---
title: Concrete Equipment Pads
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When to use: Cast-in-place concrete pads on grade or on slab that support mechanical and electrical equipment located outside the building envelope or in service yards. Typical applications include generator pads, pad-mounted transformer pads, switchgear and section-switch pads, condensing-unit and rooftop unit (RTU) pads where set at grade or on an exterior platform, pump and chiller pads, and similar isolated equipment foundations. Covers subgrade preparation references, formwork, mix selection, reinforcement, embedded anchor bolts, embedded grounding and conduit stubs, pour and consolidation, curing, finishing, tolerances, isolation joints to adjacent flatwork, and inspection.
− Not intended for: Structural foundations integral to the building (footings, grade beams, mat foundations, pile caps) — see [[syncs/cast-in-place-concrete]]. Interior housekeeping pads inside mechanical and electrical rooms placed as a thin topping on the building slab — use [[syncs/cast-in-place-concrete]] for the topping pour. Precast concrete vault pads or precast transformer pads supplied with the equipment. Concrete-encased duct banks. Site flatwork (sidewalks, exterior slabs-on-grade) intended for pedestrian or vehicle traffic. Aggregate base course beneath the pad — see [[syncs/aggregate-base-course]]. Mass earthwork and subgrade preparation below the base course — see [[syncs/earthwork]].
+ Not intended for: Structural foundations integral to the building (footings, grade beams, mat foundations, pile caps) — see [[sync/cast-in-place-concrete]]. Interior housekeeping pads inside mechanical and electrical rooms placed as a thin topping on the building slab — use [[sync/cast-in-place-concrete]] for the topping pour. Precast concrete vault pads or precast transformer pads supplied with the equipment. Concrete-encased duct banks. Site flatwork (sidewalks, exterior slabs-on-grade) intended for pedestrian or vehicle traffic. Aggregate base course beneath the pad — see [[sync/aggregate-base-course]]. Mass earthwork and subgrade preparation below the base course — see [[sync/earthwork]].
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## Inherited and Supplemental Requirements {toc}
−### This standard inherits the general requirements of [[syncs/cast-in-place-concrete]] for concrete materials, mix design, placement, and quality control. {note}
−### It inherits the requirements of [[syncs/concrete-reinforcement]] for reinforcing steel materials, fabrication, placement tolerances, and cover. {note}
−### It inherits the requirements of [[syncs/aggregate-base-course]] for the base course on which the pad bears and the requirements of [[syncs/earthwork]] for subgrade preparation. {note}
+### This standard inherits the general requirements of [[sync/cast-in-place-concrete]] for concrete materials, mix design, placement, and quality control. {note}
+### It inherits the requirements of [[sync/concrete-reinforcement]] for reinforcing steel materials, fabrication, placement tolerances, and cover. {note}
+### It inherits the requirements of [[sync/aggregate-base-course]] for the base course on which the pad bears and the requirements of [[sync/earthwork]] for subgrade preparation. {note}
### Requirements specific to equipment pads — anchorage, embedded grounding, coordination with equipment manufacturer dimensions, finish, and isolation from adjacent flatwork — supplement and do not replace the parent standards.
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### No pad shall be placed until the corresponding submittals have been reviewed and returned.
−- Concrete mix design for the pad concrete class, prepared in accordance with [[syncs/cast-in-place-concrete]], showing cementitious materials, aggregates, admixtures, water content, target water-to-cementitious materials ratio, and the trial batch or field-record documentation establishing the required average strength
−- Reinforcing steel shop drawings and bar lists conforming to [[syncs/concrete-reinforcement]], showing bar sizes, grades, lengths, bends, spacing, and concrete cover for each pad type
+- Concrete mix design for the pad concrete class, prepared in accordance with [[sync/cast-in-place-concrete]], showing cementitious materials, aggregates, admixtures, water content, target water-to-cementitious materials ratio, and the trial batch or field-record documentation establishing the required average strength
+- Reinforcing steel shop drawings and bar lists conforming to [[sync/concrete-reinforcement]], showing bar sizes, grades, lengths, bends, spacing, and concrete cover for each pad type
- Anchor bolt setting drawings, prepared from the equipment manufacturer's certified anchorage pattern for the specific equipment being supported, showing anchor bolt grade, diameter, embedment length, projection above pad, bolt circle or rectangular pattern dimensions, sleeve or template details, and the orientation of the pattern relative to the building grid or compass direction
- Formwork shop drawings or product data for proprietary pad forming systems, including provision for chamfer at exposed edges
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## Testing Agency {toc}
−### Concrete testing for equipment pads shall be performed by the project's concrete testing agency qualified per [[syncs/cast-in-place-concrete]].
−### Compressive strength cylinders shall be cast from each pad placement in accordance with [[syncs/cast-in-place-concrete]].
+### Concrete testing for equipment pads shall be performed by the project's concrete testing agency qualified per [[sync/cast-in-place-concrete]].
+### Compressive strength cylinders shall be cast from each pad placement in accordance with [[sync/cast-in-place-concrete]].
### A single small pad does not require a full set of cylinders if it is placed from the same truck as a larger element that is tested, but each truck delivered shall be sampled at least once per ACI SPEC-301.
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```
−### The subgrade beneath an equipment pad on grade shall be prepared in accordance with [[syncs/earthwork]] and shall receive an aggregate base course in accordance with [[syncs/aggregate-base-course]].
+### The subgrade beneath an equipment pad on grade shall be prepared in accordance with [[sync/earthwork]] and shall receive an aggregate base course in accordance with [[sync/aggregate-base-course]].
### The Contractor shall not place a pad directly on natural undisturbed soil unless the geotechnical report specifically authorizes it for the soil type encountered and the equipment loading anticipated.
### The aggregate base course beneath the pad shall be at least as thick as the base course shown on the contract drawings, but in no case less than 4 in. for light equipment (condensing units, small pumps) and 6 in. for heavier equipment (generators, transformers).
−### The base shall be compacted to the density required by [[syncs/aggregate-base-course]] and shall be proof rolled before the pad is formed.
+### The base shall be compacted to the density required by [[sync/aggregate-base-course]] and shall be proof rolled before the pad is formed.
## Base Course Moisture {toc}
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# Concrete Mix {toc}
−## The concrete mix shall conform to [[syncs/cast-in-place-concrete]] and to the additional requirements below.
+## The concrete mix shall conform to [[sync/cast-in-place-concrete]] and to the additional requirements below.
## The pad concrete is typically a single class used throughout all pads on the project; where pad applications differ significantly (e.g., a light condensing-unit pad and a heavy generator pad), separate mix classes may be specified.
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# Reinforcement {toc}
−## Reinforcement shall be furnished, fabricated, and placed in accordance with [[syncs/concrete-reinforcement]].
+## Reinforcement shall be furnished, fabricated, and placed in accordance with [[sync/concrete-reinforcement]].
## The default reinforcement for an equipment pad is a top and bottom mat of deformed bars in each direction, sized and spaced as shown on the contract drawings. {note}
## Where the contract drawings do not specify reinforcement, the default below shall apply.
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## Reinforcement Support and Placement {toc}
−### Reinforcement shall be supported on plastic-tipped wire chairs, all-plastic chairs, or precast concrete block chairs in accordance with [[syncs/concrete-reinforcement]].
+### Reinforcement shall be supported on plastic-tipped wire chairs, all-plastic chairs, or precast concrete block chairs in accordance with [[sync/concrete-reinforcement]].
### Bare wire chairs shall not be used in exterior or F1/F2 exposure pads because they corrode and stain the pad surface.
### Bars shall be tied at intersections sufficiently to maintain position during anchor bolt installation and concrete consolidation.
### The reinforcing mat shall be positioned to avoid conflict with anchor bolts and conduit stubs.
−### Where an anchor bolt or conduit conflicts with a planned bar position, the bar shall be cut and replaced with two bars splayed around the embed, splice length per [[syncs/concrete-reinforcement]]; bars shall not simply be omitted at conflicts.
+### Where an anchor bolt or conduit conflicts with a planned bar position, the bar shall be cut and replaced with two bars splayed around the embed, splice length per [[sync/concrete-reinforcement]]; bars shall not simply be omitted at conflicts.
# Anchor Bolts {toc}
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### Conduit stubs serving the equipment shall enter the pad from below per the contract drawings and shall be terminated above the finished pad surface as required by the equipment manufacturer for that conduit connection.
−### Conduit type and material shall conform to [[syncs/raceways-and-conduit]].
+### Conduit type and material shall conform to [[sync/raceways-and-conduit]].
### Conduit shall be capped during concrete placement to prevent debris from entering and shall be supported to resist displacement during pour.
### Where conduits are clustered (e.g., multiple feeders entering a generator or a transformer secondary), the cluster spacing shall match the manufacturer's cable trough opening; conduits shall not foul the equipment base.
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−### Grounding shall be provided in accordance with [[syncs/grounding-and-bonding]] and, for substation-class transformer installations, in accordance with IEEE 80.
−### For pad-mounted transformers, the grounding electrode conductor shall stub through the pad at the location designated on the manufacturer's anchorage and grounding drawing and shall be left of sufficient length to terminate inside the transformer tank or at the equipment ground bus per [[syncs/grounding-and-bonding]].
+### Grounding shall be provided in accordance with [[sync/grounding-and-bonding]] and, for substation-class transformer installations, in accordance with IEEE 80.
+### For pad-mounted transformers, the grounding electrode conductor shall stub through the pad at the location designated on the manufacturer's anchorage and grounding drawing and shall be left of sufficient length to terminate inside the transformer tank or at the equipment ground bus per [[sync/grounding-and-bonding]].
### Coiling excess conductor inside the pad cavity is acceptable provided the coil does not interfere with cable termination.
### For generator pads, the grounding electrode conductor connection shall be coordinated with the generator manufacturer's grounding lug location, with the building grounding electrode system, and with the separately derived system grounding requirements of NFPA 70 Article 250.
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### Free-fall distance shall not exceed 4 ft.
### Buggy or wheelbarrow placement is acceptable for small pads not accessible by truck or pump.
−### Placement shall conform to [[syncs/cast-in-place-concrete]].
+### Placement shall conform to [[sync/cast-in-place-concrete]].
## Anchor Bolt and Embed Verification Immediately Before Pour {toc}
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# Curing and Protection {toc}
−## Curing shall conform to [[syncs/cast-in-place-concrete]] and ACI 308R.
+## Curing shall conform to [[sync/cast-in-place-concrete]] and ACI 308R.
## Curing Method and Duration {toc}
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options:
- "Not required — ambient < 90°F, moderate humidity"
− - "Required — per ACI 305R and [[syncs/cast-in-place-concrete]]"
+ - "Required — per ACI 305R and [[sync/cast-in-place-concrete]]"
default: "Not required — ambient < 90°F, moderate humidity"
```
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options:
- "Not required — ambient > 40°F through protection period"
− - "Required — per ACI 306R and [[syncs/cast-in-place-concrete]]"
+ - "Required — per ACI 306R and [[sync/cast-in-place-concrete]]"
default: "Not required — ambient > 40°F through protection period"
```
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### Where an equipment pad is placed adjacent to a sidewalk, driveway, exterior slab, or building floor slab, an isolation joint shall be provided between the pad and the adjacent flatwork.
−### Isolation joints shall be full-depth pre-molded joint filler in accordance with [[syncs/cast-in-place-concrete]].
+### Isolation joints shall be full-depth pre-molded joint filler in accordance with [[sync/cast-in-place-concrete]].
### The joint shall be sealed at the surface with an elastomeric joint sealant where the joint is exposed to traffic, water, or where its open condition would be unsightly.
### The sealant shall be compatible with the joint filler and shall be installed in accordance with the sealant manufacturer's instructions.
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## Field Testing of Concrete {toc}
−### Field testing of fresh concrete (slump, air content, temperature) and casting of compressive strength cylinders shall be performed in accordance with [[syncs/cast-in-place-concrete]].
+### Field testing of fresh concrete (slump, air content, temperature) and casting of compressive strength cylinders shall be performed in accordance with [[sync/cast-in-place-concrete]].
### For project sites with multiple pads placed from a common pour, a single set of acceptance cylinders may serve multiple pads provided the placements occur on the same day from the same delivered concrete.
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## Storage and Handling {toc}
−### Reinforcing steel shall be delivered, stored, and handled in accordance with [[syncs/concrete-reinforcement]].
+### Reinforcing steel shall be delivered, stored, and handled in accordance with [[sync/concrete-reinforcement]].
### Anchor bolts shall be delivered to the site in clearly identified bundles or boxes with manufacturer's certification (mill test reports for the bolt steel and zinc coating thickness verification for galvanized bolts) and shall be stored on supports above grade in a manner that prevents thread damage and contamination.
### Thread protectors shall remain in place from delivery through installation.
−### Concrete shall be delivered in accordance with ASTM C94 and [[syncs/cast-in-place-concrete]].
+### Concrete shall be delivered in accordance with ASTM C94 and [[sync/cast-in-place-concrete]].
### Curing compounds, form release, and curing blankets shall be stored in accordance with the manufacturer's recommendations, protected from freezing and from exposure to sunlight where the product is light-sensitive.
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### The Contractor shall not perform structural repairs (epoxy injection, replacement, anchor relocation) without written direction from the Engineer of Record.
−### Cosmetic repairs to non-structural surface defects may proceed in accordance with [[syncs/cast-in-place-concrete]].
+### Cosmetic repairs to non-structural surface defects may proceed in accordance with [[sync/cast-in-place-concrete]].
# Warranty {toc}
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### The warranty shall not apply to damage caused by equipment loads exceeding the design basis, to damage from vehicle impact or other external causes, or to settlement caused by subgrade conditions outside the Contractor's scope.
### Material warranties for proprietary anchor systems, post-installed anchors, repair mortars, and joint sealants used in the pad work shall be passed through to the Owner and included in the closeout submittals.
−### Coordinate equipment-labeling and pad-mounted equipment identification with [[syncs/equipment-labeling]] and the supporting equipment specifications [[syncs/generators]] and [[syncs/transformers]].
+### Coordinate equipment-labeling and pad-mounted equipment identification with [[sync/equipment-labeling]] and the supporting equipment specifications [[sync/generators]] and [[sync/transformers]].