have no permanent lateral support at the top or bottom.

Design of masonry foundation walls

All masonry foundation walls shall be designed and constructed in accordance with the provisions of this section or in accordance with the provisions of TMS 402/ACI 530/ASCE 5 standards.

Masonry foundation walls

Concrete masonry and clay masonry foundation walls shall be constructed as set forth in Table R404.1.1(1), R404.1.1(2), R404.1.1(3), or R404.1.1(4) and shall also be comply with all the provisions of the previous titles.

Concrete foundation walls

Concrete foundation walls supporting light frame walls shall be designed and constructed in accordance with the provisions of ACI 318, ACI 332, or PCA 100. When ACI 318, ACI 332, PCA 100 or the provisions of this section are used to design concrete foundation walls, project drawings, typical details and specifications are not to bear the stamp of the architect or engineer.

Reinforcement for foundation walls

Concrete foundation walls must be supported laterally at the top and bottom. Horizontal reinforcement shall be provided in accordance with Table R404.1.2(1). Vertical reinforcement shall be provided in accordance with Table R404.1.2(2), R404.1.2(3), R404.1.2(4), R404.1.2(5), R404.1.2(6), R404.1.2(7 ) or R404. 1.2(8).

Concrete foundation stem walls supporting above-grade concrete walls

Foundation stud walls supporting above-grade concrete walls shall be designed and constructed in accordance with this section.

1. The stem walls are not supported laterally at the top. Concrete stud walls that are not monolithic with slabs on the ground or are not laterally supported by slabs on the ground shall comply with this section. Where the unbalanced fill retained by the stem wall is less than or equal to 18 inches, the stem wall and supporting upper wall shall be provided with vertical reinforcement in accordance with the preceding Section.
2. Stem walls supported laterally at the top. Concrete stud walls that are monolithic with slabs on the floor or that are otherwise supported laterally by slabs on the floor must be reinforced vertically in accordance with the Section above for upper walls. Where the unbalanced fill retained by the stem wall is greater than 18 inches, the connection between the stem wall and the slab on the ground, and the portion of the slab on the ground that provides lateral support for the wall, shall be designed as according to the PCA 100 standard.

Concrete, concrete materials and forms

The materials used in the concrete, the concrete itself, and the forms must meet the requirements stipulated by ACI 318.

Compression resistance

The minimum specified compressive strength of concrete, f'c, must comply with the Section above called concrete and must not be less than 2,500 psi at 28 days in constructions assigned to Seismic Design Categories A, B or C and 3000 psi in buildings assigned to seismic design category D0, D1 or D2.

Concrete mixing and delivery

Concrete mixing and delivery must comply with ASTM C94 or ASTM C685.

Maximum Aggregate Size

The nominal maximum size of coarse aggregate shall not exceed one-fifth of the narrowest distance between the sides of the forms, or three-fourths of the clearance between reinforcing bars or between a bar and the side of the form.

Exceptions

When approved, these limitations will not apply when removable forms are used and the workability and consolidation methods allow the concrete to be placed without honeycombs or voids.

Concrete proportion and slump

These shall be established to provide that the concrete is easily worked into forms and around the reinforcement in ready-to-place conditions, without segregation or excessive bleeding. Slump of concrete placed in removable forms should not exceed 6 inches.

Exceptions

When approved, slump is permitted to exceed 6 inches for concrete mixtures that are resistant to segregation and that are in accordance with the form manufacturer's recommendations.

The slump of concrete placed in stay-in-place forms must exceed 6 inches. Concrete slump will be determined in accordance with ASTM C143.

Concrete consolidation

Concrete shall be consolidated by suitable means during placement and worked around embedded elements and reinforcement and into the corners of forms. When stay-in-place forms are used, the concrete will consolidate by internal vibration.

Exceptions

When concrete is approved for placement in stay-in-place forms, self-consolidating concrete mixtures with slumps equal to or greater than 8 inches that are specifically designed for placement without internal vibration do not need to be internally vibrated.

Form materials and form bonds

Forms shall be made of wood, steel, aluminum, plastic or other approved material suitable to support and contain concrete. The forms must provide sufficient strength to contain the concrete during the concrete placing operation.

Form ties shall be made of steel, solid plastic, foam plastic or other suitable material capable of resisting the forces created by the fluid pressure of fresh concrete.

Stay-in-Place Forms

Concrete forms that remain in place must comply with these guidelines.

1. Inner liner. Stay-in-place forms constructed of rigid plastic foam must be protected within the construction
2. Exterior wall covering. Stay-in-place forms constructed of rigid foam plastics must be protected from sunlight and physical damage by the application of an approved exterior wall covering that complies with the Florida residential building code.
3. Termite protection. In areas where the likelihood of termite infestation is "very strong," subgrade foam plastic insulation should be permitted in foundation walls.
4. ICF flat wall system forms must comply with ASTM E2634.

Reinforcement

Steel reinforcement

Steel reinforcement must meet the requirements of ASTM A615, A706, or A996. ASTM A996 bars produced from rail steel shall be Type R. In construction assigned to Seismic Design Categories A, B, or C, the minimum yield strength of the reinforcing steel shall be 40,000 psi (Grade 40).

In construction assigned to seismic design category D0, D1, or D2, reinforcing steel must meet the requirements of ASTM A 706 for low-alloy steel with a minimum yield strength of 60,000 psi (Grade 60).

Location of reinforcement in the wall

The center of vertical reinforcement in basement walls determined from Tables R404.1.2(2) through R404.1.2(7) shall be located on the centerline of the wall. Regardless of the table used to determine vertical wall reinforcement, the center of the steel should not vary from the specified location by more than one; 10% of wall thickness and 1/8 in. Horizontal and vertical reinforcement should be located on the foundation walls to provide minimum coverage.

Wall openings

Vertical wall reinforcement required by the preceding Section that is interrupted by wall openings shall have additional vertical reinforcement of the same size placed within 12 inches of each side of the opening.

Support and cover

Steel reinforcement in concrete cast against the ground must have a minimum cover of 3 inches. The minimum cover for reinforcement in cast concrete in removable forms that will be exposed to soil or weather shall be 1-1/2 inches for No. 5 and smaller bars AND 2 inches for No. 6 and larger bars.

For concrete mold in removable forms that will not be exposed to soil or weather, and for concrete mold in forms that remain in place, the minimum cover should be 3/4 inch. The negative tolerance for the cover must not exceed the lesser of one-third of the required cover or 3/8 inch.

Back Splices

The vertical and horizontal reinforcement of the wall will be as long as possible. When splices are necessary in reinforcement. The maximum space between non-contacting parallel bars in a lap splice shall not exceed the lesser of one-fifth of the required lap length and 6 inches.

Alternative Degree of Reinforcement and Spacing

Where the tables in Section R404.1.3.2 specify vertical wall reinforcement based on minimum bar size and maximum spacing, which are based on Grade 60 steel reinforcement, bars of different sizes or bars made of a different grade of steel, provided that an equivalent area of steel per linear foot of wall is permitted.

Reinforcement of construction joints

Construction joints in foundation walls must be made and located so as not to affect the strength of the wall. Construction joints in smooth concrete walls, including walls that must have not less than 4 bars at 48 inches on center, must be located at lateral support points, and a minimum of one No. 4 bar must extend through the joint of construction with a spacing not to exceed 24 inches on center.

Construction joint reinforcement must have a minimum embedment of 12 inches on both sides of the joint. Construction joints in reinforced concrete walls should be located in the middle third of the span between the lateral supports, or located and constructed as required for joints in smooth concrete walls.

Exceptions

The use of vertical wall reinforcement required by the Florida residential building code is permitted in lieu of construction joint reinforcement, provided the spacing does not exceed 24 inches, or the combination of wall reinforcement and No. bars. 4 described above does not exceed 24 inches.

Exterior wall coverings

Requirements for the installation of masonry veneers, stucco and other wall coverings on the exterior of concrete walls and other construction details not covered in this section shall comply with the requirements of the Florida residential building code.

Requirements for seismic design category C

Concrete foundation walls supporting higher grade concrete walls in townhouses assigned to Seismic Design Category C shall comply with ACI 318, ACI 332, or PCA 100.

Seismic design category D0, D1 or D2

Masonry foundation walls

In constructions assigned to seismic design category D0, D1 or D2, masonry foundation walls will comply with the following:

1. Wall height should not exceed 8 feet.
2. Unbalanced fill height should not exceed 4 feet.
3. The minimum nominal thickness for simple masonry foundation walls should be 8 inches.
4. Masonry stud walls shall have a minimum vertical reinforcement of one No. 4 bar located a maximum of 4 feet on center in grouped cells. The vertical reinforcement must be tied to the horizontal reinforcement in the footings.

Foundation walls, supporting more than 4 feet of unbalanced fill or exceeding 8 feet in height, shall be constructed in accordance with Table R404.1.1(2). Masonry foundation walls must have two No.4 horizontal bars located in the top 12 inches of the wall.

Concrete foundation walls

For buildings assigned to Seismic Design Category D0, D1, or D2, concrete foundation walls supporting light frame walls shall comply with this section, and concrete foundation walls supporting above-grade concrete walls shall comply with this section. with ACI 318, ACI 332, or PCA 100. In addition to horizontal reinforcement, plain concrete walls supporting span frame walls must comply with the following:

• Wall height should not exceed 8 feet.
• Unbalanced fill height should not exceed 4 feet.
• The minimum thickness for smooth concrete foundation walls shall be 7.5 inches, except that 6 inches is permitted where the maximum wall height is 4 feet, 6 inches.

Foundation walls less than 7.5 inches thick, supporting more than 4 feet of unbalanced fill, or exceeding 8 feet in height, shall be provided with horizontal reinforcement and vertical reinforcement.

Masonry wall thickness

Masonry foundation walls shall not be less than the thickness of the supported wall, except that masonry foundation walls of at least 8 inches nominal thickness shall be permitted under brick veneer frame walls and under a 10-inch wide cavity walls where the total height of the supported wall, including gables, is not more than 20 feet.

Concrete wall thickness

The thickness of the concrete foundation walls will be equal to or greater than the thickness of the wall in the previous section.

When the thickness of a concrete foundation wall is reduced to provide a shelf for supporting the masonry veneer, the reduced thickness must be equal to or greater than the wall thickness of the previous section. Vertical reinforcement for the foundation wall shall be based on Table R404.1.2(8) and located in the wall. Vertical reinforcement will be based on the thickness of the thinnest portion of the wall.

Exceptions

When the height of the reduced thickness portion measured at the bottom of the floor assembly or top sill plate is less than or equal to 24 inches and the thickness reduction does not exceed 4 inches, the vertical reinforcement is permitted to be based in the thickest portion of the wall.

Pier foundations and curtain walls

The use of curtain wall foundations shall be permitted to support the construction of span frames no more than two stories in height, provided the following requirements are met:

• All load-bearing walls will be placed on continuous concrete footings placed integrally with the exterior wall footings.
• The minimum actual thickness of a load-bearing masonry wall shall be not less than 4 inches nominal or 33/8 inches actual thickness, and shall be integrally joined with spaced piers.
• The maximum height of a 4-inch masonry foundation wall supporting wood-framed walls and floors should not be greater than 4 feet.
• The anchoring must be in accordance with the anchors Section seen above.
• Unbalanced fill for 4-inch foundation walls should not exceed 24 inches for solid masonry or 12 inches for hollow masonry.
• In seismic design categories D0, D1 and D2, prescriptive reinforcement will be provided in horizontal and vertical directions. Provide a minimum horizontal bond reinforcement of two No. 9 gauge wires spaced not less than 6 inches apart or one 1/4-inch wire 10 inches on center vertically. Provide minimum vertical reinforcement of a No. 4 bar 48 inches on center horizontally grouped in place.

Height above final level

Concrete and masonry foundation walls must extend above the finished grade adjacent to the foundation at all points a minimum of 4 inches where masonry veneer is used and a minimum of 6 inches elsewhere.

Filling placement

The filler should be placed against the wall until the wall has sufficient strength and has been anchored to the floor above, or has been sufficiently reinforced to prevent damage from the filler.

Exception

Bracing is not required for walls supporting less than 4 feet of unbalanced fill.

Rubble stone masonry

Rubble stone masonry foundation walls must have a minimum thickness of 16 inches, must not support unbalanced fill more than 8 feet in height, must not support a soil pressure greater than 30 pounds per square foot, and must not must be built in Seismic Design Categories D0, D1, D2 or semi-detached houses in Seismic Design Category C.

Isolated masonry pillars

Isolated masonry pillars shall be constructed in accordance with general masonry construction requirements. Hollow masonry pillars shall have a minimum nominal thickness of 8 inches, with a nominal height not exceeding four times the nominal thickness and a nominal length not exceeding three times the nominal thickness.

Where hollow masonry units are solidly filled with concrete or grout, columns shall be permitted to have a nominal height not exceeding ten times the nominal thickness.

Spring cover

Hollow masonry piers shall be covered with 4 inches of solid masonry or concrete, a masonry cap block, or shall have top layer cavities filled with concrete or grout.

Masonry pillars supporting floor beams

Piers supporting beams for interior bearing walls shall have a minimum nominal dimension of 12 inches and a maximum height of 10 feet from the top of the footing to the bottom of the threshold plate or beam.

Piers supporting beams for exterior bearing walls shall have a minimum nominal dimension of 12 inches and a maximum height of 4 feet from the top of the footing to the bottom of the threshold plate or beam. Beams and sills must be anchored to the pier or footing.

Masonry pillars supporting reinforced wall panels

Masonry piers supporting reinforced wall panels shall be designed in accordance with accepted engineering practice.

Seismic design of masonry columns

Masonry piers in homes located in seismic design category D0, D1 or D2, and townhouses in seismic design category C, shall be designed in accordance with accepted engineering practice.

Masonry piers in flood hazard areas

Masonry piers for homes in flood hazard areas must be designed in accordance with the instructions of Chapter 3 of the Florida Residential Building Code.

Identification

Loader lumber shall be identified with the grade mark of a lumber grading or inspection agency that has been approved by an accreditation body that complies with DOC PS 20. Structural wood panels must comply with DOC PS 1 or DOC PS 2.

Bolt size

Posts used in the foundation walls will be 2-inch by 6-inch members. When spaced 16 inches on center, a wood species with an Fb value of not less than 1,250 pounds per square inch as listed in ANSI A WC NDS shall be used.

Filling height

For wood foundations that are not designed and installed in accordance with A WC PWF, the height of fill against a foundation wall should not exceed 4 feet.

Filling

Wood foundation walls will not be filled in until the basement floor and first floor have been built or the walls have been reinforced. For crawl space construction, fill or bracing must be installed on the inside of the walls before fill is placed on the outside.

Drainage and moisture protection

Wood foundation basements must be drained and moisture-proofed in accordance with Section wood foundations, detailed later.

Fixation

The wood structural panel base wall covering should be attached to the frame.

Wooden sill plates

Wood sill plates must be a minimum of 2 inches by 4 inches of nominal lumber.

Retaining walls

Top-only walls that retain more than 48 inches of unbalanced fill, or retaining walls more than 24 inches in height that resist lateral loads in addition to soil, shall be designed in accordance with accepted engineering practice. to ensure stability against tipping, sliding, excessive base pressure and water uplift. Retaining walls shall be designed for a safety factor of 1.5 against lateral sliding and overturning.

Precast concrete foundation walls

Design

Precast concrete foundation walls shall be designed in accordance with accepted engineering practice. The design and fabrication of precast concrete foundation wall panels must comply with material requirements or ACI 318.

Precast Concrete Foundation Design Drawings

Design drawings for precast concrete foundation walls must be submitted to the building official and approved prior to installation. The drawings will include, at a minimum, the following information:

1. Load design as appropriate.
2. Footing and material design.
3. Concentrated loads and their application points.
4. Soil bearing capacity.
5. Maximum allowable total uniform load.
6. Seismic design category.
7. Basic wind speed.

Foundation drainage

Concrete or masonry foundations

Drains must be provided around concrete or masonry foundations that retain soil and enclose habitable or usable spaces located below grade. Drainage tile, gravel or crushed stone drains, perforated pipe or other approved systems or materials shall be installed in or below the area to be protected and discharged by gravity or mechanical means into an approved drainage system.

Gravel or crushed stone drains shall extend not less than l foot beyond the outside edge of the footing and 6 inches above the top of the footing and be covered with an appropriate filter membrane material. The top of the open joints of the drainage tiles will be protected with strips of construction paper.

Exceptions

A drainage system is not required when the foundation is installed in well-drained soils or gravel mix soils according to the Unified Soil Classification System, Group I soils.

Precast concrete foundation

Precast concrete walls that retain soil and enclose habitable or usable spaces located below grade level that rest on crushed stone footings must have a perforated drainage pipe installed below the base of the wall on the interior or exterior side of the wall, not less than 1 foot beyond the edge of the wall.

Cimientos de madera

Wood foundations enclosing habitable or usable spaces located below grade must be properly drained in accordance with the specifications explained above.

Base

A porous layer of gravel, crushed stone, or coarse sand with a minimum thickness of 4 inches should be placed beneath the basement floor. Provision will be made for automatic drainage of this layer and the gravel footings or crushed stone wall.

Vapor Retarder

A 6 mil thick polyethylene vapor retarder will be applied over the porous layer with the basement floor constructed over the polyethylene.

Sistema de drenaje

In soils other than Group I, a sump shall be provided to drain the porous layer and footings. The sump must be no less than 24 inches in diameter or 20 inches square, must extend no less than 24 inches below the bottom of the basement floor, and must be capable of positive gravity or mechanical drainage to remove accumulated water.

Waterproof and cushioning foundation

Waterproofing of concrete and masonry foundations

Foundation walls that retain soil and enclose interior spaces and floors below grade shall be moisture proof from the top of: (a) the top of the footing or (b) 6 inches below the top of the basement floor, to the final level.

Masonry walls should have no less than 3/8 inch of Portland cement applied to the outside of the wall. Parging must be damp proofed in accordance with one of the following:

1. Bituminous coating.
2. Three pounds per square yard (1.63 kg/m2) of modified acrylic cement.
3. A one-eighth inch surface bonding cement layer that meets ASTM C887.
4. Any material permitted for waterproofing.
5. Other approved methods or materials.

Exceptions

Interlocking of unit masonry walls is not required when a material is approved for direct application to masonry.

Concrete walls should be waterproofed by applying any of the waterproofing materials listed or any of the waterproofing materials listed above to the exterior of the wall.

Waterproofing of concrete and masonry foundations

In areas where a high water table or other severe ground water conditions are known to exist, exterior foundation walls that retain soil and enclose interior spaces and floors below grade should be waterproofed from the top from: (a) the top of the foundation or (b) 6 inches below the top of the basement floor, to the final grade. Walls must be waterproofed in accordance with one of the following:

• Two-layer filters with hot mop.
• Fifty-five pound roll roofing
• Six thousand polyvinyl chloride.
• Six thousand polyethylene.
• Forty thousand polymer modified asphalt.
• Sixty thousand flexible polymer cement.
• One-eighth inch fiber-reinforced cement-based waterproof coating.
• Sixty thousand, solvent-free, liquid-applied synthetic rubber.

Exceptions

Products based on organic solvents such as hydrocarbons should not be used for ICF walls with expanded polystyrene form material. Plastic roofing cements, acrylic coatings, latex coatings, mortars, and ICF wall sealing patches are permitted.

Cold-set asphalt or hot-set asphalt must comply with Type C of ASTM D449. Hot asphalt must be applied at a temperature of less than 200°F.

All joints in membrane waterproofing must be lapped and sealed with an adhesive compatible with the membrane.

Waterproofing for wooden foundations

Wood foundations enclosing habitable or usable spaces located below grade shall be protected from moisture in accordance with the preceding Sections.

Sealed panel joint

Plywood panel joints in foundation walls shall be sealed along their entire length with a caulking compound capable of producing a moisture-tight seal under the conditions of temperature and moisture content under which it will be applied and used.

Below Grade Moisture Barrier

A 6-mil thick polyethylene film should be applied over the below-grade portion of the exterior foundation walls prior to backfilling. The top edge of the polyethylene film will be attached to the liner to form a seal.

Grade-level film areas shall be protected from mechanical damage and exposure by a pressure preservative-treated lumber or plywood strip attached to the wall several inches above the finished grade level and extending approximately 9 inches below level.

Porous filler

The space between the excavation and the foundation wall shall be filled with the same material used for footings, to a height of 1 foot above the footing for well-drained sites, or half the total height of fill for poorly drained sites. The porous fill will be covered with 30-pound strips of asphalt paper to allow water infiltration and prevent infiltration of fine soils.

Filling

The rest of the excavated area will be filled with the same type of soil that was removed during the excavation.

Precast Concrete Foundation System for Roof Dams

To be waterproofed, precast concrete foundation walls enclosing habitable or usable spaces located below grade level shall be moisture-proofed in accordance with the sections seen above.

Sealed panel joints

Precast concrete foundation panel joints shall be sealed to full height with a sealant complying with ASTM C920, Type S or M, Grade NS, Class 25, Use NT, M or A. Joint sealant shall be installed in accordance with the manufacturer's instructions.

Columns

Steel column protection

All surfaces (interior and exterior) of steel columns must receive a coat of corrosion-inhibiting paint.

Structural requirements

Columns must be restrained to prevent lateral displacement at the lower end. Wood columns must have a nominal size of no less than 4 inches by 4 inches. Steel columns shall have Schedule 40 pipe not less than 3 inches in diameter manufactured in accordance with ASTM A53 Grade B.

Exceptions

In seismic design categories A, B, and C, columns not more than 48 inches high on a pier or footing are exempt from the lower end lateral displacement requirement within substory areas enclosed by a continuous foundation.

Underfloor space

Ventilation

The crawl space between the bottom of the floor joists and the ground beneath any building (except the space occupied by a basement) must have ventilation openings through the foundation walls or exterior walls. The minimum net area of ventilation openings shall be not less than 1 square foot per 150 square feet of crawl space, unless the floor surface is covered by a Class I vapor retarder material.

When a Class I vapor retarder material is used, the minimum net area of ventilation openings shall be not less than 1 square foot for every 1,500 square feet of crawl space area. One of those vents should be 3 feet from each corner of the building.

Ventilation openings under the floor

The minimum net area of ventilation openings shall be not less than 1 square foot for every 150 square feet of subfloor area. A ventilation opening should be 3 feet from each corner of the building. Ventilation openings must be covered for their height and width with any of the following materials:

1. Perforated sheet metal plates not less than 0.070 inches thick.
2. Expanded sheet metal plates not less than 0.047 inch thick.
3. Cast iron grate.
4. Extruded brick ventilation grilles.
5. 0.035 inch or heavier wire hardware cloth.
6. Corrosion-resistant wire mesh, with a minimum dimension of 1/8 inch thick.

Exceptions

The total area of ventilation openings shall be reduced to 1/1,500 of the subfloor area where the floor surface is covered with an approved Class I vapor retarder material and the required openings are positioned to provide cross ventilation of the space.

Unventilated crawl space

Access to all spaces below the floor

Access openings through the floor must be a minimum of 18 inches by 24 inches. Openings through a perimeter wall shall be no less than 16 inches by 24 inches. When any part of the access through the wall is below grade.

The bottom of the area must be below the threshold of the access opening. Through-wall access openings shall not be located under a residence door.

Removal of debris

The slope below the floor will be cleared of all vegetation and organic material. All materials used to place concrete will be removed before the building is occupied or used for any purpose.

Finished degree

The finished grade of the subfloor surface shall be permitted to be located at the bottom of the footings; However, where there is evidence that the water table may rise up to 6 inches from the finished floor at the building perimeter or where there is evidence that surface water does not drain easily from the construction site, the grade in the crawl space should be be as high as the finished exterior grade, unless an approved drainage system is provided.

Annex of tables and figures