Plan Review: 76 Issues Found

Summary: The Concrete Pier Schedule specifies pier P1 as 24"×24" with 4-#8 vertical bars. The gross area Ag = 24 × 24 = 576 sq in. The total area of longitudinal reinforcement is 4 × 0.79 = 3.16 sq in., yielding a reinforcement ratio of 3.16/576 = 0.0055 (0.55%). ACI 318-14 Section 10.6.1.1 requires the area of longitudinal reinforcement to be at least 0.01Ag = 5.76 sq in. The provided reinforcement of ...

Why it matters: Insufficient longitudinal reinforcement in the pier risks inadequate resistance to bending, creep, and shrinkage effects under sustained compressive loads. Per the ACI 318-14 commentary, the minimum limit exists to prevent reinforcement from yielding under sustained service loads. This deficiency...

Suggested next step: Request the structural engineer review the reinforcement for pier P1 (24"×24" with 4-#8 vertical bars) and confirm compliance with ACI 318-14 Section 10.6.1.1. The minimum longitudinal reinforcement area required is 0.01 × 576 = 5.76 sq in. Either increase the number or size o...

RFI draft: Request the structural engineer review the reinforcement for pier P1 (24"×24" with 4-#8 vertical bars) and confirm compliance with ACI 318-14 Section 10.6.1.1. The minimum longitudinal reinforcement area required is 0.01 × 576 = 5.76 sq in. Either...

Summary: The standard hook detail dimensions the bend for both 90-degree and 180-degree hooks as '4 X BAR DIA - #3 TO #8' and '5 X BAR DIA - #9 TO #11'. ACI 318-14 Table 25.3.1 requires a minimum inside bend diameter of 6db for No. 3 through No. 8 bars and 8db for No. 9 through No. 11 bars for standard hooks used for development of deformed bars in tension. The drawing values of 4db and 5db are signific...

Why it matters: Undersized inside bend diameters risk bar breakage during fabrication and crushing of concrete inside the bend under load. Rebar fabricators and field inspectors referencing this detail could produce or accept non-compliant hooks, leading to structural deficiencies. This discrepancy would likely ...

Suggested next step: Request the structural engineer to revise the standard hook detail to show the correct minimum inside bend diameters per ACI 318-14 Table 25.3.1: 6db for No. 3 through No. 8 bars and 8db for No. 9 through No. 11 bars for both 90-degree and 180-degree standard hooks.

RFI draft: Request the structural engineer to revise the standard hook detail to show the correct minimum inside bend diameters per ACI 318-14 Table 25.3.1: 6db for No. 3 through No. 8 bars and 8db for No. 9 through No. 11 bars for both 90-degree and 180-deg...

Summary: Detail 8 (SECTION- UTILITY PIPE THRU WALL FOOTING) shows the bottom foundation reinforcement ('MATCH FTG REINF') continuously bending to follow the exterior corners at the lowest elevation of the stepped wall footing. When the wall footing acts in flexure and this bottom reinforcement is subjected to tension, bending a continuous tension bar around these corners creates an unresisted outward re...

Why it matters: Failure to properly anchor this tension reinforcement will lead to localized concrete spalling, uncontrolled cracking, and a severe loss of structural integrity at the step. This compromises the foundation's ability to resist bending moments and transfer loads across the utility pipe crossing, po...

Suggested next step: Please revise Detail 8 to show the top and bottom footing reinforcement properly detailed at the steps (e.g., crossing the bars and extending them straight into the concrete mass for proper development, rather than continuously bending them around the corners), to prevent conc...

RFI draft: Please revise Detail 8 to show the top and bottom footing reinforcement properly detailed at the steps (e.g., crossing the bars and extending them straight into the concrete mass for proper development, rather than continuously bending them around...

Summary: The bracing connection detail instructs to "WELD TO DEVELOP SUM OF HORIZONTAL COMPONENTS OF BRACING FORCES" for the gusset-to-beam connection at a "CHEVRON BRACE". Chevron bracing inherently exerts both horizontal and vertical force components onto the beam. By explicitly limiting the weld design to only the sum of the horizontal components, the detail fails to provide capacity for the vertical...

Why it matters: If the gusset-to-beam weld is designed and installed solely for horizontal forces, it will lack the structural capacity to transfer the required vertical forces from the braces. This creates a severe risk of connection failure under seismic or high wind loading, which could compromise the lateral...

Suggested next step: Please revise the welding instructions for the chevron brace connection to require the gusset-to-beam weld to develop all applicable brace force components (both horizontal and vertical), including unbalanced forces as required by the applicable seismic design provisions.

RFI draft: Please revise the welding instructions for the chevron brace connection to require the gusset-to-beam weld to develop all applicable brace force components (both horizontal and vertical), including unbalanced forces as required by the applicable s...

Summary: Detail 3/S403 specifies "(4) 3/4\" Ø A325 THREADED STUDS WELDED ALL AROUND TO PL" for the canopy connection. ASTM A325 (now ASTM F3125 Grade A325) designates high-strength, quenched and tempered fasteners. Welding to quenched and tempered steel alters its heat treatment and severely degrades its mechanical strength. This practice is strictly prohibited under standard structural steel fabricatio...

Why it matters: IBC Section 2205.1 requires structural steel design, fabrication, and erection to comply with AISC 360. Allowing A325 high-strength fasteners to be welded violates this requirement and creates a critical life-safety hazard. The compromised studs could fail in a brittle, unpredictable manner under...

Suggested next step: Request the Engineer of Record to revise the canopy connection detail. Recommend replacing the A325 threaded studs with a weldable steel grade (e.g., ASTM A108 Nelson studs) or redesigning the connection to utilize standard through-bolting with nuts to completely avoid welding...

RFI draft: Request the Engineer of Record to revise the canopy connection detail. Recommend replacing the A325 threaded studs with a weldable steel grade (e.g., ASTM A108 Nelson studs) or redesigning the connection to utilize standard through-bolting with nu...

Summary: Plan sheet S101 explicitly calls out the elevator pit as an '8" REINF & GROUTED CMU ELEVATOR PIT'. In direct contradiction, the referenced elevator pit section detail (5/S301) shows the pit wall below the slab as a '10"' thick cast-in-place concrete wall with a continuous waterstop ('PROVIDE CONT SELF EXPANDING STRIP WATERSTOP').

Why it matters: Cast-in-place concrete with waterstops performs fundamentally differently for structural loads and groundwater control compared to grouted CMU. This discrepancy impacts formwork, waterproofing approaches, structural integrity, and project scheduling.

Suggested next step: Please clarify if the elevator pit walls below the slab-on-grade should be constructed of 8" reinforced CMU as noted on the plan, or 10" cast-in-place concrete with waterstops as detailed in section 5/S301.

RFI draft: Please clarify if the elevator pit walls below the slab-on-grade should be constructed of 8" reinforced CMU as noted on the plan, or 10" cast-in-place concrete with waterstops as detailed in section 5/S301.

Summary: Framing plans designate the beam along Grid 4 as part of a braced frame (indicated by the "(BF)" note alongside beam W18X40, with reference to braced frame elevation 6/S201). However, the Column Schedule on S501 fails to designate the columns located on this grid (C-4 and B-4) with the "(BF)" note.

Why it matters: The "COLUMN SCHEDULE LEGEND" specifies that "(BF)" denotes a column that is part of a braced frame and requires additional detailing per S201. Omitting this designation on the schedule for columns structurally part of a braced frame could lead to the fabricator missing required gusset plates, sti...

Suggested next step: Please clarify if the columns located along Grid 4 (C-4 and B-4) should be designated as (BF) in the Column Schedule to match the braced frames indicated on the framing plans.

RFI draft: Please clarify if the columns located along Grid 4 (C-4 and B-4) should be designated as (BF) in the Column Schedule to match the braced frames indicated on the framing plans.

Summary: Detail 3/S403 specifies 3/4" Ø A325 threaded studs to be "WELDED ALL AROUND TO PL". ASTM A325 fasteners are heat-treated, high-strength components. The General Notes require all structural steel detailing, fabrication, and erection to comply with AISC 360. As a referenced standard, AISC 360 explicitly prohibits the welding of A325 bolts because the high heat of welding destroys their heat treat...

Why it matters: If these high-strength studs are welded as detailed, their strength and ductility will be unpredictable and severely degraded, posing a significant risk of connection failure at the canopy. This will likely fail special inspection and require a field fix or redesign.

Suggested next step: Please advise if the threaded studs should be specified as a weldable grade material (e.g., ASTM F1554 Gr. 36 or ASTM A108) or if the connection should be redesigned to avoid welding the high-strength studs directly to the plate.

RFI draft: Please advise if the threaded studs should be specified as a weldable grade material (e.g., ASTM F1554 Gr. 36 or ASTM A108) or if the connection should be redesigned to avoid welding the high-strength studs directly to the plate.

Summary: In Detail 4/S202, the note for the gusset plate to beam weld instructs to 'WELD TO DEVELOP SUM OF HORIZONTAL COMPONENTS OF BRACING FORCES'. This is a clear mistake according to standard engineering practice. Chevron braces impart both horizontal shear and vertical forces (which cause bending/moment on the gusset plate) to the beam. Sizing the weld solely for the horizontal components ignores th...

Why it matters: If the connection is designed only for the horizontal forces, the weld will be under-sized for the actual combined shear and tension/compression loads caused by the vertical components of the braces, potentially leading to a catastrophic connection failure under lateral loading (e.g., wind or sei...

Suggested next step: Please confirm that the gusset-to-beam weld must be designed by the delegated engineer for the combined horizontal and vertical bracing forces (including unbalanced forces), and clarify or revise the note limiting the design to the 'SUM OF HORIZONTAL COMPONENTS'.

RFI draft: Please confirm that the gusset-to-beam weld must be designed by the delegated engineer for the combined horizontal and vertical bracing forces (including unbalanced forces), and clarify or revise the note limiting the design to the 'SUM OF HORIZON...

Summary: Detail 2/S301 notes that the vapor retarder is to extend "ATOP PIER". Placing a vapor retarder (a polyethylene slip sheet) on top of the structural concrete pier, directly beneath the column base plate and non-shrink grout, is an incorrect detail according to standard practice. It breaks the bond and friction transfer between the column base and the pier.

Why it matters: Installing a slip plane under a structural column base compromises the column's ability to transfer lateral shear forces via friction to the concrete foundation. This endangers the structural integrity of the work.

Suggested next step: Detail 2/S301 directs the vapor retarder to extend 'ATOP PIER', which would place it under the column base plate and non-shrink grout, compromising shear friction transfer. Please confirm if the vapor retarder should instead terminate at the sides of the pier or be cut around ...

RFI draft: Detail 2/S301 directs the vapor retarder to extend 'ATOP PIER', which would place it under the column base plate and non-shrink grout, compromising shear friction transfer. Please confirm if the vapor retarder should instead terminate at the sides...

Summary: Plan Note 17 specifies elevator shaft wall reinforcement with '#4 @ 4'-0" VERT', which is a 48-inch vertical bar spacing. ACI 318-14 Section 11.7.2.1 requires that spacing of longitudinal bars in cast-in-place walls shall not exceed the lesser of 3h and 18 inches. For any wall thickness up to and including 16 inches, the 18-inch limit controls, resulting in a maximum permitted spacing of 18 inc...

Why it matters: Excessive vertical reinforcement spacing in elevator shaft walls could result in inadequate crack control and reduced structural capacity, particularly under lateral loads. Elevator shaft walls are critical structural elements that typically resist both gravity and lateral forces. Correction woul...

Suggested next step: Clarify whether the elevator shaft walls referenced in Plan Note 17 are cast-in-place concrete or masonry (CMU). If cast-in-place concrete, revise the vertical reinforcement spacing from #4 @ 4'-0" OC to a maximum of 18 inches on center to comply with ACI 318-14 Section 11.7.2...

RFI draft: Clarify whether the elevator shaft walls referenced in Plan Note 17 are cast-in-place concrete or masonry (CMU). If cast-in-place concrete, revise the vertical reinforcement spacing from #4 @ 4'-0" OC to a maximum of 18 inches on center to comply ...

Summary: Plan Notes 3 and 3A specify Welded Wire Reinforcement using plain wires (WWR 6X6XW2.1XW2.1) for the concrete floor composition. However, ACI 318-14 Section 20.2.1.1 mandates that all nonprestressed wires must be deformed, with an exception only for plain wires used in spirals. Because the floor slab deck is not a spiral, the use of plain wire (W2.1) violates this code requirement.

Why it matters: Using plain wire instead of deformed wire in a floor slab reduces the mechanical bond and anchorage between the concrete and the reinforcement. This can compromise the structural capacity, shrinkage crack control, and overall integrity of the floor system, leading to rejection during structural r...

Suggested next step: Please revise Plan Notes 3 and 3A to specify deformed Welded Wire Reinforcement (e.g., WWR 6x6xD2.1xD2.1) to comply with the deformed wire requirements of ACI 318-14 Section 20.2.1.1, or clarify if an alternate approved code section applies to this application.

RFI draft: Please revise Plan Notes 3 and 3A to specify deformed Welded Wire Reinforcement (e.g., WWR 6x6xD2.1xD2.1) to comply with the deformed wire requirements of ACI 318-14 Section 20.2.1.1, or clarify if an alternate approved code section applies to thi...

Summary: The RETAINING WALL DIMENSION & REINFORCEMENT SCHEDULE specifies a stem thickness (S) of 1'-0" (12") for the '4' TO 8'' and 'UP TO 4'' wall heights, with HORZ STEM D-BARS called out as #4@12". This provides 0.20 in²/ft of horizontal reinforcement, yielding a transverse reinforcement ratio ρt of 0.00139 (0.20 / 144 in²). For the '8' TO 12'' wall height, the stem thickness is 1'-2" (14") with HORZ...

Why it matters: Failing to provide the minimum required transverse (horizontal) reinforcement violates the building code's shrinkage and temperature crack control provisions. In retaining walls, inadequate transverse reinforcement leads to excessive cracking, permitting water intrusion, accelerating corrosion of...

Suggested next step: Please revise the 'HORZ STEM D-BARS' in the Retaining Wall Dimension & Reinforcement Schedule to satisfy the minimum transverse reinforcement ratio ρt of 0.0020 as required by ACI 318-14 Section 11.1.4 and Table 11.6.1.

RFI draft: Please revise the 'HORZ STEM D-BARS' in the Retaining Wall Dimension & Reinforcement Schedule to satisfy the minimum transverse reinforcement ratio ρt of 0.0020 as required by ACI 318-14 Section 11.1.4 and Table 11.6.1.

Summary: Detail 2/S401 specifies a "#4@12"x4'-0" W/ STD 90 DEG HOOK WHERE 'X' DIMENSION IS GREATER THAN 4"" for the slab edge reinforcement. Per ACI 318 Table 25.3.1, a standard 90-degree hook for a No. 4 bar (db = 0.5 inches) requires a straight extension of 12db (6 inches) and a minimum inside bend diameter of 6db (3 inches). The total vertical depth of the hook is therefore 8 inches. However, Detail ...

Why it matters: During construction, the ironworkers will be unable to install the detailed #4 standard 90-degree hook, as the 6-inch straight extension will protrude through the bottom of the deck or formwork. This geometric impossibility will result in an RFI and placement delay. A different detail must be pro...

Suggested next step: The required overall depth for a standard 90-degree hook on a No. 4 bar is 8 inches (6-inch straight extension plus 2-inch bend radius and bar diameter), which will not fit within the total thickness of the slab on deck edge. Please advise if a 180-degree hook can be used inst...

RFI draft: The required overall depth for a standard 90-degree hook on a No. 4 bar is 8 inches (6-inch straight extension plus 2-inch bend radius and bar diameter), which will not fit within the total thickness of the slab on deck edge. Please advise if a 18...

Summary: The 'TYPE A' base plate detail illustrates six anchor rod holes arranged with a vertical center-to-center spacing of 2" between adjacent holes. However, the project's Base Plate Schedule specifies a minimum anchor rod diameter of 3/4" (AR1 3/4"Ø). ACI 318-14 Section 17.7.1 requires a minimum center-to-center spacing for anchors of 4da, which equates to a minimum spacing of 3" for the 3/4" ancho...

Why it matters: Installing anchors with a center-to-center spacing less than 4da can lead to overlapping concrete breakout cones, significantly reducing the tensile capacity of the anchorage group. This increases the risk of concrete splitting failure during anchor torquing or under service loads, compromising t...

Suggested next step: Please revise the TYPE A base plate detail to increase the vertical spacing between anchor rod holes to a minimum of 4da (at least 3" for 3/4" anchors, or larger if utilized with larger anchors) to comply with ACI 318-14 Section 17.7.1.

RFI draft: Please revise the TYPE A base plate detail to increase the vertical spacing between anchor rod holes to a minimum of 4da (at least 3" for 3/4" anchors, or larger if utilized with larger anchors) to comply with ACI 318-14 Section 17.7.1.