Plan Review: 203 Issues Found

Summary: Detail 4 'STEEL COLUMN AT PT SLAB' specifies a base plate with (4) 3/4" diameter anchors. The plan view dimensions explicitly show a horizontal center-to-center spacing of 2-1/2" between anchors. Per ACI 318-14 Section 17.7.1, the minimum center-to-center spacing of anchors shall be 4da. For 3/4" diameter anchors, the minimum required spacing is 4 × 0.75" = 3.0". The drawing shows 2-1/2" (2.5")...

Why it matters: Insufficient anchor spacing can lead to concrete splitting failure during installation or under load, compromising the capacity of the HSS column base connection. This could result in a failed inspection and would require redesign of the base plate and anchor layout, potentially increasing the pl...

Suggested next step: Request the structural engineer of record to revise the base plate anchor layout in Detail 4 to provide a minimum center-to-center anchor spacing of 3.0" (4da for 3/4" dia anchors) in accordance with ACI 318-14 Section 17.7.1. Confirm whether the base plate dimensions need to ...

RFI draft: Request the structural engineer of record to revise the base plate anchor layout in Detail 4 to provide a minimum center-to-center anchor spacing of 3.0" (4da for 3/4" dia anchors) in accordance with ACI 318-14 Section 17.7.1. Confirm whether the ...

Summary: The structural plan specifies a "12" P-T SLAB" with a "FLAT SOFFIT AT COURTYARD". However, the post-tensioning tendon profile labels specify Center of Gravity of Steel (CGS) heights of "13"" and "19 1/2"". Note 18 explicitly states that this dimension indicates the distance "FROM BOTTOM OF SLAB TO CENTROID OF POST-TENSIONED STRANDS". Because the specified CGS heights (13" and 19.5") exceed the ...

Why it matters: Specifying a tendon profile that is taller than the concrete slab makes it physically impossible to build while maintaining any concrete cover, violating fire and durability requirements. If formwork is erected for a 12-inch slab, the tendon support chairs at these high points will protrude above...

Suggested next step: Please review the specified PT tendon CGS profile heights of 13" and 19 1/2" located within the 12" P-T SLAB area. These specified heights exceed the 12" slab thickness, placing the tendons outside the concrete. Clarify if the slab thickness should be increased, if drop panels...

RFI draft: Please review the specified PT tendon CGS profile heights of 13" and 19 1/2" located within the 12" P-T SLAB area. These specified heights exceed the 12" slab thickness, placing the tendons outside the concrete. Clarify if the slab thickness shoul...

Summary: Foundation Plan Note 12 explicitly states the foundation design uses an allowable bearing pressure of 5,000 PSF "WITH A 1/3 INCREASE FOR WIND/SEISMIC FORCES." ASCE 7-16 Section 2.4.1 prohibits increases in allowable stress for the load combinations given in the standard, stating: "Increases in allowable stress shall not be used with the loads or load combinations given in this standard unless i...

Why it matters: Using the prohibited 1/3 stress increase results in foundation elements designed for a higher effective allowable bearing pressure (6,667 PSF instead of 5,000 PSF) under wind/seismic combinations. This means footings may be undersized for lateral load combinations, potentially leading to bearing ...

Suggested next step: Please confirm the foundation design methodology and load combinations used. ASCE 7-16 Section 2.4.1 prohibits increases in allowable stress for load combinations in the standard. Please revise Foundation Plan Note 12 to remove the 1/3 allowable bearing pressure increase for w...

RFI draft: Please confirm the foundation design methodology and load combinations used. ASCE 7-16 Section 2.4.1 prohibits increases in allowable stress for load combinations in the standard. Please revise Foundation Plan Note 12 to remove the 1/3 allowable b...

Summary: Detail 13 (ROOF DAVIT) on sheet S5.65 specifies the truss design load as 'DESIGN TRUSS FOR 3K FALL ARREST LOAD (ASD)', which equals 3,000 lb. ASCE 7-16 Section 4.6.5 requires that fall arrest anchorages and the structural elements supporting them be designed for a live load of 3,100 lb (13.8 kN) for each attached lifeline. The specified 3,000 lb design load is 100 lb less than the code-mandated...

Why it matters: This is a life-safety issue involving fall protection for building maintenance personnel. A plan reviewer will likely flag this discrepancy, causing a plan check correction and resubmittal delay. The truss manufacturer design, blocking, and connection hardware (6x8 blocking, Simpson HU66 hangers,...

Suggested next step: Request that the structural engineer revise Detail 13 (ROOF DAVIT) to specify a fall arrest design load of not less than 3,100 lb per ASCE 7-16 Section 4.6.5, and confirm that all supporting structural elements (truss, blocking, connections, and anchorage hardware) have adequa...

RFI draft: Request that the structural engineer revise Detail 13 (ROOF DAVIT) to specify a fall arrest design load of not less than 3,100 lb per ASCE 7-16 Section 4.6.5, and confirm that all supporting structural elements (truss, blocking, connections, and a...

Summary: Plan Note 9 states that drag forces are provided at allowable stress levels ("0.6W" and "0.7E") but instructs the truss manufacturer to use them "in conjunction with ASCE 7-16 load combinations". The ASCE 7-16 load combinations in Section 2.4.1 and Section 2.4.5 apply the 0.6 and 0.7 reduction factors to nominal (ultimate) wind and seismic loads. Inputting pre-factored allowable values into the...

Why it matters: If the truss manufacturer inputs these values directly into standard ASCE 7-16 load combinations, the truss elements and connections acting as collectors/drag struts will be designed for roughly 36% of the required wind force and 49% of the required seismic force. This compromises the continuous ...

Suggested next step: Clarify if the drag forces provided on the plan are nominal (ultimate) W and E values to be used in ASCE 7-16 load combinations, or if they are already at ASD levels. If they are already at ASD levels, please instruct the truss manufacturer to apply a 1.0 multiplier to these l...

RFI draft: Clarify if the drag forces provided on the plan are nominal (ultimate) W and E values to be used in ASCE 7-16 load combinations, or if they are already at ASD levels. If they are already at ASD levels, please instruct the truss manufacturer to app...

Summary: The foundation plan designates large areas as "FUTURE SLAB EXTENTS" where the slab-on-grade will not be constructed initially. Within and adjacent to these hatched areas, isolated column spread footings (e.g., at TOF=98'-0") are detailed without any interconnecting grade beams, tie beams, or drag struts. Because the concrete shearwalls are identified as the Seismic Force Resiting System (SFRS),...

Why it matters: ASCE 7-16 Section 12.1.3 requires that all parts of the structure be interconnected to form a continuous load path to the seismic force-resisting system. Without the slab on grade or alternative foundation-level ties, base shear from the isolated columns cannot be safely transferred to the SFRS. ...

Suggested next step: Clarify how base shear and lateral column base restraint are achieved in the "FUTURE SLAB EXTENTS" areas prior to the slab being poured. Provide foundation-level tie beams, drag struts, or temporary lateral bracing for all isolated columns in these zones to establish a continu...

RFI draft: Clarify how base shear and lateral column base restraint are achieved in the "FUTURE SLAB EXTENTS" areas prior to the slab being poured. Provide foundation-level tie beams, drag struts, or temporary lateral bracing for all isolated columns in thes...

Summary: Detail 2 ('SLIP CONNECTION AT FLOOR') specifies attaching the slip track to the ceiling/floor above, which is labeled as a 'PT SLAB', using '(3) SHOT PINS AT EACH STUD'. Specifying powder-actuated fasteners (shot pins) for attachment into a post-tensioned (PT) concrete slab is a critical mistake. These fasteners can easily penetrate the concrete and sever the embedded high-strength post-tension...

Why it matters: Severing a PT tendon is extremely dangerous. It releases immense stored energy, which can cause explosive concrete spalling and tendon ejection, leading to severe injury or death to workers. It also significantly compromises the structural capacity of the slab, requiring highly expensive and time...

Suggested next step: Please revise Detail 2 to strictly prohibit the use of powder-actuated fasteners (shot pins) into the PT slab. Specify shallow drilled concrete anchors and require the contractor to scan the slab using GPR to locate and avoid all PT tendons prior to any drilling.

RFI draft: Please revise Detail 2 to strictly prohibit the use of powder-actuated fasteners (shot pins) into the PT slab. Specify shallow drilled concrete anchors and require the contractor to scan the slab using GPR to locate and avoid all PT tendons prior ...

Summary: Detail 6 illustrates a "16\" MAX" gap in the "TOP PLATE AT STRUCTURAL WALL" to accommodate a "PIPE GROUP". The detail specifies bridging this gap using only a flat metal "STRAP". While a flat steel strap can transfer tension forces across the gap, it has virtually no buckling capacity and cannot resist compression forces over a 16-inch unsupported span. Top plates in structural walls act as cho...

Why it matters: This explicitly violates ASCE 7 Section 12.1.3, which mandates a continuous load path with adequate strength and stiffness to transfer all forces. A compression failure of the chord/collector at this gap could lead to excessive diaphragm deflection, tearing of the lateral system, and localized wa...

Suggested next step: Please provide a revised detail showing how compressive forces in the structural wall top plate are to be transferred across the 16" maximum pipe gap (e.g., adding continuous compression blocking around the pipes or integrating a structural steel channel).

RFI draft: Please provide a revised detail showing how compressive forces in the structural wall top plate are to be transferred across the 16" maximum pipe gap (e.g., adding continuous compression blocking around the pipes or integrating a structural steel ...

Summary: Details 17, 18, and 19 show exterior balcony joists and dropped corridor framing supported by a 2x ledger that is face-fastened to the rim joist using SDS screws. Out-of-plane lateral seismic forces pulling the balcony or corridor away from the main floor will transfer tension through the ledger and screws directly into the face of the rim joist. Because the rim joist is only supported at its t...

Why it matters: Relying on the cross-grain tension capacity of a rim joist to resist lateral separation forces is a severe structural deficiency and a primary cause of catastrophic deck and balcony collapses. A dedicated lateral tension tie system is required to transfer lateral forces through the rim joist dire...

Suggested next step: Please revise Details 17, 18, and 19 to provide positive lateral tension ties (e.g., Simpson DTT1Z or DTT2Z hold-downs) spaced appropriately to connect the exterior balcony and dropped corridor joists directly to the interior floor framing. This ensures a continuous load path ...

RFI draft: Please revise Details 17, 18, and 19 to provide positive lateral tension ties (e.g., Simpson DTT1Z or DTT2Z hold-downs) spaced appropriately to connect the exterior balcony and dropped corridor joists directly to the interior floor framing. This e...

Summary: The Cold-Formed Steel Framing general notes list reference standards AISI S200-12, AISI S211-07, AISI S212-07, and AISI S213-07. These individual standards were consolidated and superseded by AISI S240. The 2021 IBC Section 2211.1 explicitly requires that structural framing systems 'shall be in accordance with AISI S240.' The drawing does not reference AISI S240 at all. Additionally, for seismi...

Why it matters: Referencing superseded standards that are not recognized by the 2021 IBC will result in plan check rejection by the building official. Designs prepared to older AISI S200-series standards may not satisfy current code provisions consolidated in AISI S240 and AISI S400, particularly for seismic det...

Suggested next step: Request the Structural Engineer of Record update the Cold-Formed Steel Framing reference standards to cite AISI S240 for structural framing design per IBC Section 2211.1, and AISI S400 for seismic force-resisting system design per IBC Section 2211.1.1. Confirm that all cold-fo...

RFI draft: Request the Structural Engineer of Record update the Cold-Formed Steel Framing reference standards to cite AISI S240 for structural framing design per IBC Section 2211.1, and AISI S400 for seismic force-resisting system design per IBC Section 2211...

Summary: The Wood Joist Schedule and Wood Beam Schedule specify joist hangers that are one nominal lumber depth too small for the corresponding member sizes. J01 (2x8 DF #2) is assigned an LUS26 hanger (designed for 2x6 depth), J02 ((2)2x8 DF #2) is assigned an LUS26-2 hanger (designed for double 2x6 depth), J06 (2x10 DF #2) is assigned an LUS28 hanger (designed for 2x8 depth), and B02 ((2)2x8 DF #2) is...

Why it matters: J01 and J02 are the most commonly used joist types across the Level 5 framing plan, both specified at 16" OC throughout multiple bays of the building. J06 is used at all balcony locations. This systematic hanger mismatch would be discovered during framing when joists physically do not fit the und...

Suggested next step: Request the structural engineer of record verify and correct the joist hanger designations in both the Wood Joist Schedule and Wood Beam Schedule. Based on member sizes and the hanger naming convention used consistently throughout the schedules, the following corrections appea...

RFI draft: Request the structural engineer of record verify and correct the joist hanger designations in both the Wood Joist Schedule and Wood Beam Schedule. Based on member sizes and the hanger naming convention used consistently throughout the schedules, t...

Summary: The Tension Development and Lap Splice Length schedule (Detail 1/S5.21) for 12" CMU at f'm=2000 PSI shows development/lap splice lengths that are shorter than those for f'm=2500 PSI, which is physically impossible. Per TMS 402 Equation 6-1 (referenced by IBC Section 2108.2), development length is inversely proportional to √f'm, so lower masonry compressive strength must produce equal or longer ...

Why it matters: If contractors use these incorrect (undersized) lap splice lengths for 12" CMU walls designed with f'm=2000 PSI, the reinforcement will have inadequate development, potentially compromising the structural capacity of the masonry walls. Per IBC Section 2108.1, masonry strength design must comply w...

Suggested next step: Request the structural engineer review and correct the 12" CMU development/lap splice length values for f'm=2000 PSI in Schedule 1/S5.21. The current values are demonstrably lower than the f'm=2500 PSI values and show edge values less than center values, both of which are impo...

RFI draft: Request the structural engineer review and correct the 12" CMU development/lap splice length values for f'm=2000 PSI in Schedule 1/S5.21. The current values are demonstrably lower than the f'm=2500 PSI values and show edge values less than center ...

Summary: The Wood Stud Wall Schedule specifies exterior wall studs as "DF" (Douglas Fir) without any fire-retardant treatment designation. Note 3 confirms that "DF" DENOTES DOUGLAS FIR, which is untreated combustible lumber. Note 8 addresses FRT treatment but limits it to sheathing only, stating "WHERE REQUIRED IN TYPE IIIA CONSTRUCTION, EXTERIOR PLYWOOD TO BE FRT TREATED." IBC Section 602.3 requires th...

Why it matters: Using non-FRT wood framing in exterior walls of a Type IIIA building violates the fundamental construction type classification. Per Table 601, Type IIIA exterior bearing walls require a 2-hour fire-resistance rating, and Section 602.3 only permits FRT wood (not untreated wood) within these assemb...

Suggested next step: Confirm the building construction type. If the building is Type IIIA as referenced in Note 8, revise the Wood Stud Wall Schedule to specify fire-retardant-treated (FRT) Douglas Fir lumber for all wood framing members (studs, plates, blocking) within exterior wall assemblies, i...

RFI draft: Confirm the building construction type. If the building is Type IIIA as referenced in Note 8, revise the Wood Stud Wall Schedule to specify fire-retardant-treated (FRT) Douglas Fir lumber for all wood framing members (studs, plates, blocking) with...

Summary: The Wood Beam Schedule specifies built-up posts that are physically smaller in net dimension than the beams and hangers they are meant to support. Beam B10 is a 7"-thick PSL requiring a 7"-wide hanger, but its permitted supporting posts are only (2) 2x6 (5.5" maximum dimension) or (4) 2x4 (6.0" maximum dimension). Similarly, Beam B04 is 5.25" thick, but a permitted post is (4) 2x4 (3.5" depth i...

Why it matters: Because the actual net dimensions of the beams exceed the dimensions of the specified supporting posts, the beams will overhang their supports by up to 3.5 inches. Additionally, the hangers sized for these beams (e.g., HU410-2 for B10) will physically overhang the specified posts, making it impos...

Suggested next step: Please revise the built-up post sizes for B04 and B10 to ensure their actual net dimensions provide full solid bearing for the supported beams and adequate face width for the specified hangers to attach. A custom post size or steel column may be necessary for the 7"-thick B10 ...

RFI draft: Please revise the built-up post sizes for B04 and B10 to ensure their actual net dimensions provide full solid bearing for the supported beams and adequate face width for the specified hangers to attach. A custom post size or steel column may be n...

Summary: The Level 3 Shearwall Plan North shows a shearwall designated 'SW-3' with a length of only 0'-5" (5 inches). Per IBC Section 2305.1, wood-frame shear walls must be designed and constructed in accordance with AWC SDPWS. Per IBC Section 2305.3, shearwall deflection is calculated using Equation 23-2 where 'b' (shear wall length in feet) appears in the denominator of two terms: 8vh³/EAb and dah/b. ...

Why it matters: A shearwall segment of only 5 inches cannot provide meaningful lateral resistance. This is very likely a dimensioning error — possibly intended to be 10'-5" given that adjacent bays on the same plan show shearwalls with similar dimensions (e.g., SW-3 10'-5" in adjacent tiles). If constructed as d...

Suggested next step: Request the structural engineer of record confirm the intended length of the shearwall designated SW-3 with the 0'-5" dimension shown on the Level 3 Shearwall Plan North. If this is a drafting error, request a corrected dimension and revised drawing. Verify that the corrected ...

RFI draft: Request the structural engineer of record confirm the intended length of the shearwall designated SW-3 with the 0'-5" dimension shown on the Level 3 Shearwall Plan North. If this is a drafting error, request a corrected dimension and revised drawi...