Specification:Replication of period exterior wooden objects

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=GENERAL=

DESCRIPTION
 This specification provides guidance for replicating wood period objects. This specification has been developed for use on historic properties (defined as any district, site, building, structure, or object that is listed in or eligible for listing in the National Register of Historic Places) and provides an overview of accepted practices. Site-specific specifications, when appropriate, will be provided by the Architect.  All work described herein and related work must conform to the Secretary of Interior’s Standards for the Treatment of Historic Properties. The Contractor shall provide all labor, materials, equipment, and operations required to complete the rehabilitation work indicated herein. All work described herein and related work must have the approval of a Cultural Resources Manager, Conservator, Historic Architect, or other professional who meets the standards outlined in the Secretary of the Interior’s Standards – Professional Qualifications Standards pursuant to 36 CFR 61. Such person is referred to in this document as the Architect. 

SECTION INCLUDES
 Measurement and Replication of Existing Objects Fabrication of Object (shutters, columns, column capitals, etc.)</li> </ol>

RELATED SECTIONS
<ol type="A"> Section 06200.02 – Wood Properties and Appropriate Lumber </li> Section 06220.01 – Replication of Period Profiles</li> </ol>

SUBMITTALS
<ol type="A"> Repair Schedule: Submit a detailed schedule of objects to be replicated including procedures for removal of deteriorated features, measuring of existing objects and fabrication of new objects. Coordinate all necessary removal, fabrication, delivery and installation work with the general contractor and other applicable trades. The extent of replacement is subject to Architect approval.</li> Shop Drawings: The Contractor shall submit shop drawings for all new millwork required for the project. Shop drawings shall show dimensions, include full-size details as necessary, and be in conformance with the Architectural Woodwork Quality Standards (Eighth ed. Vers. 2) guidelines for architectural millwork shop drawings. Wood species shall be clearly indicated.</li> Samples: The Contractor shall one sample of each type of wood object to be fabricated (scale to be determined by Architect). Samples are of the same species to be used in the work. If full-size, approved sample may be used in preparation of required mock-ups. </li> Product Literature: Submit manufacturer’s product literature to architect for all proprietary products specified. Product literature shall include specification data, Material Safety Data Sheets and instructions for storage, handling and use.</li> </ol>

QUALITY ASSURANCE
<ol type="A"> Work Experience: The Contractor shall have demonstrated experience approved by the Architect, ideally a minimum of seven years experience in the production of custom architectural millwork and the replication of period objects and shall have successfully completed at least three projects of similar scope within the previous five years. He/she shall demonstrate a working knowledge of The Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring &amp; Reconstructing Historic Buildings.</li> Warranty: Ten (10) year warranty on materials and workmanship for replicated wood objects.</li> </ol>

MOCK-UPS
<ol type="A"> Procedure

Prior to start of wood replication work, prepare one mock-up for each type of wood object (shutter, column, column capital, etc.) indicated to be replaced. Prepare mock-up panels on existing woodwork to demonstrate quality of materials and workmanship. Obtain supervising Architect’s acceptance of visual qualities before proceeding with the work. Retain acceptable panels in undisturbed condition, suitably marked, during construction as a standard for judging completed work.</li> More than one mock-up may be required to be acceptable for approval. The Contractor shall prepare at least three mock-ups of each type (moveable and fixed), if necessary, without further compensation. The approved mock-up shall become part of the work and shall serve as the quality standard for all similar work.</li> </ol>

DELIVERY, STORAGE AND HANDLING
<ol type="A"> Deliver restoration materials to the project site in manufacturer’s or distributor’s packaging, undamaged, complete with instructions and Material Safety Data Sheets as applicable. Store any required fillers, putties and adhesives within the temperature range recommended by the manufacturer and away from direct sunlight.</li> Deliver all materials only when the project is ready for installation and the general contractor has provided a clean storage area as defined in the Architectural Woodwork Quality Standards as adopted by the Architectural Woodwork Institute (AWI). Coordinate deliveries of new millwork and restoration of existing millwork to avoid delays in the project. Coordinate storage of new materials at the site with the Owner’s representative. Allow adequate notice to Owner’s representative of scheduled millwork deliveries.</li> Fabricated wood objects shall be delivered to the site in crates or other sturdy packaging to prevent loss and damage. Store all wood fabrications indoors in a dry, secure location above grade, protected from moisture and with adequate ventilation, until ready for installation. Store off the ground on pallets or dunnage.</li> Allow new woodwork to acclimate at least one week to ambient temperature and humidity prior to installing.</li> </ol>

PROJECT / SITE CONDITIONS
<ol type="A"> The Contractor is responsible for protecting existing adjacent materials during the execution of the work. Provide all necessary protection and work procedures to avoid damage to existing material assemblies not a part of the work of this Section.</li> All completed work shall be adequately protected from damage by subsequent building operations and effects of weather. Protection shall be by methods recommended by the manufacturer of installed materials and as approved by the supervising Architect.</li> <li>Maintain temperature and relative humidity during fabrication, storage and finishing operations so that moisture content values for woodwork at time of installation do not exceed the specified range.</li> <li>The Contractor shall be responsible for disposal of waste materials and other debris associated with the work of this Section in accordance with local, state and federal environmental regulations.</li> <li>The Contractor shall coordinate the fabrication and delivery of new wood objects with other trades including, but not necessarily limited to, carpentry, plaster and painting to avoid delays in the project.</li> </ol> =PRODUCTS=

MEASUREMENT OF EXISTING OBJECT
Equipment to document size and shape of object: <ol type="A"> <li>Measuring tape </li> <li>Bevel square </li> <li>Profile gauges </li> <li>Pencil and paper (for tracings and rubbings) </li> <li>Camera and tripod </li> <li>Flashlight </li> <li>Calipers </li> <li>Dividers </li> <li>Carpenter’s squares </li> <li>Compasses </li> <li>Templates and curves</li> </ol>

FABRICATION OF NEW WOOD OBJECTS
<ol type="A"> <li>General: Where possible, existing historic wood elements should be retained and repaired. Where replacement is required due to the nature or extent of deterioration, replicated wood objects should be as close as possible to the original in size, shape, detail and finish. Accurate measurement of the existing object, as well as a thorough investigation into its component materials and finishes, is essential. A true “in kind” replacement will also match new material to old with regards to species, quality (e.g. first vs. second growth), cut (e.g. quarter sawn vs. flat sawn), grain direction and pattern, and even tool marks. </li> <li>Selection of Wood Wood for in-kind replacement should be selected based on the material it is replacing and the qualities outlined in Section 06200.02, Wood Properties and Appropriate Lumber.</li> <li>Wood Materials <ol> <li>New exterior woodwork to be painted shall be constructed of a durable wood suitable for outdoor paint finishes and approved by the Architect. </li> <li>New exterior woodwork for transparent finish shall match the species, cut, grain direction and pattern of the existing or historic woodwork. Match grade if known. </li> <li>Moisture content: <li>Not to exceed 12 percent for trim and millwork that is 1¼ inch or less in thickness.</li> <li>Not to exceed 15 percent for trim and millwork four inches or fewer in thickness.</li> </ol> </li> <li>Grading: <li>NHPMA Official Grading Rules, 1978: All species, C and better Select.</li> <li>WWPA Standard Grading Rules, 1988: All species C Select except Choice for Idaho White Pine.</li> <li>WCLIB Standard Grading and Dressing Rules, 1984: All species, C and better VG.</li> <li>NHLA Grading Rules, First Grade unless otherwise indicated.</li> <li>NELMA Grading Rules, 2006, Select Grade D or better.</li> </ol> </li> </ol> </li> </ol> =EXECUTION=

GENERAL
<ol type="A"> <li>Quality Standard: Unless otherwise indicated, comply with AWI Architectural Woodwork Quality Standards for grades of architectural woodwork, construction, finishes and other requirements.</li> </ol>

MEASUREMENT OF EXISTING OBJECTS
<ol type="A"> <li>General: The purpose of replicating existing historic wood objects is to allow in-kind replacement of damaged, deteriorated or missing woodwork per Section 06400.01, Historic Wood In Kind Replacement. In most instances, replication of wood objects will be outsourced to a qualified millwright or cabinet shop that is already in possession of a shaper knives, lathe patterns, etc. to accommodate a variety of period objects. Before custom fabrication is undertaken, a variety of sources and pattern books for historic objects should be consulted to determine if a stock replacement is available.</li> <li>Measuring and Drawing Existing Objects: <ol> <li>Establish accurate horizontal and vertical datum lines before measuring.</li> <li>If possible, compensate for paint layers that tend to obscure the sharpness of detail. Where accumulated paint layers make it difficult to obtain an accurate measurement of an existing profile, carefully remove paint in consultation with supervising Architect.</li> <li>Select a recording instrument suitable for size and complexity of object to be replicated, e.g. profile gauge, calipers, carpenter’s square. Tracings, pencil rubbings, photographs, or the use of a flashlight to provide raking light can also be helpful.</li> <li>Calipers, dividers and carpenter's squares are useful in measuring objects that are round in cross-section, such as balusters, decorative urns and spheres, and columns. When determining column diameters, care must be taken to account for entasis-- the slight convex curvature of the vertical profile of the column - if it is present. Note: In Roman entasis, for example, curvature begins at 1/3 the distance from the bottom of the base to the top of the capital; in Greek entasis, curvature begins at the base. Field notes and detail drawings should reference heights from the base at which diameters were determined.</li> <li>Record dimensions to the 1/8th, 1/16th or 1/32 of an inch depending on size of object and level of detail. </li> <li>Translate measurements into elevation and section drawings with numbered or lettered details. Details are typically drawn at 1- 1/2'=1'-0&quot; or larger. AutoCAD drawings are helpful because of the possibility for infinite scale views.</li> </ol> </li> </ol>

FABRICATION OF OBJECT
<ol type="A"> <li>General: Replicated wood objects should mimic the original in size, shape, detail, color, and finish. Accurate measurement of the existing object, as well as a thorough investigation into its component materials and finishes, is essential. A true “in kind” replacement will also match new material to old with regards to species, quality (e.g. first vs. second growth), cut (e.g. quarter sawn vs. flat sawn), grain direction and pattern, and even tool marks. </li> <li>Selection of Wood: Wood for in-kind replacement should be selected based on the material it is replacing and the qualities outlined in Section 06200.02, Wood Properties and Appropriate Lumber.</li> <li>Procedure: <ol> <li>Contractor shall provide shop drawings of all millwork for review by the Architect. The Contractor (or subcontractor, if outsourcing fabrication) shall not begin fabrication of said millwork until shop drawings have been released and submitted samples have been approved.</li> <li>Shop drawings must indicate the physical dimensions and details or profiles of all elements of the work, including the location of different grades, species, and/or finishes.</li> <li>As an additional record of repairs, all replicated wood shall be date stamped on the back prior to installation.</li> <li>All objects to be fabricated to American Woodwork Quality Standards. Custom, Premium, or Economy grades are to be specified in Scope of Work and/or clarified by supervising Architect.</li> <li>It is the responsibility of the millwork fabricator to observe the project before bid and match all materials for species, grain and overall appearance. The profiles and details of all millwork shall match existing or shall be as detailed on the contract drawings and the approved shop drawings.</li> <li>Fabricate custom millwork in maximum practical lengths to minimize joints. Prepare all work for delivery to the site in lengths suitable for passage through the building interior. </li> <li>Where practicable, the shop assembles and finishes items of built-up millwork. When it is necessary to cut and fit on–site, provide materials with ample allowance for cutting. Provide adequate material stock for scribing and site cutting.</li> <li>All glue joints shall be glued under pressure using Type 1 waterproof glue and allowed to cure for a minimum of 24 hours.</li> <li>Machine-sand exposed flat members and square edges. Machine-finish semi-exposed surfaces. </li> <li>1For painted surfaces: All custom millwork that is to be painted shall be primed with two coats of primer and hand sanded between coats. Back prime all concealed surfaces of exterior trim. Exterior columns shall be coated on the interior with an appropriate weather fast paint. </li> </ol> </li> </ol>

FINAL REPORT
<ol type="A"> <li>After completion of the replication work, the Contractor shall submit a final report including copies of approved submittals, initial assessment of existing historic wood and determination of objects to be replaced (itemized by type and location, identifying characteristics including wood species and extent/type of deterioration), photographs taken during measurement of existing profiles and during and after fabrication of new objects, and a written description of the executed work. </li> </ol>