Historic Preservation - Technical Procedures
General Guidelines For Cutting And Patching
Federal Bldg/Uspo/Spokane, Wa - Gsa/Pbs
Cutting And Patching
General Guidelines For Cutting And Patching
Spec title: General Guidelines for Cutting And Patching
Procedure code: 0104501S
Source: Federal Bldg/USPO/Spokane, WA - GSA/PBS
Division: General Requirements
Section: Cutting And Patching
Last Modified: 02/24/2012
Details: General Guidelines For Cutting And Patching
GENERAL GUIDELINES FOR CUTTING AND PATCHING ORIGINAL WORK
A. This procedure includes general guidelines to follow when performing cutting and patching in original work.
A. "Cutting and patching" refers to cutting into existing construction to provide for the installation or performance of other work, and the subsequent fitting and patching required to restore surfaces to their original condition.
1. Cutting and patching is performed for coordination of the work, to uncover work for access or inspection, to obtain samples for testing, to permit alterations to be performed, or for other similar purposes.
2. Cutting and patching performed during the manufacture of products, or during the initial fabrication, erection or installation processes is not considered to be "cutting and patching" under this definition. Drilling of holes to install fasteners and similar operations are also not considered to be "cutting and patching".
3. "Selective Demolition" is recognized as related-but-separate category of work, which may or may not include cutting and patching as defined in this procedure.
A. Procedural Proposal for Cutting and Patching: Where prior approval of cutting and patching is required, submit proposed procedures for this work well in advance of the time work will be performed, and request approval to proceed. Include the following information, as applicable, in the submittal:
1. Describe nature of the work and how it is to be performed, indicating why cutting and patching cannot be avoided. Describe anticipated results of the work in terms of changes to the existing site conditions, including structural, operational and visual changes, as well as how historic materials or other significant elements may be impacted by the proposed cutting and patching.
2. List products to be used, and firms (including their qualifications), that will perform the work.
3. Give dates when the work is expected to be performed.
4. List utilities that will be disturbed or otherwise be affected by work, including those that will be relocated and those that will be out-of-service temporarily. If utility service will be disrupted, an estimated time that it will be out of operation must be included in the proposal.
5. When cutting and patching of structural work involves the substitution, movement, removal or addition of structural elements or reinforcement of any kind, submit engineering details and calculations that have been signed and stamped by a suitably experienced and licensed professional to show how the new work is integrated with the original structure to satisfy the requirements of the undertaking.
6. Indicate changes to designated landmark areas or highly rated HBPP zones.
7. All welding and/or hotwork requires formal, written notification to the Building Manager no later than the first thing in the morning of each day such work is to be done. No welding or hot work is permitted without such prior notification.
1.04 QUALITY ASSURANCE
A. The General Contractor shall do all cutting and patching of wall and ceiling surfaces for the removal, relocation or installation of new piping, conduit, electrical boxes, asbestos abatement, PCB removal, and also where such services have been removed or abandoned.
1. Cutting which will disturb the asbestos material shall be done under the direction of the Asbestos Abatement subcontractor and will be properly documented in writing.
B. Cutting and patching of all nonstructural concrete floors for Mechanical and Electrical work shall be done by the respective subcontractors in accordance with the provisions of this section under the supervision of the General Contractor.
C. Cutting and patching of all walls for ducts shall be done by the Mechanical subcontractor in accordance with the provisions of this section under the supervision of the General Contractor.
D. Requirements for Structural Work: As in 1.03 A.5 above, when cutting and patching of structural work involves the substitution, movement, removal or addition of structural elements or reinforcement of any kind, submit engineering details and calculations that have been signed and stamped by a suitably experienced and licensed professional to show how the new work is integrated with the original structure to satisfy the requirements of the undertaking.
Cutting and patching structural work in a manner that would result in a reduction of load-carrying capacity or of load-deflection ratio is not acceptable. All work must have the written approval of project's Structural Engineer in advance.
E. Before cutting and patching the following categories of work, obtain approval to proceed from both the GSA Contracting Officer and the GSA Regional Historic Preservation Officer:
1. Structural steel.
2. Miscellaneous structural metals, including lintels, equipment supports, stair systems and similar categories of work.
3. Structural concrete.
4. Foundation construction.
5. Timber and primary wood framing.
6. Structural decking.
7. Bearing and retaining walls.
8. Piping, ductwork, vessels and equipment.
9. Shoring, bracing, and sheeting.
10. Primary operational systems and equipment.
11. Water/moisture/vapor/air/smoke barriers, membranes and flashings.
12. Noise and vibration control elements and systems.
l3. Control, communication, conveying, and electrical wiring systems, including fire and life safety systems.
F. Visual Requirements: Do not cut and patch work exposed on the building's exterior or in its occupied spaces in a manner that would, in the Contracting Officer's opinion, result in lessening the building's aesthetic qualities.
Do not cut and patch work in a manner that would result in substantial visual evidence of cut and patch work. Any work judged by the Contracting Officer to be done in a visually unsatisfactory manner must be removed and replaced.
G. Retain a recognized, experienced, and specialized firm to cut and patch the following categories of exposed work.
1. Processed concrete finishes.
2. Stonework and stone masonry.
3. Ornamental metal.
4. Matched-veneer woodwork.
6. Stucco and ornamental plaster.
8. Finished wood flooring.
10. Wall covering.
11. HVAC enclosures, cabinets or covers.
A. General: Except as otherwise indicated, or as directed by the Contracting Officer, materials for cutting and patching must be identical to existing materials. If identical materials are not available or cannot be used, use pre-approved materials that match existing adjacent surfaces to the fullest extent possible with regard to visual effect. Use materials for cutting and patching that will result in equal-or-better performance characteristics in comparison to the original.
1. The use of a trade name and suppliers name and address is to indicate a possible source of the product. Products of the same type from other sources shall not be excluded provided they possess like physical and functional characteristics.
A. Before cutting, examine the surfaces to be cut and patched and the conditions under which the work is to be performed. If unsafe or otherwise unsatisfactory conditions are encountered, take corrective action before proceeding with the work.
1. Before the start of cutting work, meet at the work site with all parties involved in cutting and patching, including mechanical and electrical trades. Review areas of potential interference and conflict between the various trades. Coordinate layout of the work and resolve potential conflicts before proceeding.
A. Temporary Support: To prevent failure provide temporary support of work to be cut. Do not endanger other work. Provide adequate support during cutting and patching so as to prevent damage;
B. Protection: Protect adjoining surfaces during cutting and patching to prevent damage. Provide protection from cold and moisture as directed by the patching product manufacturer.
1. Avoid interference with the use of adjoining areas or interruption of free passage to adjoining areas to the extent possible given the scope of work. Utilize safe workplace practices.
3.03 ERECTION, INSTALLATION, APPLICATION
A. General: Employ skilled workers to perform cutting and patching work. The tradespeople who have the skill to be doing the patching should be the ones doing the cutting. Except as otherwise indicated or as approved by the Contracting Officer, proceed with cutting and patching at the earliest feasible time (given proper notice) and complete work without delay.
B. Cutting: Cut the work using methods that are least likely to damage work to be retained or adjoining work.
1. In general, where cutting is required use hand or small power tools designed for sawing or grinding, not hammering and chopping. Cut through concrete and masonry using a cutting machine such as a Carborundum saw or core drill to insure a neat hole.
2. Cut holes and slots neatly to size required with minimum disturbance of adjacent work. To avoid marring existing finished surfaces, cut or drill from the exposed or finished side into concealed surfaces. Temporarily cover openings when not in use, taking to consideration life safety and fire regulations for occupied spaces.
3. Comply with other applicable requirements where cutting and patching requires excavating and backfilling.
4. If the area includes utility services enclosed in pipe or conduit that are scheduled to be removed as part of the undertaking, these should be disconnected and removed before the before cutting and patching nearby as their later disturbance later could damage the new patch.
Be on the alert for undocumented and unprotected cabling for alarms, computer networks, and security systems that often follow the same path as conduit and piping. These are frequently found passing through enclosed spaces.
Any cut-off conduit or pipe in walls or partitions is to be removed when possible. Any remaining openings need to be sealed to meet fire and building codes, and shall prevent the entrance of moisture or other foreign matter into the space.
C. Patching: Patch with seams which are durable and as invisible as possible. Comply with specified tolerances for the work.
1. Where feasible, inspect and test patched areas to demonstrate integrity of work.
2. Restore exposed finishes of patched areas and where necessary extend finish restoration into retained adjoining work in a manner which will eliminate evidence of patching and refinishing. Where a patch occurs in a smooth painted surface, extend the final paint coat over the entire unbroken surface which now contains the new patch (after that patched area has received proper prime and base coats).
3. Where removal of walls or partitions has newly extended one finished area into another, floor and wall surfaces in the new space shall be patched and repaired to provide an even surface of uniform color and appearance. If necessary, remove the existing floor and wall coverings and replace with new materials to achieve uniform color and appearance.
4. Patch, repair or re-hang existing ceilings as necessary to provide a surface with an even plane of uniform appearance.
A. Clean adjoining surfaces that become soiled due to the cutting and patching work.
END OF SECTION