Structural Calculations Package: 25 Issues Found

Summary: The Roof Framing Plan on sheet S2.0 consistently labels the roof rafters as '2x8 RAFTERS AT 24' O.C.' across the entire shed roof. However, Detail 6 on sheet S2.1, which is the Grid B Bearing Wall section detail showing the connection of those same rafters at the interior bearing wall, labels them as '2x8 RAFTERS AT 16' O.C.' This is a direct...

Why it matters: This discrepancy is critical because rafter spacing directly affects structural load distribution, lumber quantities, connection hardware requirements, and the adequacy of the bearing wall and ridge beam supporting the rafters. If the correct spacing is 16' O.C., the framing contractor following the 24' O.C. plan will under-frame the roof; if...

Suggested next step: Please clarify the correct rafter spacing for the shed roof. The Roof Framing Plan (S2.0) indicates 2x8 rafters at 24' O.C., while Detail 6/S2.1 (Grid B Bearing Wall) indicates 2x8 rafters at 16' O.C. Please confirm which spacing is correct and revise the conflicting drawing accordingly. If different spacing zones exist, please identify them on...

RFI draft: Please clarify the correct rafter spacing for the shed roof. The Roof Framing Plan (S2.0) indicates 2x8 rafters at 24' O.C., while Detail 6/S2.1 (Grid B Bearing Wall) indicates 2x8 rafters at 16' O.C. Please confirm which spacing is correct and revise the conflicting drawing accordingly. If...

Summary: The Loft Framing Plan shows a 7'-0' shear wall segment near Grid 3 with a triangular marker labeled '1', indicating Shear Wall Type 1 (allowable shear 260 plf). However, the specification calculation for Grid 3 (SB35) determines a unit shear demand of 268 plf, which exceeds the 260 plf capacity of Type 1 and requires Shear Ply Type 2 (allowable...

Why it matters: Using Shear Wall Type 1 where Type 2 is required means the wall has insufficient lateral shear capacity (260 plf provided vs. 268 plf required). This is a code-compliance deficiency that would fail plan check or field inspection. During a seismic or wind event, the under-designed shear wall could fail, posing a life-safety risk. Correcting this...

Suggested next step: Please confirm that the shear wall along Grid 3 (7'-0' segment) should be designated as Shear Wall Type 2 per the shear wall calculations (SB35, unit shear = 268 plf). If so, please revise the Loft Framing Plan to show a Type 2 shear wall marker at this location, and confirm that the associated nailing (8d @ 4' EN, 16d @ 4' bottom plate), top...

RFI draft: Please confirm that the shear wall along Grid 3 (7'-0' segment) should be designated as Shear Wall Type 2 per the shear wall calculations (SB35, unit shear = 268 plf). If so, please revise the Loft Framing Plan to show a Type 2 shear wall marker at this location, and confirm that the associated...

Summary: The design criteria note A.1 explicitly states the governing code as 'CODE = 2022 CALIFORNIA RESIDENTIAL CODE (CRC) / 2022 CALIFORNIA BUILDING CODE (CBC),' and General Note B.1 requires compliance with the 2022 editions. The applicable building code for this review is the 2025 California Residential Code, which requires in Section R301.1 that...

Why it matters: This code edition discrepancy would result in plan check rejection by the building department, causing significant permitting delays. All design criteria, load tables, section citations, and prescriptive requirements referenced throughout the structural notes and details must be verified and updated against the 2025 CRC. Any substantive changes...

Suggested next step: Confirm which code edition is applicable for this project. If the 2025 California Residential Code and 2025 California Building Code are in effect, update all code edition references in Design Criteria note A.1 and General Note B.1, and verify all section and table citations throughout the structural notes (including references to CBC Table...

RFI draft: Confirm which code edition is applicable for this project. If the 2025 California Residential Code and 2025 California Building Code are in effect, update all code edition references in Design Criteria note A.1 and General Note B.1, and verify all section and table citations throughout the...

Summary: The roof framing plan identifies the 6/S2.1 condition with '2x8 RAFTERS AT 24\' O.C.', but Detail 6/S2.1 'GRID B BEARING WALL' shows '2x8 RAFTERS AT 16\' O.C.' for that same referenced roof condition. The rafter spacing is therefore not coordinated between the plan and the referenced detail.

Why it matters: This creates uncertainty for framing layout, material quantities, sheathing support, and inspection because the roof could be built with two different rafter spacings at the same condition.

Suggested next step: Please confirm whether the roof at Detail 6 / GRID B BEARING WALL is to use 2x8 rafters at 24' O.C. or 16' O.C., and revise the roof framing plan or the detail so one spacing governs.

RFI draft: Please confirm whether the roof at Detail 6 / GRID B BEARING WALL is to use 2x8 rafters at 24' O.C. or 16' O.C., and revise the roof framing plan or the detail so one spacing governs.

Summary: The earthwork note permits footings to bear on compacted engineered fill, while the foundation design criteria require the footing to be embedded into firm native material. The drawing therefore authorizes a footing bearing condition that does not match the specification basis for foundation support.

Why it matters: Foundation bearing conditions directly affect excavation, inspection, and footing performance. Leaving both instructions in the contract set can lead to field preparation under one requirement and inspection against another, causing delay and possible footing rework.

Suggested next step: Revise the footing support note so it matches SH25, or issue a written clarification identifying where compacted engineered fill is permitted for footing bearing and what approved criteria apply.

RFI draft: Revise the footing support note so it matches SH25, or issue a written clarification identifying where compacted engineered fill is permitted for footing bearing and what approved criteria apply.

Summary: The perimeter footing detail explicitly allows the footing to bear on 'COMPACTED FIRM NATIVE MATERIAL OR ENGINEERED FILL.' The foundation design criteria require continuous footings to be '12 in below undisturbed ground surface' and to 'Embed 12\' into Firm Native Material.' Allowing engineered fill in this typical continuous footing detail...

Why it matters: This changes the basis of the foundation design and can lead to permit review comments or field delays if footing excavation encounters fill instead of native bearing. If engineered fill is intended, the foundation criteria and approval basis need to be revised accordingly before construction.

Suggested next step: Please confirm whether continuous perimeter footings are allowed to bear on engineered fill. If not, revise the perimeter footing detail to match the foundation criteria requiring '12 in below undisturbed ground surface' and 'Embed 12\' into Firm Native Material.' If engineered fill is intended to be acceptable, provide revised foundation...

RFI draft: Please confirm whether continuous perimeter footings are allowed to bear on engineered fill. If not, revise the perimeter footing detail to match the foundation criteria requiring '12 in below undisturbed ground surface' and 'Embed 12\' into Firm Native Material.' If engineered fill is intended...

Summary: The Roof Framing Plan on sheet S3.0 specifies rafters at 24' on center ('2x12 RAFTERS AT 24' O.C.'), and Detail 4/S3.1 (TYP OFFSET RIDGE) on sheet S3.1 also shows rafters at 24' O.C. However, Detail 5/S3.1 (TYP EAVE) on the same sheet S3.1 specifies rafters at 16' on center ('2x RAFTERS AT 16' O.C.'). Since the eave detail is called out from...

Why it matters: This discrepancy has significant implications for construction. If the contractor follows the 16' O.C. spacing from the eave detail, approximately 50% more rafters would be installed than what the plan intends, increasing material and labor costs. If the contractor follows the 24' O.C. plan spacing, the eave connection detail may not perform as...

Suggested next step: Please clarify the correct rafter spacing for the Saltbox roof. The Roof Framing Plan (S3.0) and Detail 4/S3.1 (TYP OFFSET RIDGE) indicate 2x12 rafters at 24' O.C., while Detail 5/S3.1 (TYP EAVE) indicates 2x rafters at 16' O.C. Which spacing is correct, and should the eave detail or the plan be revised?

RFI draft: Please clarify the correct rafter spacing for the Saltbox roof. The Roof Framing Plan (S3.0) and Detail 4/S3.1 (TYP OFFSET RIDGE) indicate 2x12 rafters at 24' O.C., while Detail 5/S3.1 (TYP EAVE) indicates 2x rafters at 16' O.C. Which spacing is correct, and should the eave detail or the plan be...

Summary: Detail 5/S3.1 (TYP EAVE) calls out '2x RAFTERS AT 16' O.C.' However, the specification structural analysis for the Typ Saltbox Rafter (SB5) was performed with rafters spaced at 24.0' c/c. Additionally, Detail 4/S3.1 (TYP OFFSET RIDGE) on the same sheet correctly shows '2x RAFTERS AT 24' O.C.' This creates a direct conflict between two typical...

Why it matters: If the contractor follows the TYP EAVE detail and installs rafters at 16' O.C. instead of 24' O.C., this would result in 50% more rafters than designed, causing material cost overruns and unnecessary labor. Conversely, if the contractor notices the discrepancy between the two details, it will likely cause a construction delay pending an RFI...

Suggested next step: Request clarification on the correct rafter spacing. The specification analysis (SB5) designs the typical saltbox rafter at 24.0' c/c, and Detail 4/S3.1 (TYP OFFSET RIDGE) shows 24' O.C., while Detail 5/S3.1 (TYP EAVE) shows 16' O.C. Please confirm the correct spacing and revise the TYP EAVE detail accordingly.

RFI draft: Request clarification on the correct rafter spacing. The specification analysis (SB5) designs the typical saltbox rafter at 24.0' c/c, and Detail 4/S3.1 (TYP OFFSET RIDGE) shows 24' O.C., while Detail 5/S3.1 (TYP EAVE) shows 16' O.C. Please confirm the correct spacing and revise the TYP EAVE...

Summary: The roof framing plan for the Saltbox labels the roof framing as '2x12 RAFTERS AT 24\' O.C.' and places a '5 / S3.1' callout at the eave condition. However, Detail 5 'TYP EAVE' specifies '2x RAFTERS AT 16\' O.C.' for that called-out condition. The referenced detail and the plan do not agree on the roof rafter spacing.

Why it matters: This creates uncertainty for framing layout at the roof edge and can lead to inconsistent installation, rework, and inspection comments if different spacings are used in the field.

Suggested next step: Please confirm the required Saltbox roof rafter spacing at the locations tagged 5/S3.1. Should Detail 5 be revised to 24' o.c. to match the roof framing plan, or should the roof framing plan be revised to 16' o.c. at those eave conditions?

RFI draft: Please confirm the required Saltbox roof rafter spacing at the locations tagged 5/S3.1. Should Detail 5 be revised to 24' o.c. to match the roof framing plan, or should the roof framing plan be revised to 16' o.c. at those eave conditions?

Summary: The loft framing plan shows a triangular wall tag '1' on the 7'-0' wall segment at the bottom of the lower-right projection. SB35 states 'Length of walls (ft) 7.0' and 'Unit Shear = 268 plf Use Shear Ply Type 2'. The drawn wall designation therefore conflicts with the specified shear-wall type for the 7.0-foot Saltbox wall.

Why it matters: This is a significant structural conflict because SB36 lists Mark 1 at 260 plf, which is less than the 268 plf demand in SB35. If constructed per the drawn '1' tag, the 7'-0' wall would be underdesigned for the specified lateral load and could require field strengthening or redesign.

Suggested next step: Please confirm the required designation for the 7'-0' wall segment at the bottom of the lower-right projection. Revise the plans to Shear Ply Type 2 to match SB35, or issue revised calculations demonstrating that the drawn '1' tag is acceptable.

RFI draft: Please confirm the required designation for the 7'-0' wall segment at the bottom of the lower-right projection. Revise the plans to Shear Ply Type 2 to match SB35, or issue revised calculations demonstrating that the drawn '1' tag is acceptable.

Summary: The structural notes identify the project code basis as the 2022 California Residential Code and 2022 California Building Code. The structural calculation package states the analysis and design are in accordance with IBC 2018 and uses IBC 2018 load combinations. The drawing therefore cites a different governing code edition than the...

Why it matters: A mismatched code basis can trigger plan review comments, require recalculation or sheet revisions, and create uncertainty over which structural load and detailing criteria govern construction.

Suggested next step: Please confirm the governing code edition for the project and revise the structural notes or the calculation package so the drawings and structural design documents use one consistent code basis.

RFI draft: Please confirm the governing code edition for the project and revise the structural notes or the calculation package so the drawings and structural design documents use one consistent code basis.

Summary: The structural notes on the sheet identify the governing code as 2022 CRC/CBC, but the provided structural analysis text states that the design was performed in accordance with IBC 2018. That is a direct mismatch in the project's code basis between the drawings and the supporting design documents.

Why it matters: A conflicting code basis can trigger permit comments and force recalculation or note revisions because the reviewer and contractor cannot verify that the shown structural design criteria, member design, and connection design are based on the same governing code edition.

Suggested next step: Please confirm the governing structural code edition for this project and revise either the structural notes or the structural analysis package so both documents cite the same code basis before permit approval and construction.

RFI draft: Please confirm the governing structural code edition for this project and revise either the structural notes or the structural analysis package so both documents cite the same code basis before permit approval and construction.

Summary: The Loft Framing Plan on sheet S1.0 specifies '2x8 CLG JSTS AT 16' O.C.' for the loft ceiling joists. Detail 8/S1.1 (LOFT TO WALL CONN) on sheet S1.1 shows these ceiling joists connected with 'LUS26' joist hangers at both the wall ledger end and the 6x beam end. Simpson Strong-Tie LUS26 hangers are designed to support 2x6 members, not 2x8...

Why it matters: Using undersized joist hangers (LUS26 instead of LUS28) results in insufficient seat depth and reduced allowable load capacity at the loft joist-to-ledger and joist-to-beam connections. This could lead to structural inadequacy at the loft framing, potential rejection during framing inspection, and construction delays. Notably, elsewhere on the...

Suggested next step: Request the structural engineer clarify the correct joist hanger type for the loft ceiling joists at the loft-to-wall connection (Detail 8/S1.1). If the joists are 2x8 as shown on the Loft Framing Plan, the LUS26 hangers should be revised to LUS28 at both the ledger and beam connections. Alternatively, if the ceiling joists should be 2x6, the...

RFI draft: Request the structural engineer clarify the correct joist hanger type for the loft ceiling joists at the loft-to-wall connection (Detail 8/S1.1). If the joists are 2x8 as shown on the Loft Framing Plan, the LUS26 hangers should be revised to LUS28 at both the ledger and beam connections....

Summary: The loft-to-wall connection detail shows 'LUS26' at the ends of '2x CEILING JOISTS PER PLAN.' The structural design identifies the 'Typ Clg Jst' as '2x8 (1-1/2\'x7-1/4\')' with 'Supports: All - Hanger.' The hanger callout in the detail is not coordinated with the 2x8 joist design.

Why it matters: This creates a high risk of ordering and installing the wrong joist hanger for the loft framing, which can stop framing inspection and force connector substitutions in the field.

Suggested next step: Confirm the required hanger model for the 2x8 typical ceiling/loft joists at the loft-to-wall connection and revise the detail if LUS26 is not intended.

RFI draft: Confirm the required hanger model for the 2x8 typical ceiling/loft joists at the loft-to-wall connection and revise the detail if LUS26 is not intended.

Summary: The drawing's Design Criteria (Section A, Item 1) explicitly identifies the design code as 'CODE = 2022 CALIFORNIA RESIDENTIAL CODE (CRC) / 2022 CALIFORNIA BUILDING CODE (CBC)' and the General Notes (Section B, Item 1) states 'ALL PROJECTS SHALL COMPLY WITH THE 2022 CALIFORNIA RESIDENTIAL CODE (CRC) AND/OR 2022 CALIFORNIA BUILDING CODE (CBC).'...

Why it matters: Referencing an outdated code edition on construction documents would result in plan check rejection by the building department, causing significant permitting delays. The 2025 CBC incorporates ASCE 7-22, which introduces substantial changes from ASCE 7-16 referenced by the 2022 CBC, including updated seismic hazard maps and the new multi-period...

Suggested next step: Request the structural engineer of record update all design criteria, code references, and structural calculations to comply with the 2025 California Building Code and 2025 California Residential Code. This should include verification of seismic design parameters (Ss, S1, SDS, SD1) per updated ASCE 7-22 hazard maps, confirmation of the...

RFI draft: Request the structural engineer of record update all design criteria, code references, and structural calculations to comply with the 2025 California Building Code and 2025 California Residential Code. This should include verification of seismic design parameters (Ss, S1, SDS, SD1) per updated...