07 01 50 19 Preparation for Re-Roofing.docx

VA Medical Center – Albany, NY Samuel S. Stratton Facility 2022 Chiller Plant Roof Replacement Date of Issue 2/14/2022

SECTION 0 701 50.19 - PREPARATION FOR RE-ROOFING

This pre-edited MasterSpec section specifies preparation for re-roofing and rehabilitation projects, including full and partial tear-off of existing roofing, patching and reinforcing existing roofing, and uplift securement. This Section is intended to take the place of Section 024116 "Selective Demolition" for re-roofing work. Included are options for salvaging and recycling of demolition and construction waste and management of refrigerant that are compatible with but not necessarily limited to compliance with sustainable design requirements.

GENERAL

SUMMARY

Section Includes:

Revise list below to suit Project.

Roof replacement preparation consisting of full roof tear-off of entire roof system.

Removal of flashings.

Edit "Related Information" Paragraph below as required to coordinate work specified in several sections. Only list sections that are actually included in the Project Manual and available to the Contractor.

Related Information:

Division 07 Section "Roof Specialties" for manufactured roof edge/fascia systems.

DESCRIPTION OF WORK

Coordinate Roof Area numbers with those indicated on roof drawing. Use in-line editing to revise as necessary.

Re-roofing preparation Work consists of the following:

Preparation for Roof Area Chiller Plant Roof:

Preparation for: Roof replacement.

Existing Roof Type: Aggregate surfaced BUR.

Existing Deck Type: Concrete deck.

Roof tear-off.

Removal and reinstallation of indicated components, accessories, and equipment.

MATERIALS OWNERSHIP

Except for items or materials indicated to be reused, reinstalled, or otherwise indicated to remain Owner's property, demolished materials shall become Contractor's property and shall be removed from Project site.

DEFINITIONS

Roofing Terminology: Refer to ASTM D1079 "Standard Terminology Relating to Roofing and Waterproofing" and glossary in applicable edition of NRCA's "The NRCA Roofing Manual: Membrane Roof Systems" for definition of terms related to roofing work in this Section.

For projects with preparation of multiple existing roof areas or roofing types, use schedule at end of Part 3 and delete this paragraph.

Existing Roofing System: Roofing system identified above, including roof covering/membrane, roof insulation, surfacing, and components and accessories between deck and roof covering/membrane.

Roof Re-Cover Preparation: Existing roofing membrane that is to remain and be prepared for reuse or rehabilitation.

Full Roof Tear-Off: Removal of existing membrane roofing system from deck.

Partial Roof Tear-Off: Removal of a portion of existing membrane roofing system from deck or removal of selected components and accessories from existing membrane roofing system.

Roof Re-Cover Preparation: Existing roofing membrane that is to remain and be prepared for installation of new roofing system over existing system.

Roof Rehabilitation Preparation: Existing roofing membrane that is to remain and be prepared for rehabilitation.

Remove: Detach items from existing construction and legally dispose of them off-site unless indicated to be removed and reinstalled.

Existing to Remain: Existing items of construction that are not indicated to be removed.

Construction Waste: Building and site improvement materials and other solid waste resulting from construction, remodeling, renovation, or repair operations. Construction waste includes packaging.

Demolition Waste: Building and site improvement materials resulting from demolition or selective demolition operations.

Disposal: Removal off-site of demolition and construction waste and subsequent sale, recycling, reuse, or deposit in landfill or incinerator acceptable to authorities having jurisdiction.

Recycle: Recovery of demolition or construction waste for subsequent processing in preparation for reuse.

Salvage: Recovery of demolition or construction waste and subsequent sale or reuse in another facility.

Salvage and Reuse: Recovery of demolition or construction waste and subsequent incorporation into the Work.

PREINSTALLATION MEETINGS

Retain "Preliminary Roofing Conference" Paragraph below for all reroofing projects.

Preliminary Roofing Conference: Before starting removal Work, conduct conference at Project site.

Coordinate with roofing preinstallation meetings specified in Division 07 roofing section(s).

Review methods and procedures related to roofing tear-off, including, but not limited to, the following:

Edit the list below to suit Project conditions.

Reroofing preparation, including roofing system manufacturer's written instructions.

Temporary protection requirements for existing roofing system components that are to remain.

Existing roof drains and roof drainage during each stage of reroofing, and roof-drain plugging and plug removal.

Construction schedule and availability of materials, Installer's personnel, equipment, and facilities needed to avoid delays.

Existing roof deck conditions requiring Owner's Consultant notification.

Existing roof deck removal procedures and Owner notifications.

Condition and acceptance of existing roof deck and base flashing substrate for reuse.

Structural loading limitations of roof deck during reroofing.

Base flashings, special roofing details, drainage, penetrations, equipment curbs, and condition of other construction that affect reroofing.

HVAC shutdown and sealing of air intakes.

Shutdown of fire-suppression, -protection, and -alarm and -detection systems.

Asbestos removal and discovery of asbestos-containing materials.

Governing regulations and requirements for insurance and certificates if applicable.

Existing conditions that may require Owner's Consultant notification before proceeding.

ACTION SUBMITTALS

Product Data: For each type of product indicated.

Retain paragraph below if Contractor may propose, or is required to propose, temporary roofing. Usually delete submittal if temporary roofing is specified in the Section Text.

Temporary Roofing: Include Product Data and description of temporary roofing system. If temporary roof will remain in place, submit surface preparation requirements needed to receive permanent roof, and submit a letter from roofing membrane manufacturer stating acceptance of the temporary membrane and that its inclusion will not adversely affect the roofing system's resistance to fire and wind.

INFORMATIONAL SUBMITTALS

Proposed Protection Measures: Submit report, including Drawings, that indicates the measures proposed for protecting individuals and property for environmental protection. Indicate proposed locations and construction of barriers.

"Schedule of Re-Roofing Preparation Activities" Paragraph below may be used to track Contractor's progress; it may also be used to determine that work will not interfere with Owner's operations.

Schedule of Re-Roofing Preparation Activities: Indicate the following:

Detailed sequence of re-roofing preparation work, with starting and ending dates for each activity. Ensure occupants' on-site operations are uninterrupted.

Interruption of utility services. Indicate how long utility services will be interrupted.

Coordination for shutoff, capping, and continuation of utility services.

Use of elevator and stairs.

Coordination of Owner's continuing occupancy of portions of existing building.

CLOSEOUT SUBMITTALS

QUALITY ASSURANCE

Installer Qualifications: Installer of new membrane roofing system.

PROJECT / FIELD CONDITIONS

Owner will occupy portions of building immediately below reroofing area.

Conduct reroofing so Owner's operations will not be disrupted.

Provide Owner with not less than 48 hours' written notice of activities that may affect Owner's operations.

Coordinate work activities daily with Owner so Owner can place protective dust or water leakage covers over sensitive equipment or furnishings, shut down HVAC and fire-alarm or -detection equipment if needed, and evacuate occupants from below the work area.

Retain subparagraph below if known impaired deck areas or if special protection is not provided below the work area.

Before working over structurally impaired areas of deck, notify Owner to evacuate occupants from below the affected area.

Verify that occupants below the work area have been evacuated before proceeding with work over the impaired deck area.

Protect building to be reroofed, adjacent buildings, walkways, site improvements, exterior plantings, and landscaping from damage or soiling from reroofing operations.

Maintain access to existing walkways, corridors, and other adjacent occupied or used facilities.

Retain first paragraph below if limiting construction loads on existing roof deck and building structure. Revise to suit Project.

Limit construction loads on roof to rooftop equipment wheel loads and uniformly distributed loads not exceeding recommendations of Contractor's professional engineer based upon site inspection and analysis.

Weather Limitations: Proceed with reroofing preparation only when existing and forecasted weather conditions permit Work to proceed without water entering existing roofing system or building.

Remove only as much roofing in one day as can be made watertight in the same day.

Daily Protection: Coordinate installation of roofing so insulation and other components of roofing system not permanently exposed are not subjected to precipitation or left uncovered at the end of the workday or when rain is forecast.

Retain one of two "Hazardous Materials" paragraphs below or delete if no hazardous materials. Asbestos-containing materials may be encountered during reroofing. Coordinate statements with the General and Supplementary Conditions.

Hazardous Materials: It is not expected that hazardous materials such as asbestos-containing materials will be encountered in the Work.

Hazardous materials will be removed by Owner before start of the Work. Existing roof will be left no less watertight than before removal.

If materials suspected of containing hazardous materials are encountered, do not disturb; immediately notify Owner's Consultant and Owner.

Use the first subparagraph when Owner will arrange for discovered asbestos containing material (ACM) to be removed under a separate contract. Use the second subparagraph when the Contractor will be required to remove ACM (by adjustment to the contract sum). Retain requirements for Contractor to be licensed accordingly, and for legal disposal of ACM.

Hazardous materials will be removed by Owner under a separate contract.

PRODUCTS

TEMPORARY ROOFING MATERIALS

Design and selection of materials for temporary roofing are responsibilities of Contractor.

TEMPORARY ROOF DRAINAGE

Design and selection of materials for temporary roof drainage are responsibilities of the Contractor.

EXECUTION

PREPARATION, GENERAL

Seal or isolate windows that may be exposed to airborne substances created in removal of existing materials.

Shut off rooftop utilities and service piping before beginning the Work.

Test existing roof drains to verify that they are not blocked or restricted.

Immediately notify Owner's Consultant of any blockages or restrictions.

Depending on duration of equipment shutdown and occupancy of building, revise first paragraph below if necessary to specify special work hours (for example, nights or weekends) for portions of roof near air intakes. If necessary to deactivate all or a portion of fire-detection system, revise paragraph to add special measures, such as a fire watch.

Coordinate with Owner to shut down air-intake equipment in the vicinity of the Work.

Cover air-intake louvers before proceeding with reroofing work that could affect indoor air quality or activate smoke detectors in the ductwork.

Pollution Control: Comply with environmental regulations of authorities having jurisdiction. Limit spread of dust and debris.

Remove and transport debris in a manner that will prevent spillage on adjacent surfaces and areas.

Remove debris from building roof by chute, hoist, or other device that will convey debris to grade level.

Temporary Weather Protection: During removal operations, have sufficient and suitable materials on-site to facilitate rapid installation of temporary protection in the event of unexpected rain.

Roof Drain Protection: Maintain roof drains in functioning condition to ensure roof drainage at end of each workday.

If roof drains are temporarily blocked or unserviceable due to roofing system removal or partial installation of new membrane roofing system, provide alternative drainage method to remove water and eliminate ponding. Do not permit water to enter into or under existing membrane roofing system components that are to remain.

Prevent debris from entering or blocking roof drains and conductors.

Use roof-drain plugs specifically designed for this purpose.

Remove roof-drain plugs at end of each workday, when no work is taking place, or when rain is forecast.

If roof drains are temporarily blocked or unserviceable due to roofing system removal or partial installation of new membrane roofing system, provide alternative drainage method to remove water and eliminate ponding.

Do not permit water to enter into or under existing membrane roofing system components that are to remain.

ROOF TEAR-OFF

Retain and edit applicable paragraphs from below.

Retain option in first paragraph below if Owner intends to authorize each day's work. Specify restrictions or limitations that will be placed on Installer to limit unscheduled delays.

Notify Owner each day of extent of roof tear-off proposed for that day.

Lower removed roofing materials to ground and onto lower roof levels, using dust-tight chutes or other acceptable means of removing materials from roof areas.

Roof Drainage: Remove roof drainage items indicated for removal.

Roof Tear-Off: Remove existing roofing membrane and other membrane roofing system components down to the deck.

Remove roof insulation.

Bitumen and felts that are firmly bonded to concrete decks are permitted to remain if felts are dry. Remove unadhered bitumen and felts and wet felts.

Remove fasteners from deck or cut fasteners off slightly above deck surface.

Edit the following to describe reuse or replacement of perimeter metal systems. Retain subparagraph and applicable option when replacing edge metals with new formed- or manufactured-systems.

Roof Edge Specialties: Replace existing perimeter metal systems with new perimeter metal systems.

New perimeter metal systems (fascia and coping) are specified in Division 07 Section "Roof Specialties."

Inspect wood blocking, curbs, and nailers for deterioration and damage.

Replace existing wood components that exhibit signs of deterioration or other conditions detrimental to securement of roofing system components, including roof edge flashings.

Reuse of Existing Wood Nailers: Permitted where type, size and securement are in accordance with Factory Mutual Loss Prevention Data Bulletin 1-49; and existing wood nailers exhibit no signs of deterioration or other conditions detrimental to securement of new roofing system in conformance with specified requirements.

DECK PREPARATION

Retain this article for roof tear-off or partial roof tear-off.

Inspect deck after tear-off of membrane roofing system.

Verify that deck is sound and dry.

If broken or loose fasteners that secure deck panels to one another or to structure are observed or if deck appears or feels inadequately attached, immediately notify Owner's Consultant. Do not proceed with installation until directed by Owner's Consultant.

Unsuitable Deck: If deck surface is not suitable for receiving new roofing or if structural integrity of deck is suspect, immediately notify Owner. Do not proceed with installation until directed by Owner.

EQUIPMENT REMOVAL AND REINSTALLATION

General: Remove, store, protect and reinstall rooftop equipment as required to accommodate roof tear-off and subsequent roofing work.

Raise roof curbs, equipment mountings and other roof penetration flashings as required to accommodate additional insulation thickness and maintain base flashing height of not less than 8 inches (200 mm), unless otherwise indicated.

Provide wood assemblies and additional support with miscellaneous galvanized steel angles, as required to rebuild or raise existing roof curbs.

Extend vent and soil stacks and other roof penetrations, using matching materials, as required to accommodate additional insulation thickness.

Extend existing ductwork inside existing roof curbs to accommodate extension of curb.

Use materials matching existing ductwork; minimum of 20 ga. (0.9 mm) galvanized duct with Pittsburgh folded seam slip joints-typical.

Rooftop Equipment, Electrical: Engage a qualified electrician to perform electrical disconnection and reconnection.

Disconnect, reroute, extend and reconnect existing power feeders and control circuits (conduit and wiring) feeding the existing roof mounted equipment which is indicated to be raised and/or relocated to a new elevation/location and as required by the Contract.

Provide weatherproof exterior junction boxes, when required.

Make connections to mechanical equipment by using a maximum 18-inch (450-mm) length of liquid-tight flexible steel conduit.

Rigid connections to mechanical equipment are not permitted.

Relocate and reconnect existing disconnect switches presently installed on existing roof mounted equipment indicated to be raised and/or relocated.

Prevent discharge of refrigerant. Verify that refrigerant has been properly recovered from equipment to be removed.

Retain the following when existing roof top equipment is to be removed and NOT reinstalled.

Remove and dispose of designated abandoned equipment. Infill openings in deck with matching materials. Infill roofing system with materials of same type as existing, adjacent roofing system.

BASE FLASHING REMOVAL

Remove existing base flashings around parapets, curbs, walls, and penetrations.

Clean substrates of contaminants, such as asphalt, sheet materials, dirt, and debris.

Do not damage metal counterflashings that are to remain.

Replace metal counterflashings damaged during removal with counterflashings of same metal, weight or thickness, and finish.

DISPOSAL

Collect demolished materials and place in containers. Promptly dispose of demolished materials. Do not allow demolished materials to accumulate on-site.

Storage or sale of demolished items or materials on-site is not permitted.

Transport and legally dispose of demolished materials off Owner's property.

CLEANING

Clean adjacent structures and improvements of dust, dirt, and debris caused by preparation for re-roofing operations. Return adjacent areas to condition existing before operations began.

END OF SECTION 070150