+---
+title: Grouted Column Base Plates and Bearing Plates
+category: Structural / Concrete
+toc_depth: 3
+description: >
+ When to use: Installation, material selection, and acceptance of grouted column base plates and bearing plates on concrete foundations, piers, and pedestals, where a cementitious or epoxy non-shrink grout layer fills the void between a leveled steel plate and the concrete substrate. Covers structural steel column bases, equipment bearing plates, and beam bearing plates on commercial, industrial, and institutional buildings, including leveling, formwork, grout selection and placement, curing, anchor rod torquing, and field verification.
+ Not intended for: Non-shrink grout material supply and acceptance testing alone (use [[sync/non-shrink-grout]]); structural steel column, beam, and connection fabrication and erection (use [[sync/structural-steel-framing]]); concrete footing, pier, and pedestal design and concrete materials (use [[sync/shallow-foundations]]); anchor rod design, fabrication, grades, and setting templates (use [[sync/structural-steel-anchor-bolts]]); dynamic machine and rotating-equipment foundation grouting under vibrating loads (follows ACI PRC-351.1); epoxy injection crack repair; and setting of precast members on grout pads.
+---
+
+# Scope {toc}
+
+## This standard covers the leveling, formwork, grouting, curing, and acceptance of steel base plates and bearing plates set on concrete with a non-shrink grout bed.
+
+### This standard governs the work of filling the space between a leveled steel base plate or bearing plate and its concrete support with cementitious or epoxy non-shrink grout so that bearing loads transfer uniformly from steel to concrete. The grout bed is a structural, load-bearing element that carries the full base plate bearing reaction into the concrete pedestal; voids, low strength, or delamination in the grout are bearing defects, not cosmetic ones, and the work is inspected and tested on that basis. {note}
+
+### This standard applies wherever the structural drawings show a grouted base plate or bearing plate condition, regardless of project type or occupancy. {note}
+
+### Base plate fabrication, column erection, and anchor rod setting are performed under their own standards and are coordinated with, but not governed by, this section. {note}
+
+### Setting, leveling, formwork, grout placement, curing, and post-grout anchor rod torquing shall be performed in accordance with this standard and the approved grout manufacturer's published instructions.
+
+### The grout type, grade, grout-space thickness, and anchor rod torque values shall be as shown on the structural drawings and shall be established before base plate fabrication.
+
+### Responsibility for setting and leveling the plate and responsibility for placing the grout shall be assigned in the Contract Documents.
+
+### A single party shall be made responsible for the completed, accepted grout bed.
+
+### The split of work between the steel erector who sets and levels the plate and the concrete trade who places the grout is a frequent source of gaps; clear assignment in the Contract Documents closes the gap. {note}
+
+# Referenced Standards {toc}
+
+## Materials, installation, and acceptance shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+
+## Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
+| Standard | Title |
+|----------|-------|
+| ASTM C1107/C1107M | Packaged Dry, Hydraulic-Cement Grout (Nonshrink) |
+| ASTM C109/C109M | Compressive Strength of Hydraulic Cement Mortars |
+| ASTM C827/C827M | Change in Height at Early Ages of Cylindrical Specimens of Cementitious Mixtures |
+| ASTM C939/C939M | Flow of Grout for Preplaced-Aggregate Concrete (Flow Cone Method) |
+| AISC 360 | Specification for Structural Steel Buildings (Section J8, bearing on concrete) |
+| AISC Design Guide 1 | Base Plate and Anchor Rod Design |
+| AISC 303 | Code of Standard Practice for Steel Buildings and Bridges |
+| ACI 318 | Building Code Requirements for Structural Concrete |
+| ACI PRC-351.1 | Report on Grouting between Foundations and Bases for Support of Equipment and Machinery |
+
+## ASTM C1107 is the controlling material standard for packaged cementitious non-shrink grout and defines the Grade A, B, and C volume-change classes referenced throughout this standard. {note}
+
+## AISC 360 Section J8 establishes the bearing strength of concrete under the plate, and AISC Design Guide 1 is the primary engineering reference for plate thickness, grout-space thickness, and grout hole sizing. {note}
+
+## ACI PRC-351.1 is the most widely cited guidance on grout consistency, minimum thickness relative to flow length, substrate preparation, and anchor bolt torquing sequence; although it is written around equipment bases, its placement guidance is directly applicable to structural building base plates. {note}
+
+# Submittals {toc}
+
+## Action submittals shall be provided before grout is delivered to the site.
+
+### The Contractor shall submit the following action submittals for review:
+
+- Product data for each grout product, listing type (cementitious or epoxy), ASTM C1107 grade where applicable, and published compressive strength at 1, 3, 7, and 28 days.
+- Manufacturer's published mixing, placement, and curing instructions, including water content limits for each consistency and the allowable placement temperature range.
+- Grout space and leveling details showing grout thickness, leveling method, grout hole locations on base plates wider than 24 in., and form configuration.
+- A cold-weather and hot-weather grouting plan where placement is anticipated outside the manufacturer's published temperature range.
+
+```datasheet
+label: Action submittals required
+type: checkbox
+options:
+ - Grout product data (type, grade, strength curve)
+ - Manufacturer mixing/placement/curing instructions
+ - Grout space and leveling details
+ - Grout hole layout on base plates wider than 24 in.
+ - Cold-weather / hot-weather grouting plan
+default:
+ - Grout product data (type, grade, strength curve)
+ - Manufacturer mixing/placement/curing instructions
+ - Grout space and leveling details
+```
+
+## Informational submittals document field conditions and test results during grouting.
+
+### The Contractor shall submit the following informational submittals:
+
+- Grout compressive strength test reports for cubes cast during placement and tested per ASTM C109.
+- Flow cone test results per ASTM C939 for fluid grouts where required by the Engineer.
+- Field reports documenting substrate preparation, ambient and grout temperature, and form inspection for each grouting operation.
+- Anchor rod torque records confirming torque was applied after the grout reached the required strength.
+
+```datasheet
+label: Informational submittals required
+type: checkbox
+options:
+ - Grout compressive strength reports (ASTM C109)
+ - Flow cone test results (ASTM C939)
+ - Field reports (substrate, temperature, forms)
+ - Anchor rod torque records
+default:
+ - Grout compressive strength reports (ASTM C109)
+ - Field reports (substrate, temperature, forms)
+ - Anchor rod torque records
+```
+
+## Closeout submittals confirm the installed grout meets the specified strength.
+
+### The Contractor shall submit the following closeout submittals:
+
+- 28-day compressive strength reports for all grout placed, correlated to base plate locations.
+- A record of any grout placement that failed acceptance and the approved corrective action taken.
+
+```datasheet
+label: Closeout submittals required
+type: checkbox
+options:
+ - 28-day grout compressive strength reports by location
+ - Nonconformance and corrective action records
+default:
+ - 28-day grout compressive strength reports by location
+```
+
+# Quality Assurance {toc}
+
+## Grout placement is a specialized operation that determines whether the base plate bears uniformly; qualified personnel and independent testing are required.
+
+### Grout shall be mixed and placed by personnel experienced in non-shrink grouting and familiar with the specific product's published instructions.
+
+### The same grout product and grade shall be used for all base plates of a given type unless the Engineer of Record approves a substitution in writing.
+
+### A grout product shall not be substituted after submittal approval without the written approval of the Engineer of Record.
+
+### Grout compressive strength specimens shall be cast during each grouting operation in accordance with ASTM C1107 and tested per ASTM C109.
+
+### Because the grout bed is load-bearing, the absence of test specimens leaves no basis to accept or reject the work; specimens are required for every placement, not sampled across the project. {note}
+
+### A minimum of one set of grout cube specimens shall be cast for each day of grouting and for each distinct grout product or grade placed.
+
+### Grout cube specimens shall be field-cured under conditions matching the base plates they represent and tested at the ages required by the Engineer.
+
+### The Engineer of Record shall be notified before grouting of any base plate designated for special inspection so that substrate preparation and placement can be observed.
+
+### Special inspection of base plate grouting, where required by the building code or the Contract Documents, shall verify substrate condition, grout consistency, fill completeness, and curing. {note}
+
+# Environmental and Service Conditions {toc}
+
+## Ambient and substrate temperature at the time of placement control grout strength gain and the risk of bond failure.
+
+### Cementitious non-shrink grout shall be placed only when the ambient and substrate temperature is within the manufacturer's published range, typically 40°F to 90°F.
+
+### Epoxy non-shrink grout shall be placed only when the ambient and substrate temperature is within the manufacturer's published range, typically 50°F to 90°F.
+
+### Epoxy grout cure is strongly temperature dependent: cold placement retards cure and may prevent bond, while hot placement accelerates set and shortens working time, so epoxy is never placed outside its range without a temperature plan. {note}
+
+### Where placement is required outside the published temperature range, the approved cold-weather or hot-weather grouting plan shall be in effect.
+
+### The grout, the base plate, and the concrete substrate shall be conditioned to within the placement temperature range and maintained there through initial cure.
+
+```datasheet
+label: Placement ambient temperature range
+type: range
+unit: °F
+min: 40
+max: 90
+step: 5
+```
+
+## The grout must be protected from drying, freezing, and load until it reaches the required strength.
+
+### Placed grout shall be protected from rapid moisture loss by wet curing or by a curing method compatible with the grout manufacturer's instructions.
+
+### Cementitious grout shall be wet cured with saturated burlap, water, or a manufacturer-approved curing compound for the manufacturer's published minimum period.
+
+### A curing compound shall not be used where the manufacturer prohibits it for the selected grout product.
+
+### Grout shall be protected from freezing until it reaches the manufacturer's published minimum strength for cold-weather protection.
+
+### Structural load shall not be applied to the grout bed until it has reached the minimum strength or cure time specified for loading.
+
+# Grout Material and Type {toc}
+
+## Grout type and grade are selected to match bearing demand, exposure, and placement geometry, and shall be fixed on the structural drawings.
+
+### The grout type and grade shall be as shown on the structural drawings and shall be established before base plate fabrication.
+
+### Cementitious non-shrink grout shall comply with ASTM C1107 and shall be a packaged, dry, prepackaged product requiring only the addition of water at the site.
+
+### Cementitious grout shall not be extended with site-added aggregate except where the manufacturer permits aggregate extension for pours exceeding the product's single-lift thickness limit.
+
+### Epoxy non-shrink grout, where specified, shall be a two-component product mixed and placed strictly in accordance with the manufacturer's instructions.
+
+### Epoxy grout is selected for high chemical exposure, vibration, or very high bearing demand, reaching compressive strengths well above cementitious grout but at higher cost and with strict temperature control; it is not the default for ordinary column bases. {note}
+
+```datasheet
+label: Grout type
+type: radio
+options:
+ - Cementitious non-shrink (ASTM C1107)
+ - Epoxy non-shrink (two-component)
+default: Cementitious non-shrink (ASTM C1107)
+```
+
+## ASTM C1107 grade and minimum compressive strength shall match the bearing demand the plate imposes.
+
+### The grout grade shall be selected so the grout strength is at least equal to, and preferably 1.5 to 2 times greater than, the specified concrete substrate strength.
+
+### Selecting a low grade where high bearing stress is present is a common error; the Engineer of Record confirms that the grade and minimum strength match the design bearing demand, not just the volume-change requirement. {note}
+
+### Cementitious non-shrink grout shall have a minimum 28-day compressive strength of 5000 psi per ASTM C1107 unless a higher strength is shown.
+
+### Where the structural drawings call for high bearing demand or early strength, Grade C grout with a minimum 28-day compressive strength of 8000 psi shall be provided.
+
+```datasheet
+label: Grout grade and minimum 28-day compressive strength
+type: radio
+options:
+ - "Grade A or B, 5000 psi minimum"
+ - "Grade C, 8000 psi minimum"
+ - "Epoxy, 10000 psi minimum"
+default: "Grade A or B, 5000 psi minimum"
+```
+
+```datasheet
+label: Specified minimum grout 28-day compressive strength
+type: range
+unit: psi
+min: 5000
+max: 14000
+step: 500
+```
+
+## Grout consistency is selected to fill the grout space completely without segregation, based on the space geometry and access.
+
+### Dry-pack consistency is a stiff, hand-rammed mix used for small plates with limited access; flowable and fluid consistencies are pumped or poured under larger plates and are the common choice for column bases. {note}
+
+### Grout consistency shall be selected to completely fill the grout space without segregation, voids, or bleed.
+
+### Fluid grout, where used, shall meet a flow cone efflux time of 20 to 30 seconds per ASTM C939 unless the manufacturer specifies otherwise.
+
+### Water shall not be added to a cementitious grout beyond the maximum published for the selected consistency.
+
+### Adding water beyond the published maximum to improve flow reduces compressive strength and increases bleed; consistency is controlled by selecting the right mix, not by overwatering. {note}
+
+```datasheet
+label: Grout consistency
+type: radio
+options:
+ - Dry-pack (stiff)
+ - Flowable
+ - Fluid (pumped or poured)
+default: Flowable
+```
+
+# Grout Space and Base Plate Configuration {toc}
+
+## The grout space thickness must be coordinated with the structural drawings before the plate is fabricated and the anchor rods are set.
+
+### The grout-space thickness, measured from the top of concrete to the underside of the base plate, shall be as shown on the structural drawings.
+
+### A typical grout space is 1 to 2 in., with 1.5 in. the common case; the minimum is 1 in. and a single lift of standard cementitious grout without aggregate extension is generally limited to 3 in. {note}
+
+### ACI PRC-351.1 relates minimum grout thickness to flow length, recommending at least 1 in. for a 1 ft flow length plus 0.5 in. for each additional foot the grout must travel under the plate. {note}
+
+### The grout space shall not be less than 1 in. at any point under the bearing area unless a thinner space is shown and approved.
+
+### Grout thickness exceeding 3 in. in a single lift shall use an aggregate-extended grout where the manufacturer permits extension, or shall be placed in multiple lifts per the manufacturer's instructions.
+
+### When the grout thickness is not coordinated before fabrication, the fabricator cuts the plate and the anchor rods are set to the wrong elevation, leaving the plate too high or too low; the thickness is therefore fixed on the drawings before fabrication begins. {note}
+
+```datasheet
+label: Grout space thickness (top of concrete to underside of plate)
+type: range
+unit: in
+min: 1
+max: 3
+step: 0.25
+default: 1.5
+```
+
+## Grout holes in the base plate allow grout to fill and vent under wide plates.
+
+### Grout cannot reliably reach the center of a plate wider than about 24 in. by side flow alone; fill and vent holes through the plate are required so grout rises through the plate and air escapes. {note}
+
+### Base plates wider than 24 in., or plates with shear lugs, shall be provided with grout holes.
+
+### Grout holes shall be 2 to 3 in. in diameter, thermally cut, and located so that grout fills the entire bearing area and air vents from beneath the plate.
+
+### Grout hole size and location shall be shown on the approved shop drawings.
+
+### Grout shall continue to be placed through the holes until grout emerges from all holes and from the perimeter, confirming complete fill.
+
+```datasheet
+label: Grout holes in base plate
+type: radio
+options:
+ - "None (plate 24 in. or narrower, no shear lug)"
+ - "Provided (plate wider than 24 in. or with shear lug)"
+default: "None (plate 24 in. or narrower, no shear lug)"
+```
+
+```datasheet
+label: Grout hole diameter
+type: range
+unit: in
+min: 2
+max: 3
+step: 0.5
+default: 2.5
+```
+
+# Substrate and Plate Preparation {toc}
+
+## The concrete substrate must be roughened, clean, and saturated surface dry so the grout bonds and gains full strength.
+
+### A smooth, troweled concrete top provides inadequate bond; roughening the pedestal top is a construction requirement, not a recommendation, and is verified before grouting. {note}
+
+### The top of the concrete pedestal or footing shall be roughened to a minimum amplitude of approximately 1/4 in. before grouting.
+
+### All laitance, oil, curing compound, dust, and loose material shall be removed from the concrete surface before grouting.
+
+### The concrete surface shall be brought to a saturated surface dry (SSD) condition immediately before grouting, with no standing water in the grout space.
+
+### Dry concrete wicks mixing water out of the grout, lowering strength and causing delamination at the interface; the inspector verifies the SSD condition before placement begins. {note}
+
+### The underside of the base plate and the exposed anchor rods within the grout space shall be free of oil, paint, grease, and other bond-breaking material.
+
+```datasheet
+label: Concrete substrate roughening amplitude
+type: range
+unit: in
+min: 0.125
+max: 0.375
+step: 0.0625
+default: 0.25
+```
+
+```datasheet
+label: Substrate moisture condition at placement
+type: radio
+options:
+ - Saturated surface dry (SSD), no standing water
+ - Dry (epoxy grout only, per manufacturer)
+default: Saturated surface dry (SSD), no standing water
+```
+
+# Leveling and Setting {toc}
+
+## The base plate is brought to line and grade with leveling nuts or shims before grouting, and the method must be defined on the drawings.
+
+### Leveling nuts thread on the anchor rods below the plate and remain in place permanently; steel shims and wedges are set between the plate and concrete and may or may not be removed after grouting, depending on the design. {note}
+
+### The base plate leveling method shall be as shown on the structural drawings.
+
+### The base plate shall be set to the line, grade, and level tolerances of AISC 303 before grouting.
+
+### Where leveling nuts are used, they shall remain in place permanently.
+
+### Where leveling nuts are used, they shall be locked with a jam nut or tack welded after final anchor rod torquing where required by the drawings.
+
+### Where steel shims or wedges are used, the drawings shall state whether they are removed after the grout cures or left permanently in place.
+
+### Leaving steel shims in place without full grout encapsulation creates corrosion paths and interrupts uniform bearing; the Contract Documents shall state whether shims are removed or left permanently in place. {note}
+
+### Shims left permanently in place shall be fully encapsulated by grout on all exposed faces.
+
+### Removable shims shall be withdrawn only after the grout has reached sufficient strength to support the plate, and the resulting voids shall be filled with grout.
+
+```datasheet
+label: Leveling method
+type: radio
+options:
+ - Leveling nuts on anchor rods
+ - Steel shims or wedges, removed after cure
+ - Steel shims, left in place and encapsulated
+default: Leveling nuts on anchor rods
+```
+
+# Formwork and Grout Placement {toc}
+
+## Formwork retains the grout and must be sealed so grout fills the space completely without leaking out.
+
+### Grout leaking through gaps between the form and the concrete drains the grout space and leaves voids under the plate; forms are sealed and inspected before placement begins. {note}
+
+### Formwork shall be constructed to retain the grout at the required head and shall be sealed against the concrete and the plate edges to prevent grout loss.
+
+### Form faces in contact with grout shall be coated with a release agent or wax so the forms strip cleanly without bonding to the grout.
+
+### Forms shall be inspected for tightness and proper seal before grout placement begins.
+
+### Forms shall remain in place until the grout has reached at least 75% of its specified strength.
+
+```datasheet
+label: Formwork material
+type: radio
+options:
+ - Wood forms with non-absorptive facing
+ - Rigid foam forms
+ - Steel forms
+default: Wood forms with non-absorptive facing
+```
+
+## Grout is placed from one side to push air ahead of it and fill the space completely.
+
+### Placing grout from a single side, or through fill holes, drives the air across and out the far side; placing from opposing sides simultaneously traps air and leaves voids. {note}
+
+### Grout shall be placed continuously from one side of the plate, or through fill holes, so that grout advances across the space and displaces all air.
+
+### Grout shall be placed continuously and without interruption until grout emerges from all sides and from all grout holes.
+
+### A head of grout shall be maintained on the placement side, or a placement device used, to keep the grout flowing under the plate without forming a cold joint.
+
+### Vibration, rodding, or chaining shall be used only as permitted by the manufacturer and shall not segregate the grout.
+
+### Excess grout that has emerged at the perimeter shall be trimmed and finished to the lines shown after the grout has stiffened.
+
+# Anchor Rod Torquing {toc}
+
+## Anchor rods are torqued after the grout has cured so that torquing does not crack or delaminate the fresh grout bed.
+
+### Torquing anchor rods against a fresh grout bed can crack or delaminate the grout; final torque is applied only after the grout has gained enough strength to resist it. {note}
+
+### Anchor rods shall be torqued only after the grout has reached a minimum of 75% of its specified 28-day compressive strength.
+
+### For cementitious grout, the strength required for torquing is typically reached in 3 to 5 days, and for epoxy grout in about 24 hours at 70°F; the actual time depends on temperature and the manufacturer's strength data. {note}
+
+### Anchor rod torque values shall be as shown on the structural drawings.
+
+### Anchor rods shall be tightened in a uniform, staged sequence so that the plate bears evenly and is not distorted.
+
+### Final torque records shall be made for each base plate confirming the grout strength condition was met before torquing.
+
+```datasheet
+label: Minimum grout strength before anchor rod torquing
+type: range
+unit: "% of specified 28-day strength"
+min: 50
+max: 100
+step: 5
+default: 75
+```
+
+```datasheet
+label: Anchor rod torque value
+type: range
+unit: ft-lb
+min: 0
+max: 1500
+step: 25
+drawing_ref: "anchor rod schedule"
+default: deferred
+```
+
+# Field Verification and Testing {toc}
+
+## Field tests confirm grout consistency, strength, and complete fill before the work is accepted.
+
+### Grout consistency shall be verified at placement against the selected consistency, using the ASTM C939 flow cone where fluid grout is specified.
+
+### Grout compressive strength shall be verified by cube specimens cast during placement and tested per ASTM C109 at the ages required by the Engineer.
+
+### Completeness of fill shall be verified by observing grout emergence at all sides and grout holes during placement and, where required, by sounding the cured grout for voids.
+
+### Hollow-sounding grout, edge cracking, or visible voids shall be reported as nonconformances and evaluated by the Engineer of Record.
+
+### Grout that fails to reach the specified compressive strength, or that exhibits voids or delamination, shall be removed and replaced or repaired as directed by the Engineer of Record.
+
+```datasheet
+label: Grout compressive strength test ages
+type: checkbox
+options:
+ - 1 day
+ - 3 day
+ - 7 day
+ - 28 day
+default:
+ - 7 day
+ - 28 day
+```
+
+```datasheet
+label: Fill verification method
+type: checkbox
+options:
+ - Grout emergence at all sides and holes
+ - Sounding of cured grout for voids
+ - Visual inspection of perimeter
+default:
+ - Grout emergence at all sides and holes
+ - Visual inspection of perimeter
+```
+
+# Delivery, Storage, and Handling {toc}
+
+## Packaged grout is sensitive to moisture and age and must be stored to keep it usable.
+
+### Packaged grout shall be delivered in the manufacturer's original, sealed, labeled containers.
+
+### Grout shall be stored off the ground, under cover, and protected from moisture, in a dry location at the manufacturer's recommended temperature.
+
+### Grout that is caked, partially hydrated, or past the manufacturer's shelf-life date shall not be used.
+
+### Two-component epoxy grout components shall be stored together and within the manufacturer's published temperature range so the components are at placement temperature when mixed.
+
+# Warranty {toc}
+
+## The completed grout installation is warranted against defects in materials and workmanship.
+
+### The Contractor shall warrant the grout installation against voids, cracking, delamination, and failure to reach the specified strength for the period required by the Contract Documents.
+
+### Defective grout discovered within the warranty period shall be removed and replaced at no cost to the Owner.
+
+```datasheet
+label: Warranty period
+type: range
+unit: years
+min: 1
+max: 5
+step: 1
+default: 1
+```