Layer 4: what the quality manual has to contain (Montana factory-built buildings)

Research pass, 13 Sep 2026. Every requirement below carries a source URL and the date it was fetched. Where I could not confirm something I say NOT CONFIRMED and leave it for someone to close out. Other layers cover the Montana statutes, the approval process and the applicable codes. This file is only about the manual itself and the quality system it describes.

The one-line answer: Montana does not write its own quality-manual content rule. It points at Chapter 5 of ICC/MBI 1205-2021, which it has adopted by reference, and adds a short published list of its own on the bureau's web page. So the manual is written to ICC/MBI 1205 Chapter 5, section by section, with the Montana web-page items folded in.

1. What Montana specifically requires#

1.1 The rule#

ARM 24.301.1223, IN-PLANT QUALITY ASSURANCE MANUAL (new, effective 21 Sep 2024):

1. The manufacturer submits a quality assurance manual outlining a program of quality assurance prior to or with its first request for plan review, including the manual review fee in ARM 24.301.1261.
2. "The quality assurance manual must include all applicable items as listed in chapter 5 of the ICC/MBI 1205 Standard and be reviewed and approved by the bureau prior to the approval of plan review."
3. When the manual is revised, one copy of the revised manual goes to the bureau for review, with the review fee again.

Authority MCA 50-60-203 and 50-60-401; implements 50-60-203, 50-60-401 and 50-60-402. Source: https://www.law.cornell.edu/regulations/montana/Mont-Admin-r-24.301.1223 (fetched 13 Sep 2026).

Two things fall out of that. The manual is a gate on plan review, not something you do afterwards. And every revision costs a fee and a re-review, so the manual should be written so that ordinary production changes do not force a revision (see section 7 note on thin sections).

1.2 Which edition of the standard#

ARM 24.301.1203 adopts and incorporates by reference:

• ICC/MBI 1200 Standard for Off-site Construction: Planning, Design, Fabrication and Assembly, 2021 edition
• ICC/MBI 1205 Standard for Off-site Construction: Inspection and Regulatory Compliance, 2021 edition

No Montana amendments, deletions or exceptions are stated in that rule. Effective 21 Sep 2024. Source: https://www.law.cornell.edu/regulations/montana/Mont-Admin-r-24.301.1203 (fetched 13 Sep 2026).

ARM 24.301.1201 lists the whole adopted set for factory-built buildings: IBC or IRC, NEC, IMC, UPC, IECC, IWUIC, and the two ICC/MBI standards through 24.301.1203. Source: https://www.law.cornell.edu/regulations/montana/Mont-Admin-r-24.301.1201 (fetched 13 Sep 2026).

There is a third standard in the family, ICC/MBI 1210-2023 (energy and water), which appears in ICC's 2025 collected volume. Montana does not adopt 1210 in ARM 24.301.1203. Source (existence of 1210-2023): https://codes.iccsafe.org/content/ICCMBIOSCS2023P1 (title seen in search results, 13 Sep 2026; the ICC Digital Codes pages themselves block automated fetching).

1.3 The bureau's own published list#

The Building Codes Bureau's Factory-Built Buildings page carries its own list of what the quality control manual must include. Quoting the page's items:

• Scope and purpose of the manual
• Inspection procedure for basic materials
• Material storage and stock rotation procedure
• Drawings and bill of material
• Types and frequency of product inspection
• Sample of inspection control form used
• Record-keeping procedures for quality control forms
• List of major pieces of production equipment
• Where responsibility for quality control program lies
• Test procedural manual, including electrical, gas line, water systems and drain/vent/plumbing fixture tests and type of test equipment used
• List of test equipment

Source: https://bsd.dli.mt.gov/building-codes-permits/permit-applications/factory-built-buildings/ (fetched 13 Sep 2026).

Note what this adds beyond ICC/MBI 1205: stock rotation, bill of material, and an explicit test procedural manual for the four wet and live trades (electrical, gas line, water, DWV and fixtures) with the test equipment named. Ken's shower house has all four. The house has all four. There is no way around writing that section.

The page also lists the approved third-party inspection agencies (16 agencies, page says last updated 1/28/26) and links the insignia application and the third-party inspector certification form.

1.4 Is there a Montana checklist or template?#

No published checklist or manual template was found. The bureau publishes the list above, the application form, the insignia application and the third-party inspector certification form. That is all. Marked NOT CONFIRMED that no internal checklist exists; the bureau may hand one out on request, and that is worth one phone call to (406) 841-2056 / buildingcodes@mt.gov before drafting.

For comparison, North Carolina does publish a "QC Manual Checklist" that manufacturers must complete and submit, and it rejects manuals that arrive without it. If Montana has an equivalent, asking for it is free. Source: https://www.ncosfm.gov/manufactured-bldg/modular-buildings/modular-manufacturer-approval-procedures (fetched 13 Sep 2026).

1.5 Fees and the mechanics of submission#

ARM 24.301.1261 sets the plan and system review fees. The one that matters here: Quality control manual review: $20. Third-party inspection agency application review: $20. Structural review $325 / $450 / $650 by part count, with plumbing, electrical and mechanical at $35 / $55 / $75 each. Resubmission or revision $20 to $125 by system. Plan supplement $20 per unit. Plan renewal $100, and approved units expire 31 December unless renewed. Source: https://www.law.cornell.edu/regulations/montana/Mont-Admin-r-24.301.1261 (fetched 13 Sep 2026).

The application form (APPLICATION FOR APPROVAL OF FACTORY BUILT BUILDING, Rev. 4/23) confirms the same $20 and says it is "Required with 1st submission OR if QC has changed." It also has a required third-party inspector block, and prints in capitals: "ALL INCOMPLETE APPLICATIONS WILL BE RETURNED UNPROCESSED." Source: https://bsd.dli.mt.gov/building-codes-permits/permit-applications/factory-built-buildings/FBBP_APPLICATION_ADOBE_F.pdf (fetched 13 Sep 2026).

1.6 The insignia rule, because the manual has to describe label control#

ARM 24.301.1243: the manufacturer applies for an insignia of approval for each individual unit, on the bureau form, with the insignia fee (ARM 24.301.1263), and the application must include the approved model number and the serial number or numbers for each unit the insignia will go on. The manufacturer receives the insignia from the bureau and is responsible for attaching it to each unit. An insignia must be used within 12 months of issuance or it is void, with no refund or credit. Source: https://www.law.cornell.edu/regulations/montana/Mont-Admin-r-24.301.1243 (fetched 13 Sep 2026).

That is the hook that makes the manual's serial-number system (ICC/MBI 1205 §501.13) and label control (§503.1) real: the serial number Ken stamps on a panel run has to be the same serial number that goes on the insignia application, and an unused insignia is money burned after a year.

2. The national reference documents, section by section#

2.1 ICC/MBI 1205-2021, Chapter 5, the one that governs#

Chapter 5 is titled REQUIREMENTS FOR COMPLIANCE ASSURANCE PROGRAM and has three sections: 501 General, 502 Materials Control, 503 Certification Label.

Source and a caveat on the text. ICC Digital Codes (codes.iccsafe.org) refuses automated fetching, so the section text below is taken from ICC's own posted approved draft ballot PDF for the standard, copyright 2021 International Code Council: https://www.iccsafe.org/wp-content/uploads/is_osmc/ICC1205-draft-ballot-apprvd.pdf (fetched 13 Sep 2026). Corroboration that the published 2021 edition uses the same numbering: ICC Digital Codes exposes section URLs ICC12052021P1-Ch05-Sec501.12 and ICC12052021P1-Ch05-Sec501.15 under "chapter-5-requirements-for-compliance-assurance-programs" (seen in search results 13 Sep 2026). Before the final drafting pass, buy the 2021 edition and check the numbering line by line. A manual that cites a section number the reviewer cannot find is an easy rejection.

Section 501, General:

Section 502, Materials Control:

Section 503, Certification Label:

That is the whole of what ARM 24.301.1223 points at. Twenty-two requirements. Everything else in this document is either Montana's own add-on, a supporting requirement from 1200, or good practice that makes the twenty-two defensible.

2.2 ICC/MBI 1200-2021, the plant and process side#

1200 is the planning, design, fabrication and assembly standard. Montana adopts it too, and several of its clauses land on the manual even though 1223 only names 1205.

Chapter 5, Manufacturing Plant:

• 503.1 Each manufacturing plant shall have an approved QA/QC plan in accordance with Chapter 5 of ICC 1205 prior to commencing fabrication or construction activities. That is the cross-reference that ties the two standards together.
• 503.2 A printed copy of the approved QA/QC plan shall be available in the plant for inspection at reasonable times without prior announcement.
• 504.1 The plant identifies a responsible party to implement the QA/QC processes, and that person "shall have the authority necessary to ensure compliance with this Standard." Quality personnel must demonstrate to the inspection agency adequate knowledge of the product, factory operations and the codes and standards, and the ability to perform their duties.
• 504.2 Observation of manufacturing and construction activities as often as necessary to ensure compliance with the plan.
• 504.3.1 The responsible party prepares verification documents per the approved plan.
• 504.3.2 All documentation is made available to the AHJ on request.
• 504.3.3 All documentation is retained not less than 12 months after delivery of the module, panel or component, unless the approved plan states a longer duration.
• 505.1 The plant does not restrict AHJ access at any time manufacturing is happening.
• 505.2 The plant notifies the AHJ before commencing fabrication on a project, per the approved plan.
• 506.1 All building materials protected from weather, moisture and contaminate sources per the material manufacturer's recommendations.

Chapter 6, Fabrication: 601.1 build to the approved plans; 602.1 identify each module or component; 603 deformation compatibility; 604.1 temporary supports and shoring to preserve the structure during manufacture, transportation and on-site storage; 605.1 stacking details including a maximum stack; 605.2 weather protection of stacked and stored units.

Chapter 7, Transportation and Storage: 701.1 the manufacturer provides, with each set of units, instructions covering transport, lifting and placement; 702 permitting, route width and height, gross weight; 703 method of transport (integrated chassis, separate trailer, or an accepted alternative); 704.1 the manufacturer creates with the erector a loading and unloading manifest that protects the units from stress and mechanical damage, and the erector details the unloading logistics and the crane type; 705 on-site staging, stacking to the manufacturer's details, weather and mechanical protection, and minimizing staging time.

Chapter 8, On-site Installation: 801.1 the manufacturer provides installation procedures and layout information; 802 foundation plan and loads; 803.1 the registered design professional details the required construction tolerances for fitting each module to each module and to the foundation, terms per ISO 6707-1:2020; 804.1 manufacturer instructions covering (1) connecting the modules or panelized systems for strength and rigidity, (2) maintaining the air barrier, vapor barrier, insulation, sheathing membrane, cladding, roofing and flashing at joints, (3) connecting ducting, piping and wiring and maintaining sealing and insulation, (4) fire separations and fire blocking between modules, (5) foundation loads, anchorage details and anchorage device capacity, (6) maximum foundation support and spacings, (7) connection of services, (8) everything else installed or completed on site.

Source for 1200: https://www.iccsafe.org/wp-content/uploads/is_osmc/ICC1200-draft-ballot-apprvd.pdf (fetched 13 Sep 2026), same draft-ballot caveat as above.

Why this matters for Ken directly. The house is a panelized system, not volumetric modules. The shower house is a complete unit on a skid, which behaves like a module. 1200 §803.1 and §804.1 are the on-site set instructions, and §804.1(1) is exactly the screwed edge-stud joint and §804.1(5) is exactly the slab anchor. Those are open items in wall-spec-v1.md §4 (items 2, 3, 6) and in pe-package.md. The manual cannot describe a set instruction that the PE has not yet defined.

2.3 HUD, 24 CFR 3282, the manufactured-housing analogue#

Not law for Ken (his product is a factory-built building under MCA Title 50 ch. 60, not a HUD-code manufactured home), but it is the oldest and most tested version of this idea in the United States and reviewers think in its vocabulary.

24 CFR 3282.203(c), verbatim on the manual's minimum contents:

The manufacturer shall submit to the DAPIA such information as the DAPIA may require in order to carry out quality assurance manual approvals. At a minimum, this information shall include the quality assurance manual for which approval is sought. That manual shall include the manufacturer's quality assurance program, an organizational chart showing the accountability, by position, of the manufacturer's quality control personnel, a description of production tests and test equipment required for compliance with the standards, a station-by-station description of the manufacturing process, a list of quality control inspections required by the manufacturer at each station, and identification by title of each person who will be held accountable for each quality control inspection.

Six elements: the program, the org chart with accountability by position, production tests and test equipment, station-by-station process, the inspection list per station, and a named title accountable for each inspection.

Also in the same section:

• (d) Supplementary information may be required "if the design information or the quality assurance manual is not complete or if any information is not in accordance with accepted engineering practice." That is the rejection clause, and it has the same two prongs everywhere: incomplete, or not good practice.
• (e) A change to an approved manual needs the approving agency's approval before production for sale.
• (g) A copy of the approved manual is kept in each plant, current and readily accessible.

Source (verbatim text, 4-1-24 CFR edition): https://www.govinfo.gov/content/pkg/CFR-2024-title24-vol5/pdf/CFR-2024-title24-vol5-sec3282-203.pdf (fetched 13 Sep 2026). Cross-check: https://www.law.cornell.edu/cfr/text/24/3282.203 (fetched 13 Sep 2026).

24 CFR 3282.204(b), the production side: the manufacturer makes the approved design and the quality assurance manual available to the in-plant agency, which performs an initial factory inspection. If the agency issues a deviation report, the manufacturer corrects, and only then does the agency issue the certification report. Labels come after the certification report is signed. Source: https://www.law.cornell.edu/cfr/text/24/3282.204 (fetched 13 Sep 2026).

The lesson transfers exactly: the manual is approved on paper, then a person walks the floor and checks that the plant can actually do what the paper says. Montana's third-party agency plays the same role.

2.4 IAS accreditation criteria, what an inspector looks for in a plant#

Two IAS documents are worth knowing.

IAS AC98, Accreditation Criteria for Inspection Agencies, based on ISO/IEC 17020, most recently updated June 2026. This is what accredits the agency Ken hires, not Ken's plant. It covers independence, personnel competence, inspection processes and the agency's own quality system. Source: https://www.iasonline.org/services/inspection-agencies/ (fetched 13 Sep 2026).

IAS AC157, Accreditation Criteria for Fabricator Inspection Programs for Reinforced and Precast/Prestressed Concrete, June 26 2024 edition, editorially revised 20 Aug 2025. This is the one that matters. It is the IBC §1704 "approved fabricator" route for a precast concrete plant, and its sections 4.3, 4.4 and 4.5 are effectively a concrete-plant quality system manual outline. Ken is not required to hold AC157, but if a reviewer or an engineer asks what a competent concrete plant's manual looks like, this is the public answer. Source: https://www.iasonline.org/wp-content/uploads/2025/09/AC157-Final-June-2024-ed20250820.pdf (fetched 13 Sep 2026).

AC157 §4.2, general requirements:

• 4.2.1 a documented management system, prepared in concert with an IAS-accredited inspection agency, signed and dated by an authorized officer.
• 4.2.2 key quality personnel. The Quality Control Manager is a full-time employee, PCI Level II certified (or an equivalent route), five years' experience in reinforced concrete products, a registered design professional or an allowed alternative, and is responsible for overall quality and workmanship, for maintaining the documented system, for monitoring its implementation, for periodic internal audits and for annual management reviews. The Quality Control Inspector is full-time and ACI-certified as a Concrete Construction technician/inspector (Level I if the plant does not do its own testing, Level II if it does) and ACI-certified as a Concrete Field Testing Technician. Technicians are certified as Concrete Sampling Technician and Concrete Strength Testing Technician, and trained for steel reinforcement.
• 4.2.3 structural welding generally in accordance with the welding code.
• 4.2.4 a daily production log recording activities and describing any problems or deficiencies found.
• 4.2.5 documented test procedures for all in-house tests; calibration traceable to nationally recognized standards; outside testing by an accredited laboratory.

AC157 §4.3, required data: name, address and phone of the facility; a floor plan; a list of major production equipment keyed to the floor plan; a list of typical items fabricated; required qualifications of the QC manager, inspectors and technicians; an organizational chart showing the relationships among management, QC manager, QC inspector and QC technicians; a list of approved vendors including testing agencies; a list of test and measuring equipment; an example of each form and report including the daily production log; an example of the contract-review data sheet.

AC157 §4.4, required statements: a policy statement that all activities are directed to meet the quality requirements and that the program elements are made known to all responsible personnel; the quality system is reviewed at least annually; notice before cancelling the inspection agreement; forwarding inspection reports that note major variations within 10 days; notifying the agency of extended plant closures and before resuming; notifying if unannounced follow-up inspections have not happened; promptly investigating and responding to complaints of noncompliance.

AC157 §4.5, required written procedures:

• 4.5.1 contract review (do we have the resources to do this job)
• 4.5.2 document control: approval of documents, only current approved documents in use, documents available everywhere they are needed
• 4.5.3 purchasing
• 4.5.4 subcontracting
• 4.5.5 product traceability to incoming raw materials, responsible QC personnel, plans and specifications, and quality records
• 4.5.6 process control: reinforcing steel placement, splicing and tying; concrete mixtures (the method of designing and verifying the mix, and verification before use with batching, mixing equipment, construction methods and curing environment representative of the plant); batching and mixing (proportioning method, mixing method for uniform consistency); placing (transport from mixer to forms, placement without segregation, consolidation, and a method to make sure the density of the strength test specimens is representative of the product); curing (method for the product and method for the test specimens); finishing (unformed surfaces, composite member surfaces, formed surfaces, and patching minor defects)
• 4.5.7 inspection and testing: incoming raw materials before they go into service; production methods with frequency and method for reinforcing placement, and frequency and method for the mix including unit weight of aggregates, moisture content, slump, air content, density (unit weight) of concrete, concrete temperature at placement, ambient temperature at placement, and compressive strength; and a method for verifying curing conditions
• 4.5.8 control of measuring and test equipment: calibration procedures and traceability of calibration records to nationally recognized standards; control of nonconforming product: identifying it and assigning its disposition
• 4.5.9 corrective action: investigating, documenting, correcting
• 4.5.10 handling and storage of incoming materials and finished products
• 4.5.11 internal audits: frequency, documentation method and content
• 4.5.12 control of quality records, minimum two years: in-house inspection reports, forms and checklists; mill test reports and certificates of compliance from vendors; copies of the inspection agency's reports; internal audit records; training records; evaluations of vendors and subcontractors
• 4.5.13 training: a procedure for training everyone whose work affects product quality, and a procedure for maintaining current personnel qualifications

Prestressing clauses (detensioning, elongation, initial and final load) do not apply to Ken. Everything else does, almost word for word.

3. Consolidated required-content outline#

Every section a compliant manual needs, with one line on what belongs in it, and where the requirement comes from. "MT" = the bureau's published list. "1205 §x" = ICC/MBI 1205-2021 Chapter 5. "1200 §x" = ICC/MBI 1200-2021. "HUD" = 24 CFR 3282.203(c). "AC157 §x" = the IAS fabricator criteria.

Items 25 and 26 are the two places where the standard list in the task brief goes beyond anything I could source for Montana. They are worth including in the manual anyway, because they cost a page each and they answer a question the reviewer will ask, but do not tell Ken they are required.

4. What a concrete plant adds on top of a normal modular manual#

A modular manual written for a stick-framed plant does not have a concrete section. Ken's does. These are the extra controls, with where each one comes from.

4.1 Mix design control#

Identify how the mix is designed and how it is verified, and verify it before use with batching, mixing equipment, construction methods and curing environment representative of what the plant actually does (AC157 §4.5.6.2). For cellular concrete specifically, mixture proportioning guidance comes from the foam concentrate manufacturer, and the proportions set the density and the strength; the user should test the proportions when nonstandard materials or special applications are involved (ACI 523.1R-06 §4.1). Each ingredient that does not meet a standard specification for compatibility should have the cellular concrete properties checked in actual mixtures per ASTM C796 and C869; cements vary within specification limits, so mill reports and test batches are the way to compare sources (ACI 523.1R-06 §4.2).

Practical effect: a change of cement source, or a change of foaming agent, is a mix requalification, not a purchasing decision. That belongs in the manual as a written trigger.

Source: https://my.civil.utah.edu/~bartlett/LCC/misc/523.1r-06-guide-for-cast-in-place-low-density-cellular-concrete.pdf (fetched 13 Sep 2026; a licensed copy of ACI 523.1R-06 hosted by the University of Utah. Buy the ACI copy before citing it in a submitted manual).

4.2 Batching records and calibration#

Materials are proportioned and batched directly into a specialized mixer; dry materials weighed on a calibrated scale, mixing water metered, preformed foam metered through a calibrated nozzle. The accuracy of each batching device is critical to the final density and its reproducibility, and each batching device (scales, water meter, foam-generating nozzle) should be calibrated before starting a project, and during a project if there is reason to (ACI 523.1R-06 §5.2). Mixing should be mechanical and uniform; excessive mixing may change density and consistency; standard concrete mixing equipment is normally not acceptable, a high-speed paddle or high-shear mixer is preferred (§5.3).

This is the single clearest calibration requirement in the whole concrete side, and it maps straight onto 1205 §501.14 and AC157 §4.5.8.1.

4.3 Density and wet unit weight checks#

Measuring cast density at the point of placement is the simplest and most convenient test for monitoring the quality of the placed material (ACI 523.1R-06 §4.3). The as-cast density should be monitored at the point of placement every 30 to 60 minutes, with allowance for density changes caused by placing methods or conditions such as pumping distance and extreme weather (§5.3). AC157 §4.5.7.2.4.5 lists density (unit weight) of concrete as an inspection item alongside slump, air content and temperature.

For Ken this is the check that keeps the whole model honest: concrete.densityPcf 35 and concrete.fillDensityPcf 30 are the basis for every dead load, every pick weight and the 33,366 lb transport figure in docs/showerhouse-takeoff.json. The plant test is ASTM C138/C138M fresh density, already in standards-register.md under "Plant density and strength QC". The manual needs a stated acceptance band around 35 and 30 pcf, and that band is a PE decision, not a plant decision.

4.4 Cylinder sampling and break records#

Cylinder specimens for compressive strength, usually 3 x 6 in., should be cast at the same time that the periodic density tests are performed, covered and stored in a protected area for at least 24 hours before transport to the lab, and tested in accordance with ASTM C796 (ACI 523.1R-06 §4.3). test-matrix.md already names ASTM C495/C495M as the compressive strength method for lightweight insulating concrete at this density, with ASTM C513 for cores cut from a cast panel later, and calls for at least 3 cylinders per age per mix at 7 and 28 days. The manual needs the sampling frequency (per batch, per bed, per day, per cubic yard), who casts and cures the specimens, where the breaks are done, and what the plant does when a break comes in low.

AC157 §4.5.6.4.4 adds a requirement that is easy to miss: a stated method to make sure the density of the strength test specimens is representative of the product. With foam concrete that is a real risk, not a formality.

4.5 Cure time and temperature records#

AC157 §4.5.6.5 requires a written method of curing the product and a separate written method of curing the test specimens, and §4.5.7.2.5 requires an inspection method to verify proper curing conditions. ACI 523.1R-06 §5.6 advises water curing or a curing compound where rapid drying is expected, and compatibility of any curing compound with the finish that follows. §5.7 covers cold weather: when ambient temperature below 32 F is predicted within 8 hours after placement, use Type III cement or Type I with heated mixing water; do not mix or place during freezing weather, rain or snow, or over standing water, snow or ice. §5.8 covers hot weather above 100 F.

Montana makes §5.7 a year-round operating reality, not an exception clause. The model's concrete.cureDaysBeforeSet is 7 days before the panels are stood, so the cure log has to prove 7 days at an acceptable temperature for the specific bed and slot each panel came out of.

4.6 Bed and form control#

Not covered by ACI 523.1R (which is a cast-in-place guide). The nearest published requirements are AC157 §4.5.6.4 (placing: transport from mixer to forms, placing without segregation, consolidation) and §4.5.6.6 (finishing formed and unformed surfaces). The form and bed dimension check itself, and the tolerance on slot width and length, is NOT CONFIRMED against a published standard for this product. The usual home for it is a precast plant manual; see §4.10 below on PCI MNL-116.

Ken's bed is a 4-slot bed with a movable end board, sized for the 12'-6" wall-A panel and shortened for the 10' panels and for the shower-house cut panels (wall-spec-v1.md §2, showerhouse.md). The manual needs a pre-pour bed check per cycle: slot dimensions, liner condition, edge form straightness and the end board position for any cut panel.

4.7 Mesh, embedment and lifting-insert placement#

AC157 §4.5.6.1 and §4.5.7.2.1 cover placement of reinforcing steel, the method of tying, freedom from contamination, and the frequency and method of inspecting placement. That maps onto the basalt mesh, the 1-1/2" cold-rolled channel rows, the studs and track set into the wet skin pour, the cast-in sleeves for the shower house plumbing, and the lifting inserts.

The lifting insert is the highest-consequence placement check in the plant, because the roof strip pick is 10,617 lb and the floor panel pick is 5,510 lb (test-matrix.md). standards-register.md already routes insert capacity through PCI MNL-120 factors and an ASTM E488 pull-out in our concrete, because published insert values are for normal-weight concrete. The manual should make insert type, embedment depth and position a hold point with a sign-off, not a general workmanship item.

4.8 Panel dimensional tolerances#

NOT CONFIRMED for this product. ICC/MBI 1200 §308.4 is titled "Tolerances for panelized system construction" and §803.1 puts the on-site fit tolerances on the registered design professional, with terms per ISO 6707-1:2020. Neither gives numbers for a cellular concrete panel. ACI 523.1R-06 gives a casting tolerance only for geotechnical grade (0.1 ft to final grade, §5.5), which is not applicable. The dimensional tolerance table for Ken's panels has to come from the PE or be adopted from a precast plant standard and then accepted by the PE. This is a real gap and it should be on the PE package question list.

4.9 Surface and defect acceptance criteria#

AC157 §4.5.6.6.4 requires a written method of patching minor defects, which implies a stated line between a minor defect that may be patched and a defect that makes the panel nonconforming. That line is NOT CONFIRMED from any published source for cellular concrete. It matters more here than in ordinary precast because the cast finish face is the interior finish face of the building (wall-spec-v1.md §1), so the acceptance criteria are partly cosmetic and partly structural. Ken has to write them, photograph examples, and get the PE and ideally the third-party agency to agree before the first customer does.

4.10 Where these come from: ACI 523 versus a PCI plant model#

Honest summary of what is and is not published:

• ACI 523.1R-06, Guide for Cast-in-Place Low-Density Cellular Concrete. Covers oven-dry densities of 50 lb/ft3 or less, so it covers Ken's 35 and 30 pcf. It is the source for mix proportioning guidance (§4.1), ingredient compatibility with C796 and C869 (§4.2), cast density monitoring and 3 x 6 in. cylinders (§4.3), material storage (§5.1), batching device calibration (§5.2), mixing and the 30 to 60 minute density check (§5.3), placing by progressive-cavity or peristaltic pump (§5.4), curing (§5.6) and cold and hot weather (§5.7, §5.8). It is a cast-in-place guide and it is a guide, not a code, so it advises rather than requires. Source: https://www.concrete.org/publications/internationalconcreteabstractsportal.aspx?m=details&id=18403 (fetched 13 Sep 2026).
• ACI 523.2R-96 (now designated ACI PRC-523.2-96), Guide for Precast Cellular Concrete Floor, Roof, and Wall Units. This is the closest published document to Ken's actual product: precast floor, roof and wall slabs at oven-dry weights of 50 pcf or less, covering materials, fabrication, properties, design and handling. I could not obtain the full text, so its section-level content is NOT CONFIRMED. Buy it. It is the first thing to read before the concrete chapter of the manual is written. Source: https://www.concrete.org/publications/internationalconcreteabstractsportal.aspx?m=details&ID=5227 (fetched 13 Sep 2026).
• PCI MNL-116, Manual for Quality Control for Plants and Production of Structural Precast Concrete Products, MNL-116-21. This is the plant certification model. The PCI bookstore page says it is "a strong foundation for a plant's quality system" and that the first part contains Divisions 1 through 7, which form the basis for PCI Plant Certification in the structural product groups, with appendices containing sample record forms. The division titles are NOT CONFIRMED: I could not retrieve the table of contents from a public source. standards-register.md already names MNL-116 as the template for the plant manual, which is a sound instinct, but the actual division structure has to be read from a purchased copy before it is used as the skeleton. Source: https://www.pci.org/PCI/PCI/Bookstore/Item_Detail.aspx?iProductCode=MNL-116-21&Category=QA (fetched 13 Sep 2026).
• IAS AC157 is the freely published document that most nearly states what a concrete plant's quality manual must contain, and it is the one this section leans on hardest. PCI and IAS have a cooperation agreement letting PCI-certified plants apply that certification toward AC157 accreditation, which tells you the two models are close. Source: https://www.pci.org/PCI/PCI/PCI-Certification/Plant_Certification/IAS-AC157.aspx (fetched 13 Sep 2026).

Bottom line on sourcing: the concrete QC content Ken can cite with confidence today comes from ACI 523.1R-06 (mix, batching, density, cylinders, curing, weather) and IAS AC157 (the written procedures, personnel, records and calibration). Dimensional tolerance and surface defect acceptance have no public source for this product and must be authored and stamped.

5. The records package: every form and log the plant needs on day one#

Generic names. None of these is copied from any company's forms. ICC/MBI 1205 §501.17 requires that every form appear in the manual with a written procedure for its use, and AC157 §4.3.11 requires an example of each form and report, so this list is itself a deliverable, not just a plan.

Materials and purchasing

Concrete

Production

Shipping, storage and site

Program administration

That is roughly 30 forms. A small plant can run all of them on paper in two binders plus a spreadsheet, and several of them can be combined onto one sheet, but the panel traveler, the batch ticket, the cast density log, the cure log and the insignia control log should stay separate, because each one answers a different question that an inspector will ask on a different day.

6. Why quality manuals get rejected, and why plants lose approval#

Sourced where I could find a source. Where a reason is an inference from a requirement rather than a published rejection statistic, I say so.

Rejected at review:

1. Incomplete or not current. North Carolina states it flatly: "Any manual determined to be incomplete or not current will result in the automatic disapproval of the plans under review." HUD's version is the same test in 24 CFR 3282.203(d): supplementary information may be required "if the design information or the quality assurance manual is not complete or if any information is not in accordance with accepted engineering practice." Montana's application form says incomplete applications are returned unprocessed. Sources: NC OSFM page and 24 CFR 3282.203(d), both above.
2. Missing the required checklist, index or page numbers. North Carolina lists a missing completed QC Manual Checklist and unindexed or unnumbered pages as deficiency causes. ICC/MBI 1205 §501.1 independently requires an indexed booklet. A manual the reviewer cannot navigate to find §501.13 is a manual that gets sent back.
3. Missing the third-party agency's certification letter or contract. North Carolina requires the third-party to review and stamp the manual first. Montana's application makes the third-party inspector a required field. A manual submitted without an agency behind it is not reviewable.
4. Thin job descriptions for the quality role. North Carolina calls out inadequate QC inspector job descriptions. ICC/MBI 1200 §504.1 requires the responsible party to have "the authority necessary to ensure compliance" and to demonstrate knowledge and ability to the inspection agency. A chart with a name and no authority statement fails that.
5. Inspection sections with no accept/reject criteria and no frequency. ICC/MBI 1205 §501.7 requires accept/reject criteria, mandatory inspection characteristics, frequency, and how nonconformances are remedied, all in one section. Manuals that say "the inspector checks the panel" satisfy none of the four. Inference from the requirement, not a published statistic.
6. No sign-offs. §501.8 asks for the inspection list per station and sign-offs; HUD asks for identification by title of each person accountable for each inspection. A checklist with no name on it is the most common thing a small plant produces.
7. Forms referenced but not attached. §501.17 requires the forms themselves plus a written procedure for each; AC157 §4.3.11 requires an example of each form and report. Inference from the requirement.
8. Retention period not stated. §501.12 explicitly requires the manual to identify how long records are kept. It is one sentence and it is easy to omit.

Losing approval or being stopped after approval:

9. Failing the initial factory inspection. Under HUD the in-plant agency performs an initial factory inspection and issues a deviation report; labels do not come until the deviations are corrected and the certification report is signed (24 CFR 3282.204(b), (c)). Montana's third-party agency plays the equivalent role. A manual approved on paper does not produce a single insignia until a person confirms the plant matches it.
10. Not following the approved manual in production. Under 24 CFR 3282.362 the in-plant agency is responsible for assuring the plant is capable of following the manual, that it continues to follow it, and it has red-tag authority when product does not conform. Source: https://www.ecfr.gov/current/title-24/subtitle-B/chapter-XX/part-3282/subpart-H/section-3282.362 (title and content seen via search, 13 Sep 2026; eCFR blocks automated fetching, so the section text is NOT CONFIRMED verbatim).
11. Making a change without getting the change approved. 24 CFR 3282.203(e) requires the approving agency's approval of a manual change before production for sale. ARM 24.301.1223(3) requires the revised manual to go to the bureau with the fee. Changing the process and not the manual is the classic way a compliant plant drifts out of compliance.
12. No current copy in the plant. ICC/MBI 1200 §503.2 requires a printed copy of the approved plan available for unannounced inspection; 24 CFR 3282.203(g) requires a current, readily accessible copy in each plant.
13. Restricting access. ICC/MBI 1200 §505.1 and 1205 §501.3: the plant cannot restrict the AHJ or the agency, and the manual itself must carry the signed permission. Turning an inspector away once is a direct violation of a clause in your own manual.
14. Insignia problems. ARM 24.301.1243: insignia are issued against a model number and specific serial numbers and expire 12 months after issuance with no refund. Poor label control is both a money leak and a findable violation.
15. Records that do not exist when asked for. ICC/MBI 1200 §504.3.2 and §504.3.3: all documentation available to the AHJ on request and retained not less than 12 months after delivery. AC157 §4.5.12 sets two years for a concrete fabricator. The record that does not exist is indistinguishable from the inspection that never happened.

7. Recommended structure for Ken's plant#

Sized for a plant where the same few people do several jobs. Numbered so a reviewer can find any requirement fast, and cross-referenced to ICC/MBI 1205 so the bureau can tick its list. Target length for a first submission is 40 to 70 pages including the forms, not 300.

Front matter
  Cover: "Compliance Assurance Program"  [1205 §501.1]
    manufacturer name and address, plant address,
    third-party inspection agency, evaluation agency if any
  Table of contents, indexed, every page numbered "MT-QAM Rev _ , page _ of _"
  Revision history table
  Cross-reference table: ICC/MBI 1205 Ch. 5 section -> this manual's section
  Signed permission to inspect without prior announcement  [§501.3]

1. Scope, products and codes
  1.1 Purpose and scope of this manual  [MT list item 1]
  1.2 Products covered: wall, roof and floor panels; the shower house on a steel skid
  1.3 Codes and standards this plant builds to
  1.4 Definitions

2. The quality program and the organisation
  2.1 Quality policy statement  [AC157 §4.4.1]
  2.2 Organisation chart  [§501.4]
  2.3 Roles, authority and independence: who may stop work, who may reject,
      who signs a release, and who that person reports to  [1200 §504.1]
  2.4 Job descriptions by title
  2.5 Personnel qualifications by role
  2.6 Training and training records  [§501.9]
  2.7 Internal audit  [§501.10]
  2.8 Annual management review  [AC157 §4.4.2]
  2.9 Corrective and preventive action, the POCA procedure  [§501.10]

3. Documents and drawings
  3.1 How an approved plan reaches the floor  [§501.11]
  3.2 Revision control and withdrawal of superseded documents
  3.3 Conformance of construction documents to the approved building system
  3.4 Revision of this manual and resubmission to the bureau  [§501.2, ARM 24.301.1223(3)]

4. The plant
  4.1 Plant layout with stations and testing stations  [§501.5]
  4.2 Major production equipment, keyed to the layout  [MT list item 8]
  4.3 Station-by-station description of the work  [§501.6]

5. Purchasing and materials
  5.1 Purchasing and specification of purchased product
  5.2 Approved vendors and testing agencies
  5.3 Incoming inspection at receipt and at point of use  [§502.1]
  5.4 Material certifications on file
  5.5 Storage, protection and stock rotation  [§502.2, MT list item 3]
  5.6 Rejected materials: segregation and disposal  [§502.3]

6. Concrete control  (the section a modular manual does not have)
  6.1 Mix designs and their approval
  6.2 Mix qualification and the triggers for requalification
  6.3 Batching: proportioning, metering, and calibration of scales, water meter
      and foam nozzle  [ACI 523.1R §5.2]
  6.4 Mixing and uniformity  [ACI 523.1R §5.3]
  6.5 Cast density at the point of placement: method, frequency, acceptance band
      [ACI 523.1R §4.3, §5.3]
  6.6 Cylinder sampling, curing of specimens, break ages and results
      [ACI 523.1R §4.3; ASTM C495]
  6.7 Placing and consolidation; the cavity fill pour
  6.8 Curing the product and curing the specimens; the 7 day release rule
  6.9 Cold and hot weather  [ACI 523.1R §5.7, §5.8]
  6.10 Low breaks and out-of-band density: what happens next

7. Fabrication and in-process inspection
  7.1 The panel traveler and how it moves with the panel
  7.2 Bed and form control, pre-pour bed check
  7.3 Steel: studs, track, channel rows, screw patterns
  7.4 Mesh placement and laps
  7.5 Embedments: sleeves, blockouts, openings
  7.6 Lifting inserts: type, depth, position  (HOLD POINT)
  7.7 Pre-pour inspection and sign-off  (HOLD POINT)
  7.8 Strip, handling and the post-strip dimensional check
  7.9 Dimensional tolerances and surface defect acceptance criteria
  7.10 Shower house assembly: skid, floor panel, walls, partition, roof
  7.11 MEP rough-in inspection before the cavity fill  (HOLD POINT)
  7.12 Inspection points table: characteristic, criteria, frequency, form, signer
       [§501.7, §501.8]

8. In-plant testing
  8.1 Test procedural manual: electrical  [MT list item 10]
  8.2 Test procedural manual: gas line
  8.3 Test procedural manual: water system
  8.4 Test procedural manual: DWV and fixtures
  8.5 Concrete tests performed in plant
  8.6 List of test equipment  [MT list item 11]
  8.7 Calibration and maintenance schedule, traceability  [§501.14]

9. Nonconformance
  9.1 Identifying and marking nonconforming product
  9.2 Disposition: use as is, rework, repair, scrap, and who signs
  9.3 Feeding a nonconformance into corrective action

10. Identification, traceability and labels
  10.1 Serial numbering system  [§501.13]
  10.2 Traceability: unit to materials, to QC personnel, to plans, to records
  10.3 Insignia control: ordering, storage, security, assignment, month-end
       reporting, void and unused insignia  [§503.1, ARM 24.301.1243]

11. Final inspection and release
  11.1 Final inspection procedure  [§503.2]
  11.2 Identification and labeling
  11.3 Release authority and the release record

12. Storage, packaging, handling and transport
  12.1 Storage at the plant, at other storage points, and on site  [§501.15]
  12.2 Stacking limits and weather protection  [1200 §605]
  12.3 Packaging and protection  [§501.16]
  12.4 Loading and unloading manifest  [1200 §704.1]
  12.5 Transport, lifting and placement instructions issued with each set
       [1200 §701.1]

13. On-site set instructions
  13.1 Foundation or skid interface and anchorage  [1200 §802, §804.1(5)]
  13.2 Panel-to-panel and module-to-module connections  [1200 §804.1(1)]
  13.3 Envelope continuity at joints  [1200 §804.1(2)]
  13.4 Services and MEP connections  [1200 §804.1(3), (7)]
  13.5 Installation tolerances  [1200 §803.1]
  13.6 What is completed on site  [1200 §804.1(8)]

14. Records
  14.1 Records list, location and access  [§501.12]
  14.2 Retention periods  [§501.12, 1200 §504.3.3]
  14.3 Notification duties: before fabrication, plant closure, major variations
       [1200 §505.2, AC157 §4.4]

15. Owner information, warranty and service
  15.1 What goes to the owner with the building
  15.2 Warranty
  15.3 Complaints, field service and how they feed corrective action
       (good practice; NOT confirmed as a Montana requirement)

Appendix A  Forms, each with its written procedure of use  [§501.17]
Appendix B  Plant layout drawing
Appendix C  Equipment and test equipment lists
Appendix D  Approved vendor list
Appendix E  Approved mix designs
Appendix F  Personnel qualifications and training records index

Which sections can start thin and grow.

Start thin, and say in the manual that they are scaled to current volume:

• 2.7 internal audit and 2.8 management review: one audit per quarter and one review per year is a defensible starting point for a plant running a handful of units. State the frequency; do not promise monthly audits you will not do.
• 5.1 purchasing and 5.2 approved vendors: with three or four suppliers this is a one-page procedure and a one-page list.
• 15 owner information and warranty: a page each until a customer contract forces more.
• 12.1 storage: if units ship straight off the yard, say so, and say what changes if they ever stack.

Start fat and never thin, because these are what get inspected:

• 6 concrete control, in full, from day one. It is the section no other modular manual has and the one with the least published backup, so it has to be self-sufficient.
• 7.12 the inspection points table with criteria, frequency and named signer. This is the heart of the manual and the single most common weak spot.
• 8 in-plant testing, because Montana names it explicitly and by trade.
• 10 identification and labels, because insignia are money and expire.
• 14 records, because a stated retention period is a one-sentence requirement that is easy to fail.

Write section 3.4 so that ordinary changes (a new vendor, a new form revision, a new model) update an appendix rather than the body of the manual. Appendices can be revised with a lighter touch. Every change to the body triggers ARM 24.301.1223(3), which means a fee and a re-review, which means a delay on whatever plan review is in flight at the time.

8. What must be true in the plant before this manual can honestly be submitted#

An approved manual describes a system that operates. Some of these are gates, and some are just honesty.

Hard gates, the manual is not truthful without them:

1. A plant exists, with a fixed layout and named stations. §501.5 and §501.6 require a schematic with stations and testing stations and a detailed list of the work at each one. You cannot describe stations on a floor that has not been laid out.
2. A third-party inspection agency is under contract, chosen from the bureau's approved list. Montana's application makes it a required field, and 1200 §504.1 requires quality personnel to demonstrate their competence to the inspection agency. Pick the agency before drafting; they will tell you the format they want, and in some states they review the manual before the state does.
3. A named person owns quality, with real authority and enough independence to stop a release that production wants to ship. 1200 §504.1. In a small plant this is the hardest structural requirement, because the person who casts the panel cannot be the sole person who accepts it.
4. The approved plans exist. Section 3 of the manual describes how an approved plan reaches the floor. The manual is a gate on plan review under ARM 24.301.1223(1), so the two run together, but the design has to be far enough along that the drawing set, the revision scheme and the bill of material are real.
5. Mix designs are qualified, not assumed. §4.5.6.2 of AC157 requires the mix to be verified before use with representative batching, equipment, methods and curing. Today standards-register.md says the strength at 35 pcf is unknown until C495 cylinders exist. A manual with a mix design section and no qualification data behind it is describing a system that is not operating. The test-matrix.md "Now" items (C796 agent qualification, C495 at 7 and 28 days, C138 and C567 density, C157 shrinkage) are the prerequisite, and they run on lab lead time, not on Ken's schedule.
6. Accept/reject criteria exist and are stamped. §501.7. Panel dimensional tolerances and surface defect acceptance have no published source for this product (sections 4.8 and 4.9 above). They have to be written by Ken and accepted by the PE before the manual can state them.
7. Batching and measuring equipment is on site and calibrated, with traceable records. ACI 523.1R §5.2 says every batching device is calibrated before starting; §501.14 and AC157 §4.5.8.1 want the schedule and the traceability. Scales, water meter, foam nozzle, thermometers and the tape measures used for the dimensional check all count.
8. The test equipment named in section 8 is bought and the people can use it. Montana names electrical, gas line, water and DWV tests explicitly. These are the tests the bureau's own list singles out, which means they are the tests it expects to see.
9. The forms exist as blank forms. §501.17 and AC157 §4.3.11 require the forms and the procedure for each, in the manual. The forms are part of the submission, not a follow-on.
10. The set instructions exist, at least for the first model. 1200 §804.1 and §803.1 put connection details, anchorage, envelope continuity and installation tolerances on the manufacturer and the PE. Open items in wall-spec-v1.md §4 (joint screw pattern, slab anchor, base detail, window and door anchoring) have to close before the set instructions are writable.

Things that should be true but can be stated as a plan:

11. People are trained. §501.9. Training records can start with the first entries; the procedure is what is being approved.
12. One trial run has happened. Not required by any rule I found, but the fastest way to find out whether the station descriptions and the traveler actually work is to cast one bed and push one panel through every form. Do it before submission, and the deviation report from the initial factory inspection gets much shorter.
13. The insignia process has been walked through once on paper, so the serial numbers on the panel traveler, the serial numbers on the insignia application and the numbers in the label control log all match. ARM 24.301.1243 ties them together and the 12 month expiry punishes getting it wrong.

The honest summary: the manual is writable today in every section except concrete acceptance criteria and mix qualification, and those two are gated on the lab work already listed as "Now" priority in test-matrix.md. Start the lab work first. The manual is a four to six week drafting job; the 28 day breaks and the shrinkage prisms are not compressible.

9. Sources#

All fetched 13 Sep 2026.

Montana

• ARM 24.301.1223, in-plant quality assurance manual: https://www.law.cornell.edu/regulations/montana/Mont-Admin-r-24.301.1223
• ARM 24.301.1203, incorporation of ICC/MBI 1200-2021 and 1205-2021: https://www.law.cornell.edu/regulations/montana/Mont-Admin-r-24.301.1203
• ARM 24.301.1201, applicability and adopted codes: https://www.law.cornell.edu/regulations/montana/Mont-Admin-r-24.301.1201
• ARM 24.301.1243, application for insignia: https://www.law.cornell.edu/regulations/montana/Mont-Admin-r-24.301.1243
• ARM 24.301.1261, review fees including the $20 quality control manual review: https://www.law.cornell.edu/regulations/montana/Mont-Admin-r-24.301.1261
• Building Codes Bureau, Factory-Built Buildings page (the QC manual content list, approved third-party agencies, forms): https://bsd.dli.mt.gov/building-codes-permits/permit-applications/factory-built-buildings/
• Application for approval of factory built building (Rev. 4/23): https://bsd.dli.mt.gov/building-codes-permits/permit-applications/factory-built-buildings/FBBP_APPLICATION_ADOBE_F.pdf
• Insignia application: https://bsd.dli.mt.gov/building-codes-permits/permit-applications/factory-built-buildings/FBBP_INSIGNIA_APP_ADOBE_F.pdf
• Third party inspector certification form: https://bsd.dli.mt.gov/building-codes-permits/permit-applications/factory-built-buildings/3rdPartyInspCertApp.pdf
• MCA 50-60-402, factory-built buildings to comply with standards: https://mca.legmt.gov/bills/mca/title_0500/chapter_0600/part_0040/section_0020/0500-0600-0040-0020.html

ICC/MBI

• ICC/MBI 1205 approved draft ballot PDF (source of the Chapter 5 section text used here): https://www.iccsafe.org/wp-content/uploads/is_osmc/ICC1205-draft-ballot-apprvd.pdf
• ICC/MBI 1200 approved draft ballot PDF: https://www.iccsafe.org/wp-content/uploads/is_osmc/ICC1200-draft-ballot-apprvd.pdf
• Published 1205-2021 on ICC Digital Codes (blocks automated fetching; used only to corroborate section numbering): https://codes.iccsafe.org/content/ICC12052021P1/chapter-5-requirements-for-compliance-assurance-programs
• Published 1200-2021 Chapter 5 on ICC Digital Codes: https://codes.iccsafe.org/content/ICC12002021P1/chapter-5-manufacturing-plant
• 2025 collected volume including 1210-2023: https://codes.iccsafe.org/content/ICCMBIOSCS2023P1
• NEEP explainer on 1200 and 1205: https://neep.org/sites/default/files/media-files/iccmbi_1205.pdf

HUD

• 24 CFR 3282.203, DAPIA services, verbatim from the 4-1-24 CFR: https://www.govinfo.gov/content/pkg/CFR-2024-title24-vol5/pdf/CFR-2024-title24-vol5-sec3282-203.pdf
• 24 CFR 3282.203 (cross-check): https://www.law.cornell.edu/cfr/text/24/3282.203
• 24 CFR 3282.204, IPIA services: https://www.law.cornell.edu/cfr/text/24/3282.204
• 24 CFR 3282.362, production inspection primary inspection agencies (text NOT CONFIRMED verbatim, eCFR blocks fetching): https://www.ecfr.gov/current/title-24/subtitle-B/chapter-XX/part-3282/subpart-H/section-3282.362

IAS

• AC157, fabricator inspection programs for reinforced and precast/prestressed concrete, June 2024 ed., editorially revised Aug 2025: https://www.iasonline.org/wp-content/uploads/2025/09/AC157-Final-June-2024-ed20250820.pdf
• IAS inspection agency accreditation, AC98 and ISO/IEC 17020: https://www.iasonline.org/services/inspection-agencies/
• PCI and IAS AC157 cooperation: https://www.pci.org/PCI/PCI/PCI-Certification/Plant_Certification/IAS-AC157.aspx
• AC291, special inspection agencies (context only): https://cdn-v2.iasonline.org/wp-content/uploads/2023/11/AC291-Final.pdf

Concrete

• ACI 523.1R-06, Guide for Cast-in-Place Low-Density Cellular Concrete, abstract: https://www.concrete.org/publications/internationalconcreteabstractsportal.aspx?m=details&id=18403
• ACI 523.1R-06 full text (licensed copy hosted by the University of Utah; buy the ACI copy before citing in a submission): https://my.civil.utah.edu/~bartlett/LCC/misc/523.1r-06-guide-for-cast-in-place-low-density-cellular-concrete.pdf
• ACI 523.2R-96 / ACI PRC-523.2-96, Guide for Precast Cellular Concrete Floor, Roof, and Wall Units, abstract: https://www.concrete.org/publications/internationalconcreteabstractsportal.aspx?m=details&ID=5227
• PCI MNL-116-21, QC Manual for Structural Precast Products (division titles NOT CONFIRMED): https://www.pci.org/PCI/PCI/Bookstore/Item_Detail.aspx?iProductCode=MNL-116-21&Category=QA

Comparator state programs

• North Carolina OSFM, modular manufacturer approval procedures (QC manual contents, deficiency causes, $500 re-review fee): https://www.ncosfm.gov/manufactured-bldg/modular-buildings/modular-manufacturer-approval-procedures

10. Open items, and what is not confirmed#

1. Buy ICC/MBI 1205-2021 and verify Chapter 5 section numbering against the approved draft ballot text used here. Everything in section 3 of this document hangs on those section numbers.
2. Buy ICC/MBI 1200-2021 as well; Montana adopts it and its Chapters 5 through 8 shape the manual.
3. Ask the bureau whether it has an internal QC manual checklist or preferred format. Phone (406) 841-2056, buildingcodes@mt.gov. Free, and it would settle several questions in one call.
4. Buy ACI 523.2R-96 (ACI PRC-523.2-96). It is the only published document specifically about precast cellular concrete floor, roof and wall units at this density, and its fabrication and handling content is not yet read.
5. Buy PCI MNL-116-21 or confirm its division titles before using it as a skeleton.
6. Panel dimensional tolerances: no published source for this product. PE to set. Add to the PE package.
7. Surface and defect acceptance criteria: no published source. Ken to draft with photographs, PE and third-party agency to accept.
8. Owner or consumer manual and warranty: not confirmed as a Montana requirement for factory-built buildings. Include as good practice, ask the bureau.
9. 24 CFR 3282.362 text: not read verbatim (eCFR blocks automated fetching). The characterisation of the in-plant agency's continuing duty and red-tag authority comes from search-result summaries, and it is analogue material anyway, not Montana law.
10. Whether the third-party agency reviews the manual before the bureau does, as in North Carolina, or whether the bureau reviews it directly. ARM 24.301.1223(2) says the bureau reviews and approves it. The agency's role in that sequence is worth confirming with the agency Ken picks.