07591-Preparation for Reroofing 20090227 .doc

Ellington JRB Houston, Texas

PREPERATION FOR REROOFING

PART 1 GENERAL

1.1

SECTION INCLUDES

A. Membrane reroofing preparation for roof tear-off, temporary roofing membrane, removal of base flashings, installation of vented base at lightweight concrete decks, and protection of existing roofing system as it is installed 1.2

RELATED SECTIONS

A. Section 05440 – Retrofit Roof Framing System

B. Section 06100 - Rough Carpentry:

C. Section 07410 – Standing Seam Roof Panels D. Section 07536 – Modified Bitumen Roof Membrane E. Section 07550 – Coal Tar Modified Bituminous Membrane Roofing F. Section 07590 - Preparation for Reroofing.

G. Section 07220 - Roof and Deck Insulation.

H. Section 07600 “Flashing and Sheet Metal”.

1.3

SUBMITTALS

A. Product Data: Provide manufacturer’s technical product data for each type of roofing product specified. Include data substantiating that materials comply with specified requirements.

B. 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.

C. Fastener pull-out test report.

D. Photographs or Videotape: Show existing conditions of adjoining construction and site improvements, including exterior and interior finish surfaces, that might be misconstrued as having been damaged by reroofing operations. Submit before Work begins.

1.3

PRE-INSTALLATION CONFERENCE

A. Regulatory Requirements: Comply with governing EPA notification regulations before beginning membrane roofing removal. Comply with hauling and disposal regulations of authorities having jurisdiction

B. Preliminary Reroofing Conference: Convene a pre-roofing conference approximately two (2) weeks before scheduled commencement of reproofing installation and associated work.

C. Require attendance of installer of each component of associated work, installers of deck or substrate construction to receive roofing work, installers of rooftop units and other work in and around roofing which must precede or follow roofing work (including mechanical work if any), Contracting Officer, Owner, roofing system manufacturer’s representative, and other representatives directly concerned with performance of the Work, including (where applicable) Owner’s insurers, testing agencies and governing authorities.

D. Objectives of conference to include:

1. Review foreseeable methods and procedures related to reroofing work.

2. Tour representative areas of roofing substrates (decks), inspect and discuss condition of substrate, roof drains, curbs, penetrations and other preparatory work performed by others.

3. Review structural loading limitations of deck and inspect deck for loss of flatness and for required attachment.

4. Review reroofing system requirements (drawings, specifications and other contract documents).

5. Review required submittals both completed and yet to be completed.

6. Review and finalize construction schedule related to reroofing work and verify availability of materials, installer’s personnel, equipment and facilities needed to make progress and avoid delays.

7. Review required inspection, testing, certifying and material usage accounting procedures.

8. Review weather and forecasted weather conditions and procedures for coping with unfavorable conditions, including possibility of temporary roofing (if not mandatory requirement).

9. Record discussion of conference including decisions and agreements (or disagreements) reached and furnish copy of record to each party attending. If substantial disagreements exist at conclusion of conference, determine how disagreements will be resolved and set date for reconvening conference.

10. Review notification procedures for weather or non-working days.

1.6

PROJECT CONDITIONS

A. 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 [72] hours' notice of activities that may affect Owner's operations

1. 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 if desired.

2. 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 prior to proceeding with work over the impaired deck area.

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

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

D. Owner assumes no responsibility for condition of areas to be reroofed.

1. Conditions existing at time of inspection for bidding will be maintained by Owner as far as practical.

E. Weather Condition Limitations: Do not apply roofing membrane during inclement weather or when a 40% chance of precipitation is expected.

1.7

WARRANTY

A. Upon completion of installation, and acceptance by the Owner and Contracting Officer, the manufacturer will supply to the Owner the appropriate warranty.

B. Installer will submit a minimum of a [two (2)] year warranty to the membrane manufacturer with a copy directly to Owner.

C. Membrane manufacturer will provide an annual inspection for the life of the warranty.

PART 2 PRODUCTS

2.1

TEMPORARY ROOFING MATERIALS

A. Sheathing Paper: Red-rosin type, minimum 3 lb/100 sq. ft. (0.16 kg/sq. m).

B. Asphalt Roofing Mastic: V.O.C. compliant, ASTM D-2822, Type II.

C. Glass-Fiber Felts: ASTM D 2178, Type IV, asphalt-impregnated, glass-fiber felt. (temporary roof at Vehicle Maintenance Facility).

D. Asphalt Primer: ASTM D 41.

E. Roofing Asphalt: ASTM D 312, Type IV.

2.2

AUXILIARY REROOFING MATERIALS

A. General: Auxiliary reroofing preparation materials recommended by roofing system manufacturer for intended use and compatible with components of [existing and ] new membrane roofing system.

B. Base Sheet Fasteners: Capped head, factory-coated steel fasteners, listed in FM Approval Guide. ES FM-90 or Olympic 1.75" CR-Base Sheet Fasteners.

C. Base Sheet: ASTM D 4601, Type II, fiberglass vented base with channel indentation on one side. (Medial Training facility-Dining Hall area only)

PART 3 EXECUTION

3.1

PREPARATION

A. Protect existing membrane roofing system that is indicated not to be reroofed.

1. Existing Warranties: Remove, replace, patch, and repair materials and surfaces cut or damaged during reroofing, by methods and with materials so as not to void existing roofing system warranty. Notify warrantor before proceeding.

2. Limit traffic and material storage to areas of existing roofing membrane that have been protected

3. Maintain temporary protection and leave in place until replacement roofing has been completed.

B. 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.

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

D. Maintain roof drains in functioning condition to ensure roof drainage at end of each workday. 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.

1. If roof drains will be 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.

E. Verify that rooftop utilities and service piping have been shut off before commencing Work F. Verify that openings, curbs, pipes, conduit, sleeves, ducts, and other items which penetrate the roof are set solidly, and that [wood cant strips] [wood nailing strips] [and reglets] are set in place.

3.2 MATERIAL REMOVAL (Medical Training facility-Dining Hall area and the entire Vehicle Maintenance Facility) A. Remove all membrane, cant strips, insulation, cant strips, base flashings and items shown on the drawings. The complete removal of all nails to leave a smooth even surface for re-roofing is required.

B. Under certain conditions it will be necessary and desirable to incorporate on or more of the following methods for removal of dirt, silt, gravel, debris, roof membrane and insulation from the roof surface in order to preserve the ecology, eliminate unsightly conditions and protect building:

1. Roof vacuum system.

2. Crane and hopper with dump truck system.

3. Enclosed shuts with protective shrouds on building and ground surfaces.

C. All debris dumped from the roof shall be transported from the roof via chutes into dumpsters or trucks, and this debris shall, be removed from the premises when vehicles are full. No debris shall be transported from the area being worked over an existing finished roof without and underlayment of 3/4" plywood.

D. All roof equipment not in use or left filled will be parked on the column lines on 3/4" plywood.

E. Contractor shall provide tie-ins at the end of each days work. Area of tie-in shall be spudded clean of all existing gravel.

3.3

DECK PREPARATION

A. Inspect deck after tear-off of membrane roofing system.

1. Verify that substrate is visibly dry and free of moisture. Test for capillary moisture by plastic sheet method according to ASTM D 4263 or by pouring 1 pint (0.5 L) of hot roofing asphalt on deck at start of each day's work and at start of each roof area or plane. Do not proceed with roofing work if moisture condenses under the plastic sheet or if asphalt test sample foams or can be easily and cleanly stripped after cooling.

B. 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 Contracting Officer. Do not proceed with installation until directed by Contracting Officer.

C. If deck surface is not suitable for receiving new roofing, or if structural integrity of deck is suspect, immediately notify Contracting Officer. Do not proceed with installation until directed by Contracting Officer.

3.4 TEMPORARY ROOFING MEMBRANE ( Entire Vehicle Maintenance Except Canopies) A. Install approved temporary roofing membrane over insulation specified in Section 07220 at areas to receive retrofit roof framing system.

B. Install temporary roofing membrane over area to be reroofed. Install 2 glass-fiber felts lapping each sheet 19 inches (483 mm) over preceding sheet. Embed glass-fiber felt in a solid mopping of hot roofing asphalt applied within equiviscous temperature range. Glaze-coat completed surface with hot roofing asphalt.

C. Prepare the temporary roof to receive new roofing membrane [according to approved temporary roofing membrane proposal] [by patching and repairing temporary roofing membrane]. Restore temporary roofing membrane to watertight condition. Obtain approval for temporary roof substrate from membrane manufacturer and Contracting Officer prior to installation of new roof.

3.6 VENTED BASE SHEET APPLICATION (At rear Dining Hall-Medical Training Facility)

A. Over all lightweight insulating concrete deck areas, roll out the vented base sheet over the surface, channel side down, smooth side up. Lap subsequent sheets 4" over the preceding one. Mechanically attach the vented base sheet laps at 7" centers, and down the longitudinal center of each sheet nail two rows of nails with rows spaced approximately 11" apart and nails staggered on approximately 7" centers. Extend over and up wood blocking and tack into place.

B. Increase fastening pattern by 50% in the 12’ perimeter and by 100% in the 16’ corners.

3.7 FIELD QUALITY CONTROL

A. Perform field inspection and [and testing] as required [under provisions of Section 01410.

B. Correct defects or irregularities discovered during field inspection.

C. Require attendance of roofing [and insulation] materials manufacturers’ representatives at site during installation of the roofing system.

3.10 CLEANING

A. Remove bitumen adhesive drippings from all walls, windows, floors, ladders and finished surfaces.

B. In areas where finished surfaces are soiled by asphalt or any other sources of soiling caused by work of this section, consult manufacturer of surfaces for cleaning instructions and conform to their instructions.

C. Repair or replace defaced or disfigured finishes caused by work of this section.

3.11

FINAL INSPECTION

A. At completion of roofing installation and associated work, meet with Contractor, Contracting Officer, installer, installer of associated work, Owner, roofing system manufacturer’s representative, and other representatives directly concerned with performance of roofing system.

B. Walk roof surface areas of the building, inspect perimeter building edges as well as flashing of roof penetrations, walls, curbs and other equipment. List all items requiring correction or completion and furnish copy of list to each party in attendance.

C. The roofing system manufacturer reserves the right to request a thermographic scan of the roof during final inspection to determine if any damp or wet materials have been installed. The thermographic scan shall be provided by the Contractor.

D. If core cuts verify the presence of damp or wet materials, the [Roofing] Contractor shall be required to replace the damaged areas at his own expense.

E. Repair or replace deteriorated or defective work found at time above inspection as required to a produce an installation which is free of damage and deterioration at time of Substantial Completion and according to warranty requirements.

F. Notify the Contracting Officer upon completion of corrections.

G. Following the final inspection, provide written notice of acceptance of the installation from the roofing system manufacturer.

END OF SECTION

Preparation for Reroofing

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