1 Scope
NOTE This standard covers the furnishing and installation of interior architectural wood trim, wood paneling, wood ceiling and wall slat systems, and ornamental woodwork for commercial, institutional, hospitality, and similar buildings. (1.1)
NOTE The work under this standard is the architectural woodwork that finishes the surfaces of a room rather than the cabinetry that occupies it: the standing and running trim that frames openings and bands the walls; the flat-panel, raised-panel, and stile-and-rail wall paneling that clads them; the linear slat and plank systems applied to walls and ceilings; the applied moldings, pilasters, columns, and ornamental members that articulate them; and the transparent or opaque finish that the woodwork carries. (1.2)
NOTE The scope includes the architectural-woodwork quality grade, the lumber species and grade, the veneer species, cut, and matching, the panel product and core, the fire-retardant treatment where the woodwork is regulated as an interior finish, the finish system and whether it is applied in the shop or in the field, the moisture content and acclimatization, the concealed blocking and hanging systems, the expansion and movement provisions, and the field installation. (1.3)
NOTE As with casework, the single most consequential decision in this standard is the quality grade — the AWS published jointly by AWI, AWMAC, and WI, and the successor ANSI/AWI product standards (ANSI/AWI 0622.0646 for millwork and wood trim and ANSI/AWI 0642 for wood paneling) define three aesthetic grades (Economy, Custom, and Premium) that propagate into the species and cut allowed, the number and visibility of joints in a run of trim, the veneer match and panel sequencing across a wall, the allowable warp and flatness of a panel, the joinery, and the finish quality, so specifying the grade incorrectly either over-builds the woodwork at needless cost or under-builds it so it fails to meet the project's appearance expectations. (1.5)
NOTE This standard establishes the grade, material, matching, fire-rating, finish, and installation requirements for the woodwork shown on the project drawings. (1.6.1)
1.6.5Coordinate this work with Interior Painting where opaque-finished woodwork is field-finished by the painting trade. 1.6.7Coordinate this work with Firestopping where paneling conceals a rated assembly or a penetration. 2 Referenced Standards
2.1 Compliance with Referenced Standards
2.1.1Materials, fabrication, and installation shall comply with the latest adopted editions of the referenced standards listed below.
2.1.2Where the contract documents or the adopted building code impose more stringent requirements than a referenced standard, the more stringent requirement shall govern.
2.1.3The Contractor shall resolve conflicts in writing with the Architect before fabrication begins.
2.2 Reference List
| Standard |
Title |
| AWI/AWMAC/WI AWS |
Architectural Woodwork Standards (quality grades and general requirements) |
| ANSI/AWI 0622.0646 |
Millwork & Wood Trim (standing and running trim, moldings, ornamental woodwork) |
| ANSI/AWI 0642 |
Wood Paneling (flat-panel, raised-panel, stile-and-rail, and slat systems) |
| ANSI/AWI 0620 |
Finish Carpentry / Installation (installation grade requirements) |
| ANSI/HPVA HP-1 |
Standard for Hardwood and Decorative Plywood (veneer grades and matching) |
| ANSI A208.1 |
Particleboard |
| ANSI A208.2 |
Medium-Density Fiberboard (MDF) for Interior Applications |
| NEMA LD 3 |
High-Pressure Decorative Laminates (where trim or paneling is laminate-faced) |
| ASTM E84 |
Surface Burning Characteristics of Building Materials (flame spread / smoke developed) |
| UL 723 |
Test for Surface Burning Characteristics of Building Materials (equivalent to ASTM E84) |
| AWPA U1 |
Use Category System: User Specification for Treated Wood (fire-retardant treatment, Category UCFA interior) |
| ASTM D5116 |
Small-Scale Environmental Chamber Determination of Organic Emissions from Indoor Materials/Products |
| EPA 40 CFR Part 770 |
Formaldehyde Emission Standards for Composite Wood Products (TSCA Title VI) |
| CARB ATCM 93120 |
Airborne Toxic Control Measure — Composite Wood Products (Phase 2) |
| IBC |
International Building Code (interior wall and ceiling finish classification) |
3 Submittals
3.1 Action Submittals
3.1.1The following submittals shall be submitted for review and returned before fabrication begins.
3.1.2Submittals shall be complete and internally coordinated before any item is submitted, and shall identify the AWS / ANSI/AWI quality grade for each category of work.
- Product Data: Manufacturer's product data for each lumber species and grade, veneer species and cut, panel product and core, adhesive, fastener, fire-retardant treatment, and finish system, including thickness, composition, performance ratings, and the applicable formaldehyde-emission and fire-test documentation.
- Shop Drawings: Plans, interior elevations, reflected ceiling plans, and large-scale sections and profile details of each trim run, paneling elevation, and slat system, drawn to scale, showing profiles, dimensions, joint locations and types, panel and slat module, reveal and shadow-line dimensions, the relationship to adjacent openings and finishes, concealed blocking and backing requirements, the hanging or attachment method, expansion-and-movement provisions, and fastener locations and concealment.
- Veneer Layout and Sequence: For transparent-finished wood-veneer paneling, a veneer layout (elevation) drawing showing the leaf-to-leaf match within each panel face, the panel-to-panel assembly match across each wall elevation, and the sequencing of sequence-matched and blueprint-matched panels in the order they are to be installed. Where the project requires it, a flitch submittal or a sample blanket from the actual flitch shall be provided for the Architect's selection and approval before the veneer is laid up.
- Samples: Finish samples of each species, cut, and finish system on the actual substrate, showing color, sheen, and grain; a sample of each trim profile in the specified species; a corner or joint sample at Custom and Premium grade; and, for fire-retardant-treated work, a sample carrying the treater's classification label.
- Quality Grade Certification: Documentation of the AWS / ANSI/AWI grade certification for the trim and paneling, including AWI Quality Certification Program (QCP) certification or equivalent third-party certification where required by the contract documents.
- Fire-Test and Treatment Reports: Where the woodwork is regulated as an interior wall or ceiling finish, the ASTM E84 (or UL 723) test report establishing the flame-spread and smoke-developed classification of the assembly as it will be installed (including the effect of the finish), and, where fire-retardant-treated wood is used, the AWPA U1 treatment record and the treater's classification label.
- Formaldehyde Compliance: TSCA Title VI / CARB Phase 2 compliance documentation for all composite-wood panel components, including labeling or certificates of conformity.
☐ Product data for lumber, veneer, panel, core, adhesive, fastener, treatment, and finish
☐ Dimensioned shop drawings, elevations, RCPs, and large-scale profile sections
☐ Veneer layout / sequence drawing (transparent-finished veneer paneling)
☐ Flitch / sample-blanket submittal for veneer selection (where required)
☐ Finish, profile, and joint samples on actual substrate
☐ AWS / ANSI/AWI quality grade certification (AWI QCP or equivalent)
☐ ASTM E84 fire-test report and AWPA U1 treatment record (where regulated as finish)
☐ Formaldehyde compliance documentation (TSCA Title VI / CARB Phase 2)
3.2 Closeout Submittals
3.2.1At substantial completion the Contractor shall provide the following for the Owner's future repairs:
- Finish-specific care and maintenance instructions for each finish and species
- Manufacturer's written warranty
- Attic-stock matching trim lengths, panel blanks, and touch-up finish
☐ Finish-specific care and maintenance instructions
☐ Manufacturer and installation warranty documentation
☐ Attic-stock matching trim, panel blanks, and touch-up finish
3.2.2Care instructions are finish-specific; the Owner's housekeeping staff shall be given the correct guidance to avoid finish damage.
NOTE A transparent catalyzed finish, a field-applied oil finish, and an opaque painted finish each tolerate different cleaning chemistries, so the care guidance must be matched to the finish on each surface. (3.2.2.1)
4 Quality Assurance
4.1 Manufacturer Qualifications
○ AWI Quality Certification Program (QCP) certified
○ Equivalent third-party woodwork certification program
○ Manufacturer's self-certification of grade compliance (where AHJ/Architect accepts)
4.1.1The woodwork manufacturer shall be a firm regularly engaged in the fabrication of architectural trim and paneling of the type, grade, species, and finish specified, with documented experience on comparable projects.
4.1.2Where the contract documents require third-party grade certification, the manufacturer shall be a licensed participant in the AWI Quality Certification Program (QCP) or an equivalent program.
4.1.3Where third-party grade certification is required, the woodwork shall bear the program's certification label.
4.2 Single-Source Responsibility
○ All trim, paneling, and ornamental woodwork of a species from a single manufacturer
○ Coordinated package from a single supplier with documented material sourcing
4.2.1All trim, paneling, and ornamental woodwork within a related scope and species shall be furnished by a single manufacturer so that grade, species, cut, veneer match, and finish are consistent across the work.
NOTE Wood color and figure vary between trees, flitches, and mills, so woodwork drawn from a single coordinated source and, for veneer, from sequenced flitches is the only way to hold a uniform appearance across a room or a building. (4.2.1.1)
4.3 Mockup
NOTE A mockup is typically a panel module showing the leaf and assembly match, the trim profile and a joint, the reveal or shadow line, and the specified finish. (4.3.1)
○ Yes — provide one representative paneling and trim mockup for approval
○ No — mockup not required
4.3.2Where required by the contract documents, the Contractor shall provide a full-size mockup of a representative paneled wall or trim assembly for the Architect's review and approval of grade, species, match, profile, and finish.
4.3.3The approved mockup shall establish the standard of quality for the work and may be incorporated into the finished work if undamaged and in an approved location.
4.4 Grade Compliance
4.4.1The trim and paneling shall comply in all respects with the requirements of the specified AWS / ANSI/AWI grade for material, joinery, matching, flatness, and finish.
4.4.2The specified grade shall govern wherever this standard is silent.
4.4.3Where this standard establishes a requirement more stringent than the grade minimum, this standard shall govern.
5 Environmental and Service Conditions
5.1 HVAC Operational Before Delivery
○ Permanent HVAC operating and interior conditioned; wet work complete and dry; building enclosed (standard)
○ Temporary conditioning maintaining the service humidity range (where permanent HVAC is not yet available)
5.1.1Wood trim and paneling shall not be delivered to the building until wet-work (concrete, masonry, plaster, and gypsum finishing) is complete and dry, the building is enclosed and weather-tight, and the permanent HVAC system is operating and maintaining the interior temperature and humidity within the range the woodwork will experience in service.
NOTE Wood is hygroscopic — it continuously gains and loses moisture with the surrounding air until it reaches equilibrium — so woodwork installed before the building's permanent conditions are established will shrink, swell, cup, or open at its joints once those conditions are reached, a failure that no quality of fabrication can prevent. (5.1.1.1)
5.2 Interior Humidity and Moisture Content
2555
253035455055
Default: 45 % RH
5.2.1The interior relative humidity at delivery and in service shall be maintained within the range the AWS specifies for the geographic region and season, generally between 25% and 55% RH, with extended swings avoided.
5.2.2Wood moisture content at the time of fabrication and installation shall be in equilibrium with that service condition.
5.2.3Architectural woodwork shall be fabricated and delivered at a moisture content near 6% to 9% rather than at the higher moisture content of construction-grade lumber.
NOTE For most interior conditioned spaces in North America a 25% to 55% RH service range corresponds to an equilibrium moisture content near 6% to 9%, so woodwork installed wetter than its service equilibrium will shrink and open its joints while woodwork installed drier than its service equilibrium will swell and buckle a paneled wall. (5.2.3.1)
5.3 Acclimatization
24168
24487296168
Default: 72 hours
5.3.1Trim and paneling shall be delivered to the conditioned space and acclimatized before installation so that the woodwork reaches equilibrium with the interior conditions while it is still loose and able to move freely, rather than after it is fixed to the wall.
5.3.2The Contractor shall protect the woodwork during acclimatization, stack it so air circulates around each piece, and not begin installation until the woodwork has stabilized at the service condition.
6 Quality Grade
NOTE The quality grade is the governing decision for the standard. (6.1)
○ Economy — utility and back-of-house woodwork
○ Custom — standard commercial and institutional default
○ Premium — high-visibility architectural feature woodwork
6.2 Grade Selection Guidance
NOTE Custom grade is the commercial default and is appropriate for the large majority of commercial and institutional trim and paneling: it provides sound joinery, good appearance, controlled veneer matching, and a durable finish at a reasonable cost. (6.2.1)
NOTE Economy grade is suitable only for utility and back-of-house work — service corridors, storage, and concealed locations — where appearance is not a priority. (6.2.2)
NOTE Premium grade is reserved for the most visible, architecturally significant woodwork — lobbies, boardrooms, courtrooms, executive suites, and feature walls — where the tightest tolerances, the best veneer selection and matching, the most exacting joinery, and the highest finish quality are required and the budget supports them. (6.2.3)
6.3 Grade by Area
NOTE It is common and economical to specify Premium grade for the public and high-visibility woodwork shown on the drawings and Custom grade for the balance. (6.3.1)
6.3.2The grade may be set differently for different areas of a project.
6.3.3The shop drawings and finish schedule shall make clear which grade governs each location.
7 Materials
7.1 Lumber Species and Grade
Red oak
White oak
Hard maple
Cherry
Walnut
Mahogany / sapele
Other species per finish schedule
○ Paint-grade close-grain hardwood (e.g., poplar) for trim and flat members
○ MDF for profiled and molded members (smooth, stable, knot-free paint substrate)
○ Finger-jointed paint-grade lumber for long running trim (concealed by paint)
7.1.1Solid-lumber trim, stiles, rails, and ornamental members shall be of the species, cut, and grade scheduled, and shall meet the appearance and defect requirements of the specified AWS / ANSI/AWI grade for the chosen finish.
NOTE The species governs color, hardness, grain figure, cost, and whether the woodwork is intended for a transparent finish (a species selected for its figure and color such as oak, maple, cherry, or walnut, with its grain exposed) or an opaque finish (a close-grained paintable species such as poplar, a paint-grade hardwood, or MDF for profiled members, because the paint hides the grain and a less expensive paint-grade species is appropriate). (7.1.1.1)
7.2 Lumber Cut
NOTE The cut of the lumber and veneer — how the log is sawn relative to the growth rings — determines the grain pattern that shows on the face and how the wood moves with changes in moisture. (7.2.1)
Plain-sawn / flat-sawn — cathedral grain, economical (standard)
Quarter-sawn — straight grain, ray fleck in oak, more stable
Rift-sawn — tight uniform straight grain, no fleck (most refined)
Mixed / as selected per location on finish schedule
NOTE Plain-sawn (flat-sawn) lumber shows the familiar cathedral or "flame" grain, is the most economical and highest-yield cut, and is the default for most trim and paneling. (7.2.2)
NOTE Quarter-sawn lumber, cut radially, shows a straight, vertical grain (and, in oak, the prized ray fleck), is more dimensionally stable across its width, and is selected where a straight-grain appearance or maximum stability is wanted. (7.2.3)
NOTE Rift-sawn lumber, cut at an angle between plain and quarter, shows a very straight, tight, uniform grain with no flecking and is the most material-intensive and costly cut, used for the most refined straight-grain work. (7.2.4)
7.3 Veneer for Transparent-Finished Paneling
○ ANSI/HPVA HP-1 decorative veneer at the specified AWS grade (standard)
○ Architect-selected flitch, sequenced and reserved for the project (Premium feature work)
7.3.1Transparent-finished wood paneling shall use a decorative wood veneer conforming to ANSI/HPVA HP-1, of the species and cut scheduled, laid up over the specified panel core.
7.3.2The veneer grade, species, and cut shall meet the requirements of the specified AWS / ANSI/AWI grade.
NOTE Veneer paneling is preferred to solid-wood paneling for almost all flat and stile-and-rail paneling because a veneered panel is dimensionally stable and flat where a wide solid-wood panel would cup and split, because a single flitch yields enough matched veneer to clad a wall in one continuous figure, and because the figured and exotic species used for feature walls are available only as veneer. (7.3.2.1)
7.4 Veneer Leaf Matching
NOTE Within a single panel face, the individual veneer leaves are matched to one another to set the figure. (7.4.1)
○ Book match — adjacent leaves mirrored, maximum grain continuity (standard)
○ Slip match — leaves slid without flipping, repeating figure (ribbon-stripe veneers)
○ Random / plank match — mixed leaves, deliberately non-uniform planked look
NOTE Book match — turning every other leaf over so adjacent leaves mirror each other at the joint like the open pages of a book — is the standard and most widely used match, giving maximum grain continuity across the joints and a symmetrical figure. (7.4.2)
NOTE Slip match — sliding successive leaves out without flipping them, so the same face of each leaf shows and the figure repeats without mirroring — is used to avoid the barber-pole effect that book matching can produce in certain ribbon-stripe veneers and to give a more uniform, repeating pattern. (7.4.3)
NOTE Random (plank) match — placing leaves without regard to grain continuity, deliberately mixing color and figure — gives a casual, planked, unmatched appearance and is used where a non-uniform, board-like look is the design intent. (7.4.4)
7.5 Veneer Panel-Face Assembly Match
NOTE Separately from how leaves are matched to one another, the leaves are arranged on the panel face to set its symmetry. (7.5.1)
○ Running match — non-uniform, most economical (concealed or back-of-house)
○ Balance match — equal-width leaves, symmetrical face (Custom default)
○ Center-balance match — centered grain joint, most refined (Premium feature work)
NOTE Running match assembles each face from as many leaves as the width requires, with no attempt to make the leaves equal in width or symmetrical, so panel faces are not uniform from one to the next; it is the most economical assembly and is used where panels are not seen side by side. (7.5.2)
NOTE Balance match uses leaves of an equal width on each face so the face is symmetrical (an even or odd number of equal leaves), giving a consistent, balanced appearance across panels. (7.5.3)
NOTE Center-balance match uses an even number of equal-width leaves with a single grain joint centered on the panel face; it is the most symmetrical and refined assembly, the most labor- and material-intensive, and the default for the most visible Premium work. (7.5.4)
7.6 Panel-to-Panel Sequence Matching
NOTE Across a wall elevation, the finished panels are matched to one another so the figure flows from panel to panel rather than changing abruptly at each joint. (7.6.1)
○ Premanufactured sets — matched within a set, not set to set (economical)
○ Sequence-matched panels — laid up and installed in flitch order across the wall (Custom feature)
○ Blueprint-matched panels and components — continuous figure to field dimensions (Premium)
NOTE Sequence matching lays up the panels for a wall from one flitch in the order they are cut and installs them in that order, so the grain progresses naturally across the wall. (7.6.2)
NOTE Blueprint matching is the most exacting: each panel and each component (including the panels over and around doors and openings) is sized and cut to the actual field dimensions from the shop drawings so the veneer figure is continuous across the entire elevation as drawn. (7.6.3)
NOTE Premanufactured sets are matched within each set but not from set to set, and are used where individual panels are not installed in a continuous run. (7.6.4)
7.7 Panel Product and Core
Particleboard core (ANSI A208.1) — standard veneered and laminate paneling
MDF core (ANSI A208.2) — thin face veneer, painted and routed profiles
Veneer-core hardwood plywood (ANSI/HPVA HP-1) — lighter, better edge screw-holding
Moisture-resistant (MR) core — paneling in humid or incidental-wet locations
7.7.1Veneered and laminate-faced paneling shall be built on a flat, stable manufactured core rather than on solid wood.
NOTE Particleboard core (ANSI A208.1) is flat, dimensionally stable, economical, and the standard core for most veneered and laminate paneling; MDF core (ANSI A208.2) is denser and smoother with a superior machined edge, preferred for thin face veneers and opaque-painted profiled paneling and machining crisply for routed reveals and profiles; and veneer-core hardwood plywood (ANSI/HPVA HP-1) is lighter, holds fasteners well in its edges, resists incidental moisture better than particleboard, and is selected where weight or edge screw-holding matters or a bending plywood is required for a curved panel. (7.7.1.1)
7.8 Laminate-Faced Paneling
○ High-pressure decorative laminate, NEMA LD 3 vertical grade (VGS), with balancing backer
○ Not applicable — wood-veneer or solid-wood paneling
7.8.1Where paneling is faced with high-pressure decorative laminate rather than wood veneer, the laminate shall conform to NEMA LD 3 and shall be the vertical grade (VGS) appropriate to a wall surface.
7.8.2The laminate shall be balanced with a backing sheet on the reverse of the core so the panel does not warp toward the faced side.
NOTE Laminate-faced paneling is used where a durable, cleanable, color-stable wall surface is wanted without the cost and maintenance of a wood finish; it is not a substitute for a casework or countertop surface (see
Wood And Laminate Casework).
(7.8.2.1) 7.9 Adhesives
○ Manufacturer's standard adhesives suited to substrate and service (standard)
○ Low-VOC / low-emitting adhesives (green-building or sensitive occupancy)
7.9.1Adhesives used to bond veneer to core, to laminate components, and to install paneling shall be appropriate to the substrate and the service condition.
7.9.2Adhesives shall be low-emitting where a low-emitting-materials requirement applies.
NOTE Adhesives in composite-wood panel products are subject to the same formaldehyde-emission limits as the panels themselves. (7.9.2.1)
7.10 Fasteners
Concealed clips / French-cleat hanging system for panels; blind-nailed trim (standard)
Adhesive plus concealed mechanical fastening to blocking
Exposed finish nails set and filled to match (where concealment is not feasible)
7.10.1Trim and paneling shall be fastened with concealed fasteners wherever the grade and detail permit.
7.10.2Exposed face nailing shall be limited to where it is unavoidable, shall use finish nails set below the surface, and the holes shall be filled to match the finish.
NOTE Concealed methods — blind nailing through the tongue or back of a member, hanging clips and French cleats for panels, and adhesive in combination with mechanical fastening — produce the clean, fastener-free face expected at Custom and Premium grade. (7.10.2.1)
7.11 Fire-Retardant Treatment
○ Class A — flame spread 0-25, smoke developed 0-450 (exits, vertical exit enclosures, high-occupancy)
○ Class B — flame spread 26-75, smoke developed 0-450 (corridors and many assembly/business areas)
○ Class C — flame spread 76-200, smoke developed 0-450 (rooms and areas where permitted)
○ Not regulated as interior finish at this location
○ Pressure-impregnated FRTW, AWPA U1 Category UCFA, Interior Type A, labeled
○ Listed fire-retardant / intumescent coating as basis of the rated assembly
○ Inherently compliant assembly without treatment (thin veneer over noncombustible substrate)
○ Not required — woodwork not regulated as interior finish at this location
7.11.1Where the trim or paneling is regulated by the building code as an interior wall or ceiling finish, the woodwork shall meet the surface-burning classification required for the occupancy and location under ASTM E84 (or UL 723).
7.11.2Fire-retardant-treated wood shall be provided where that classification cannot otherwise be achieved.
7.11.3Interior fire-retardant-treated wood shall be pressure-impregnated and classified under AWPA U1, Use Category UCFA (interior, weather-protected), and shall carry the treater's classification label.
7.11.4The treatment shall be Interior Type A so that the woodwork does not gain excessive moisture or lose its fire-retardant performance under the humidity swings of an occupied building.
7.11.5A listed intumescent or fire-rated coating applied over untreated wood shall be used only where it is the basis of the listed assembly.
7.11.6The treatment shall be applied before the woodwork is milled to its final profile to the extent practicable.
7.11.7Any field cuts in treated wood shall be re-treated with the manufacturer's field-applied fire-retardant where required to maintain the classification.
7.11.8The Contractor shall submit the ASTM E84 test report for the assembly as it will be installed, which governs whether treatment is needed.
NOTE Fire-retardant treatment is a chemical pressure treatment of the wood, not a surface coating; an intumescent or fire-rated coating applied over untreated wood is a different approach. (7.11.8.1)
NOTE A thin wood veneer (typically 1/28 in. or thinner) bonded to a noncombustible or fire-rated substrate often achieves a Class A classification as an assembly without treating the wood, because the small mass of the veneer cannot sustain flame spread; the ASTM E84 report for the actual assembly governs whether treatment is needed. (7.11.8.2)
○ TSCA Title VI / CARB Phase 2 compliant (mandatory baseline)
○ No-added-formaldehyde (NAF) composite wood
○ Ultra-low-emitting-formaldehyde (ULEF) composite wood
7.12.1All composite-wood panel components of the trim and paneling — particleboard, MDF, and hardwood plywood — shall comply with the formaldehyde emission standards of EPA TSCA Title VI (40 CFR Part 770) and CARB ATCM 93120 (Phase 2), and shall be labeled or certified accordingly.
7.12.2Where the project pursues a low-emitting-materials credit or serves a sensitive occupancy (healthcare, schools, childcare), no-added-formaldehyde (NAF) or ultra-low-emitting-formaldehyde (ULEF) composite wood should be specified.
7.12.3Emissions may be verified by small-scale chamber testing under ASTM D5116 where required by the contract documents.
NOTE EPA TSCA Title VI (40 CFR Part 770) and CARB ATCM 93120 (Phase 2) set identical emission limits, and compliance is mandatory for composite-wood products sold in the United States and is not optional. (7.12.3.1)
8 Fabrication
8.1 Grade and Joinery
○ Coped inside corners, mitered outside corners, scarfed running joints (standard)
○ Mitered all corners (where profile or material requires)
8.1.1Trim, paneling, and ornamental woodwork shall be fabricated to the requirements of the specified grade, with members machined, assembled, and finished in the shop to the maximum extent practicable so that field work is limited to fitting, joining at the necessary field joints, and installation.
8.1.2Profiles shall be milled true and continuous.
8.1.3Joints in running trim shall be kept to the minimum the lengths and the grade allow.
8.1.4Where a running joint is unavoidable it shall be a scarf or mitered-and-splined joint that closes tight and is located inconspicuously, not a butt joint at a visible location.
8.1.5Coped joints shall be used at inside corners of profiled running trim, and mitered joints at outside corners, so the profile reads continuously around the corner.
8.1.6Stile-and-rail paneling shall be joined with mortise-and-tenon or equivalent concealed joinery appropriate to the grade.
8.2 Panel Flatness and Matching
8.2.1Panel faces shall be flat within the tolerance allowed by the specified grade.
8.2.2The veneer leaf match, assembly match, and panel-to-panel sequence shall be executed as scheduled and as shown on the approved veneer-layout drawing.
8.2.3Veneer shall be balanced — a face veneer on the show side shall be balanced by a backing veneer of comparable thickness and expansion on the reverse — so the panel does not cup toward the face veneer.
NOTE An unbalanced veneered panel will cup over time no matter how flat it leaves the press. (8.2.3.1)
8.3 Stile-and-Rail and Raised-Panel Construction
○ Floating field panel in grooved frame (allows seasonal movement — standard for stile-and-rail)
○ Not applicable — flat-panel or slat system
8.3.1In stile-and-rail paneling, the field panel shall float in the grooved frame of stiles and rails rather than being glued fast on all edges, so the panel can expand and contract with seasonal moisture change without splitting itself or forcing the frame apart.
8.3.2A raised (profiled) field panel shall likewise float in the frame.
NOTE This floating construction is the defining feature of traditional wood paneling and the reason it survives decades of seasonal movement; gluing or pinning a wide panel on all four edges is a fabrication error that guarantees a split panel. (8.3.2.1)
8.4 Wood Ceiling and Wall Slat Systems
NOTE In an acoustic slat system the slats are spaced over an acoustically absorptive backing and the reveal is the acoustic opening. (8.4.1)
Solid-wood or veneered slats on concealed carrier, open reveal
Acoustic slat system over absorptive backing (reveal is the acoustic opening)
Plank / tongue-and-groove ceiling or wall system
Not applicable — no slat or linear system
8.4.2Wood slat (linear) systems — parallel slats or planks mounted on a concealed carrier, backer, or grid with an open or acoustically backed reveal between slats — shall be fabricated as a coordinated system with the slat module, reveal, carrier, and end and edge conditions as shown on the drawings.
8.4.3Where the system is acoustic, the slat module and reveal shall not be altered in the field because they set both the appearance and the acoustic performance.
8.4.4Slat systems mounted on ceilings and high on walls are interior finishes and shall meet the required ASTM E84 classification for the location.
9 Finishing
9.1 Transparent Finish System
Factory catalyzed / conversion-varnish system (standard)
Factory UV-cured finish system (flat panel stock)
Factory pre-catalyzed lacquer (lighter-duty)
Field-applied finish (where factory finishing is not feasible)
9.1.1Transparent finishes — clear and stained systems that show the wood grain — shall be applied as a system meeting the requirements of the specified AWS / ANSI/AWI grade.
9.1.2The finish system, stain color, and sheen shall be as scheduled.
9.1.3The stain shall be sampled and approved on the actual species and cut because the same stain reads very differently on different species and cuts.
NOTE A factory-applied catalyzed (conversion-varnish or comparable two-component) finish is the commercial default for transparent-finished trim and paneling because it is harder, more chemical- and moisture-resistant, and more uniform than a field finish and is cured under controlled conditions before delivery, while UV-cured finishes provide a hard, fast-cured factory finish on flat panel stock. (9.1.3.1)
9.2 Opaque (Paint) Finish System
Factory catalyzed or UV-cured pigmented finish (standard for profiled paneling)
Factory primed; field topcoat by painting trade (running trim)
Field primed and painted by painting trade
9.2.1Opaque finishes — pigmented systems that hide the wood — shall be applied as a system meeting the specified grade.
9.2.2Where the trim is field-painted, the woodwork shall be furnished primed or factory-prime-sealed so the field topcoats lie down evenly.
9.3 Factory Versus Field Finishing
○ Factory-finished (paneling and transparent-finished trim — standard)
○ Field-finished (opaque running trim integrated with painted walls)
○ Factory-finished paneling; field-finished running trim (mixed by category)
9.3.1The choice between factory and field finishing shall be made per category of work and stated on the finish schedule.
9.3.2Mixing factory- and field-finished pieces of the same exposed transparent woodwork shall be avoided because the two finishes will not match.
NOTE Factory finishing is preferred for paneling and transparent-finished trim because the finish is applied and cured under controlled temperature, humidity, and dust conditions and is more uniform and durable than a field finish and because spraying flat in the shop produces a better film than brushing or rolling in place, while field finishing is used for opaque running trim integrated with the painted wall (joints filled and caulked, trim disappearing into the wall color) and for woodwork that must be scribed, cut, and fitted in the field before it can be finished. (9.3.2.1)
9.4 Finish Sheen
○ Satin
○ Semi-gloss
○ Matte / flat
○ Gloss
10 Installation
10.1 General
10.1.1Trim and paneling shall be installed after the space is enclosed, conditioned, and dry, after wet finishes are complete, and after the woodwork has acclimatized to the interior conditions.
10.1.2The Contractor shall install the woodwork to the requirements of the specified installation grade (ANSI/AWI 0620 or the AWS installation grade), plumb, level, true, and securely fastened, with tight, properly fitted joints, uniform reveals, and the figure and sequence of veneered panels installed in the order shown on the approved veneer-layout drawing.
10.2 Blocking and Backing
NOTE Blocking is furnished and installed under the wall and ceiling trades and coordinated on the woodwork shop drawings. (10.2.1)
○ Yes — continuous blocking/backing verified at all panel, slat-carrier, and heavy-trim locations
○ Not applicable — light trim fastened to framing/furring only at this location
10.2.2The Contractor shall verify before installation that solid, continuous in-wall and in-ceiling blocking or backing has been provided at every panel-hanging location, at heavy and large panels, at slat-system carriers, and at trim that cannot be reliably fastened to framing or furring alone.
10.2.3The Contractor shall confirm the presence and location of blocking and shall notify the Architect of missing or mislocated blocking before proceeding.
10.2.4Paneling and slat systems hung on gypsum board without blocking will pull loose and shall not be permitted.
10.3 Hanging Systems
○ Concealed hanging clips / Z-clips on blocking (removable, adjustable — standard)
○ Hanging-rail system on blocking
○ Adhesive plus concealed mechanical fastening to continuous backing
○ Concealed face-fastening with set-and-filled finish nails (light paneling only)
10.3.1Wall paneling should be installed on a concealed hanging system — interlocking metal or wood Z-clips (French cleats) or a hanging-rail system fastened to the blocking — rather than face-fastened, so the panels carry no visible fasteners, hang flat and plumb, can be shimmed off an uneven wall to a true plane, and can be removed individually for access or replacement without damage.
10.3.2Face-fastening shall be used only where a hanging system is impractical and the fasteners can be concealed in a joint or filled.
10.4 Scribing and Fitting
10.4.1Paneling and trim that meet walls, floors, ceilings, columns, and adjacent finishes shall be scribed to fit the contour of the adjacent surface so the joint is tight and uniform.
10.4.2Scribe pieces, fillers, and closures shall be provided to close the gaps between panels and between paneling and adjacent construction, finished to match the woodwork.
10.4.3Reveals and shadow lines designed into the work shall be held uniform.
NOTE Surfaces in a building are rarely flat or plumb, so a panel set against an out-of-plumb wall without scribing leaves a tapered gap, and an uneven reveal is the most visible defect in a paneled wall. (10.4.3.1)
10.5 Expansion and Movement
☐ Floating field panels in stile-and-rail frames
☐ Reveals / slip joints between panels to absorb movement
☐ Fastening that restrains panels while allowing cross-grain movement
☐ Trim detailed to cross building expansion joints
10.5.1The installation shall accommodate the seasonal expansion and contraction of the wood.
10.5.2Running trim that crosses a building expansion joint shall be detailed to move with the joint.
10.5.3Paneled walls and long runs of trim shall be installed so the wood can move without buckling or opening visible gaps — floating field panels in their frames, slip joints and reveals that absorb movement, and fastening that holds the woodwork to the wall while letting it expand and contract across its width.
10.5.4Paneling shall not be fastened so rigidly across its full width that seasonal swelling has nowhere to go.
NOTE Fastening paneling rigidly across its full width produces a buckled wall in the humid season and open joints in the dry season. (10.5.4.1)
10.6 Slat-System Installation
10.6.1Wood slat and linear systems shall be installed on their carriers to the module and reveal shown, with carriers fastened to verified blocking, slats aligned and the reveal held uniform, and end, edge, and transition conditions executed per the details.
10.6.2Where the system is acoustic, the absorptive backing shall be installed continuously behind the open reveals as the assembly was tested, because the backing, not the wood, provides the absorption.
11 Testing and Inspection
11.1 Field Quality Control
11.1.1After installation the Contractor shall inspect the trim and paneling for grade compliance, alignment, matching, and finish.
11.1.2Panels shall be checked for plumb, flatness, uniform reveals, and correct veneer sequence.
11.1.3Running trim shall be checked for tight coped and mitered joints, true profiles, and inconspicuous running joints.
11.1.4Exposed surfaces shall be checked for damage and finish defects.
11.1.5Woodwork that does not meet the specified grade, that is out of alignment, that breaks the veneer sequence, or that is damaged shall be corrected or replaced.
11.2 Fire Classification Verification
11.2.1Where the woodwork is regulated as an interior finish, the Contractor shall make available the ASTM E84 (or UL 723) classification documentation and, for fire-retardant-treated wood, the AWPA U1 treatment label, for the Authority Having Jurisdiction's inspection.
11.2.2Field cuts in fire-retardant-treated wood that expose untreated material shall be field-treated where required to maintain the classification.
12 Delivery, Storage, and Handling
12.1 Delivery and Storage
○ Maintain woodwork within the service RH range; store flat in conditioned space (standard)
○ Wrapped and climate-controlled transport and storage (Premium / sensitive species)
12.1.1Trim and paneling shall be delivered to the project only after the building is enclosed and conditioned and shall be stored flat and fully supported in the conditioned space, protected from moisture, direct sunlight, and physical damage, with air circulation around stacked material during acclimatization.
12.1.2Veneered panels shall be stored flat and stickered, never on edge or leaning, because a panel stored on edge or leaning takes a set and warps.
12.1.3Finished woodwork shall be protected from impact, abrasion, and finish-damaging chemicals through delivery, storage, installation, and the remainder of construction.
12.2 Protection During Construction
12.2.1Protective coverings shall be installed over completed paneling and trim and shall remain until substantial completion to protect the work from damage by other trades.
12.2.2The coverings shall not trap moisture against the woodwork or mark or adhere to the finish.
13 Warranty
13.1 Warranty Period and Coverage
1 year from substantial completion — standard
2 years from substantial completion
5 years from substantial completion (Premium / institutional programs)
13.1.1The manufacturer and the Contractor shall warrant the trim, paneling, and ornamental woodwork against defects in materials and workmanship for the specified period, including warping, cupping, or twisting beyond the grade tolerance, delamination of veneer, open or telegraphing joints, finish failure, and failure of the attachment or hanging system under normal use.
13.1.2The warranty shall exclude damage caused by moisture exposure or interior humidity outside the specified service range (where the woodwork was installed and the building maintained within that range), by abuse, and by modifications made without authorization.
13.1.3The Contractor shall warrant the installation — including blocking verification, attachment and hanging, scribing and fitting, joint quality, veneer-sequence installation, and accommodation of expansion and movement — for the specified period.
13.1.4Deficiencies attributable to installation workmanship shall be corrected by the Contractor at no cost to the Owner.
14 Maintenance
14.1 Owner Maintenance and Care
14.1.1The Contractor shall provide finish-specific care and maintenance instructions and an inventory of attic-stock matching trim, panel blanks, and touch-up finish for the Owner's future repairs.
14.1.2The Owner should maintain the interior temperature and relative humidity within the specified service range for the life of the woodwork.
14.1.3Cleaning shall use the method appropriate to the finish, and finish refresh and repair shall use the attic-stock touch-up materials and the manufacturer's recommended products.
NOTE The most common cause of in-service paneling and trim failure is not a defect in the woodwork but a building allowed to swing far outside the humidity range the woodwork was fabricated for, which drives the cupping, splitting, and open joints that the floating-panel and movement provisions can only partly absorb. (14.1.3.1)