BID#1973?MDUSD 2026?Roofing Project - Holbrook Language Academy and Valle Verde Elementary School Addendum 1

PURCHASING & WAREHOUSE DEPARTMENT
2326 Bisso Lane, Concord, California 94520
BID #1973
2026 Roofing Project -
Holbrook and Valle Verde
Elementary Schools
FOR
MT. DIABLO UNIFIED SCHOOL DISTRICT
ADDENDUM #1

DOCUMENT 00 91 13
ADDENDA
03/10/2026
NOTICE TO ALL BIDDERS: THE FOLLOWING MODIFICATIONS, ADDITIONS, DELETIONS, CLARIFICATIONS
AND/OR INFORMATION ARE HEREBY MADE PART OF THE CONTRACT DOCUMENTS. ADDENDUM MUST
BE ACKNOWLEGDED AS PART OF THE BIF FORM.
(1) CHANGES TO TECHNFICAL SPECIFICATIONS (attached)
(a) 07.55.00 - Modified Bituminous Roofing - Removed and replaced
(2) BID QUESTIONS (RFI's)
(a) What is the engineer's estimate for this project?
(i) $4,400,000.00
(b) What is the warranty/Maintenance period?
(i) 5-year craftsmanship warranty as outlined in Article 1 of the technical spec section,
07.55.00-Modified Bituminous Roofing.
(c) Do we need to prequalify through Quality Bidders if we are submitting a bid as a C-39
roofing Contractor?
(i) Per Instruction to Bidders; all prime bidders are required to prequalify prior to submitting
a bid to MDUSD.
Mt. Diablo Unified School District Addenda
ADDENDUM #1 DOCUMENT 00 91 13 1

2026 Roof Package #2 - Valle Verde ES and Holbrook Language Academy
Mt. Diablo Unified School District
SECTION 07550
MODIFIED BITUMINOUS MEMBRANE ROOFING
PART 1 GENERAL
1.1 SECTION INCLUDES
A. Includes all labor, non-owner supplied materials, and equipment to install a modified bitumen
roof system over the properly prepared substrate.
B. Includes removal and disposal of existing roofing system(s), insulation board, gutters,
downspouts (schedule 40 to remain), flashings, counter flashings, sheet metal items,
copings, expansion joints, etc. for a complete prepared roof surface to receive the new
roofing system.
C. Includes a new hot applied 2-ply asphalt roofing system with all accessories as needed for a
complete warrantable roofing system.
D. Includes testing of all drains and downspouts before construction and after construction to
ensure proper drain performance.
1.2 RELATED SECTIONS
A. Section 01640 - Owner Furnished Material
B. Section 07220 - Roof Deck Insulation
C. Section 07620 - Sheet Metal Flashing and Trim
1.3 REFERENCES
A. ASTM D 41 - Standard Specification for Asphalt Primer Used in Roofing, Dampproofing, and
Waterproofing.
B. ASTM D 312 - Standard Specification for Asphalt used in Roofing.
C. ASTM D 451 - Standard Test Method for Sieve Analysis of Granular Mineral Surfacing for
Asphalt Roofing Products.
D. ASTM D 1079 Standard Terminology Relating to Roofing, Waterproofing and Bituminous
Materials.
E. ASTM D 1863 Standard Specification for Mineral Aggregate Used as a Protective Coating
for Roofing.
F. ASTM D 2178 Standard Specification for Asphalt Glass Felt Used in Roofing and
Waterproofing.
G. ASTM D 2822 Standard Specification for Asphalt Roof Cement.
H. ASTM D 4601 Standard Specification for Asphalt Coated Glass Fiber Base Sheet Used in
Roofing.
I. ASTM D 5147 Standard Test Method for Sampling and Testing Modified Bituminous Sheet
Materials.
J. ASTM D 6162 Standard Specification for Styrene Butadiene Styrene (SBS) Modified
07550-1 ADDENDUM #1

2026 Roof Package #2 - Valle Verde ES and Holbrook Language Academy
Mt. Diablo Unified School District
Bituminous Sheet Materials Using a Combination of Polyester and Glass Fiber
Reinforcements.
K. ASTM E 108 - Standard Test Methods for Fire Test of Roof Coverings
L. Factory Mutual Research (FM): Roof Assembly Classifications.
M. National Roofing Contractors Association (NRCA): Roofing and Waterproofing Manual.
N. Sheet Metal and Air Conditioning Contractors National Association, Inc. (SMACNA) -
Architectural Sheet Metal Manual.
O. Underwriters Laboratories, Inc. (UL): Fire Hazard Classifications.
P. Warnock Hersey (WH): Fire Hazard Classifications.
Q. ANSI-SPRI ES-1 Wind Design Standard for Edge Systems used with Low Slope Roofing
Systems.
R. ASCE 7, Minimum Design Loads for Buildings and Other Structures
S. UL - Fire Resistance Directory.
T. FM Approvals - Roof Coverings and/or RoofNav assembly database.
U. California Title 24 Energy Efficient Standards.
1.4 DESIGN / PERFORMANCE REQUIREMENTS
A. Perform work in accordance with all federal, state and local codes.
B. Exterior Fire Test Exposure: Roof system shall achieve a UL, FM or WH Class rating for roof
slopes indicated on the Drawings as follows:
1. Factory Mutual Class A Rating.
2. Underwriters Laboratory Class A Rating.
3. Warnock Hersey Class A Rating.
C. Design Requirements:
1. Uniform Wind Uplift Load Capacity
a. Installed roof system shall withstand negative (uplift) design wind loading
pressures complying with the following criteria.
1) Design Code: ASCE 7, Method 2 for Components and Cladding.
2) Importance Category:
a) III.
3) Importance Factor of:
a) 1.0
4) Wind Speed: 115 mph
5) Ultimate Pullout Value: 364 pounds per each of the fastener
6) Exposure Category:
a) B.
7) Roof Pitch: 0.5 :12.
8) Roof Area Design Uplift Pressure:
a) Zone 1 - Field of roof 14.3 psf
b) Zone 2 - Eaves, ridges, hips and rakes 24 psf
c) Zone 3 - Corners 36 psf
2. Live Load: 20 psf, or not to exceed original building design.
3. Dead Load:
a. Installation of new roofing materials shall not exceed the dead load capacity of
07550-2 ADDENDUM #1

2026 Roof Package #2 - Valle Verde ES and Holbrook Language Academy
Mt. Diablo Unified School District
the existing roof structure.
D. Energy Star: Roof System shall comply with the initial and aged reflectivity required by the
U.S. Federal Government's Energy Star program.
E. LEED: Roof system shall meet the reflectivity and emissivity criteria to qualify for one point
under the LEED credit category, Credit 7.2, Landscape & Exterior Design to Reduce Heat
Island - Roof.
F. Roof System membranes containing recycled or bio-based materials shall be third party
certified through UL Environment.
G. Roof system shall have been tested in compliance with the following codes and test
requirements:
1. Cool Roof Rating Council:
a. CRRC Directory CRRC 077-0028
2. International Code Council Evaluation Service (ICC-ES):
a. Membrane Systems
1) ESR
3. Underwriters Laboratories:
a. Certification TGFU.R
4. Warnock Hersey
a. ITS Directory of Listed Products
5. FM Approvals:
a. RoofNav Website
1.5 SUBMITTALS
A. Submit under provisions of Section 01300.
B. Product Data: Manufacturer's data sheets on each product to be used, including:
1. Preparation instructions and recommendations.
2. Storage and handling requirements and recommendations.
3. Installation instructions.
C. Shop Drawings: Submit shop drawings including installation details of roofing, flashing,
fastening, insulation and vapor barrier, including notation of roof slopes and fastening
patterns of insulation and base modified bitumen membrane, prior to job start.
D. Design Pressure Calculations: Submit design pressure calculations for the roof area in
accordance with ASCE 7 and local Building Code requirements. Include a roof system
attachment analysis report, certifying the system's compliance with applicable wind load
requirements before Work begins. Report shall be signed and sealed by a Professional
Engineer registered in the State of the Project who has provided roof system attachment
analysis for not less than 5 consecutive years.
E. LEED Submittals: Provide documentation of how the requirements of Credit will be met:
1. List of proposed materials with recycled content. Indicate post-consumer recycled
content and pre-consumer recycled content for each product having recycled content.
2. Product data and certification letter indicating percentages by weight of post-
consumer and pre-consumer recycled content for products having recycled content.
3. Product reflectivity and emissivity criteria to qualify for one point under the LEED
credit category, Credit 7.2, Landscape & Exterior Design to Reduce Heat Island -
Roof.
F. Recycled or Bio-Based Materials: Provide third party certification through UL Environment of
roof System membranes containing recycled or bio based materials
07550-3 ADDENDUM #1

2026 Roof Package #2 - Valle Verde ES and Holbrook Language Academy
Mt. Diablo Unified School District
G. Verification Samples: For each modified bituminous membrane ply product specified, two
samples, minimum size 6 inches (150 mm) square, representing actual product, color, and
patterns.
H. Manufacturer's Contractor Authorization: Provide written authorization acknowledgement
from the roofing system manufacturer that the applicator is currently authorized to install the
specified roof system and able to provide the specified warranty. Manufacturer's
acknowledgement letter must be dated within one (1) year of the bid date.
I. Sample Warranty: Provide an unexecuted copy of the warranty specified for this project
clearly stating the terms required of the owner, contractor, and manufacturer.
J. Manufacturer's Certificates: Provide to certify products meet or exceed specified
requirements.
K. Test Reports: Submit test reports, prepared by an independent testing agency, for all
modified bituminous sheet roofing, indicating compliance with ASTM D5147.
L. Manufacturer's Fire Compliance Certificate: Certify that the roof system furnished is
approved by Factory Mutual (FM), Underwriters Laboratories (UL), Warnock Hersey (WH) or
approved third party testing facility in accordance with ASTM E108, Class A for external fire
and meets local or nationally recognized building codes.
M. Closeout Submittals: Provide manufacturer's maintenance instructions that include
recommendations for periodic inspection and maintenance of all completed roofing work.
Provide product warranty executed by the manufacturer. Assist Owner in preparation and
submittal of roof installation acceptance certification as may be necessary in connection with
fire and extended coverage insurance on roofing and associated work.
1.6 QUALITY ASSURANCE
A. Perform Work in accordance with NRCA Roofing and Waterproofing Manual.
B. Manufacturer Qualifications: Company specializing in manufacturing products specified with
documented ISO 9001 certification and minimum of twelve years of documented experience
and must not have been in Chapter 11 bankruptcy during the last five years.
C. Installer Qualifications: Company specializing in performing Work of this section with
minimum five years documented experience and a certified Pre-Approved Garland
Contractor.
D. Installer's Field Supervision: Maintain a full-time Supervisor/Foreman on job site during all
phases of roofing work while roofing work is in progress.
E. Product Certification: Provide manufacturer's certification that materials are manufactured in
the United States and conform to requirements specified herein, are chemically and
physically compatible with each other, and are suitable for inclusion within the total roof
system specified herein.
F. Source Limitations: Obtain all components of roof system from a single manufacturer.
Secondary products that are required shall be recommended and approved in writing by the
roofing system Manufacturer. Upon request of the Architect or Owner, submit Manufacturer's
written approval of secondary components in list form, signed by an authorized agent of the
Manufacturer.
1.7 PRE-INSTALLATION MEETINGS
A. Convene minimum two weeks prior to commencing Work of this section.
07550-4 ADDENDUM #1

2026 Roof Package #2 - Valle Verde ES and Holbrook Language Academy
Mt. Diablo Unified School District
B. Review installation procedures and coordination required with related Work.
C. Inspect and make notes of job conditions prior to installation:
1. Record minutes of the conference and provide copies to all parties present.
2. Identify all outstanding issues in writing designating the responsible party for follow-up
action and the timetable for completion.
3. Installation of roofing system shall not begin until all outstanding issues are resolved
to the satisfaction of the Owner and Architect.
1.8 DELIVERY, STORAGE, AND HANDLING
A. Deliver and store products in manufacturer's unopened packaging with labels intact until
ready for installation.
B. Store all roofing materials in a dry place, on pallets or raised platforms, out of direct
exposure to the elements until time of application. Store materials at least 4 inches above
ground level and covered with "breathable" tarpaulins.
C. Stored in accordance with the instructions of the manufacturer prior to their application or
installation. Store roll goods on end on a clean flat surface except store KEE-Stone FB 60
rolls flat on a clean flat surface. No wet or damaged materials will be used in the application.
D. Store at room temperature wherever possible, until immediately prior to installing the roll.
During winter, store materials in a heated location with a 50 degree F (10 degree C)
minimum temperature, removed only as needed for immediate use. Keep materials away
from open flame or welding sparks.
E. Avoid stockpiling of materials on roofs without first obtaining acceptance from the
Architect/Engineer.
1.9 COORDINATION
A. Coordinate Work with installing associated metal flashings as work of this section proceeds.
1.10 PROJECT CONDITIONS
A. Maintain environmental conditions (temperature, humidity, and ventilation) within limits
recommended by manufacturer for optimum results. Do not install products under
environmental conditions outside manufacturer's absolute limits.
1.11 WARRANTY
A. Upon completion of the work, provide the Manufacturer's written and signed NDL Warranty,
warranting that, if a leak develops in the roof during the term of this warranty, due either to
defective material or defective workmanship by the installing contractor, the manufacturer
shall provide the Owner, at the Manufacturer's expense, with the labor and material
necessary to return the defective area to a watertight condition. Warranty shall be solely
provided by the roof system manufacturer and must cover the calculated wind speed. No 3rd
party warranties or insurance riders will be accepted.
1. Warranty Period:
a. 30 years from date of acceptance.
B. Installer is to guarantee all work against defects in materials and workmanship for a period
indicated following final acceptance of the Work.
1. Warranty Period:
a. 5 years from date of acceptance.
PART 2 PRODUCTS
07550-5 ADDENDUM #1

2026 Roof Package #2 - Valle Verde ES and Holbrook Language Academy
Mt. Diablo Unified School District
2.1 MANUFACTURERS
A. Acceptable Manufacturer: The Garland Company, Inc.; 3800 E. 91st St., Cleveland, OH
44105. Local Representative: Doug Clark Phone: (925) 784-6701. dclark@garlandind.com
Web Site: www.garlandco.com.
B. Requests for substitutions will not be considered for this project as MDUSD is supplying the
material to complete the project through CMAS.
C. The Products specified are intended and the Standard of Quality for the products required
for this project. If other products are proposed the bidder must disclose in the bid the
manufacturer and the products that they intend to use on the Project. If no manufacturer
and products are listed, the bid may be accepted only with the use of products specified.
1. Bidder will not be allowed to change materials after the bid opening date.
2. If alternate products are included in the bid, the products must be equal to or exceed
the products specified. Supporting technical data shall be submitted to the Architect/
Owner for approval prior to acceptance.
3. In making a request for substitution, the Bidder/Roofing Contractor represents that it
has:
a. Personally investigated the proposed product or method, and determined that it
is equal or superior in all respects to that specified.
b. Will provide the same guarantee for substitution as for the product and method
specified.
c. Will coordinate installation of accepted substitution in work, making such
changes as may be required for work to be completed in all respects.
d. Will waive all claims for additional cost related to substitution, which
consequently become apparent.
e. Cost data is complete and includes all related cost under his/her contract or
other contracts, which may be affected by the substitution.
f. Will reimburse the Owner for all redesign cost by the Architect for
accommodation of the substitution.
4. Architect/ Owner reserves the right to be the final authority on the acceptance or
rejection of any or all bids, proposed alternate roofing systems or materials that has
met ALL specified requirement criteria.
5. Failure to submit substitution package, or any portion thereof requested, will result in
immediate disqualification and consideration for that particular contractors request for
manufacturer substitution.
2.2 HOT APPLIED 2-PLY ROOF SYSTEM
A. Rosin Sheet: One ply of mechanically attached to the prepared substrate.
1. Red Rosin Paper:
B. Insulation: As specified in Section 07220
1. One layer of six side primed 12" woodfiber insulation board is to be installed with
mechanical fasteners per ASCE 7.
C. Base (Ply) Sheet: One ply bonded to the prepared substrate with Interply Adhesive:
1. Flexbase Plus 80:
D. Modified Cap Sheet: One ply bonded to the prepared substrate with Interply Adhesive:
1. StressPly Plus FR Mineral:
E. Interply Adhesive:
1. Garlastic KM Plus: 20 lbs per square
F. Flashing Base (Ply): One ply bonded to the prepared substrate with Interply Adhesive:
07550-6 ADDENDUM #1

2026 Roof Package #2 - Valle Verde ES and Holbrook Language Academy
Mt. Diablo Unified School District
1. Flexbase Plus 80:
G. Flashing Cap Sheet: One ply bonded to the prepared substrate with Interply Adhesive:
1. StressPly Plus FR Mineral:
H. Flashing Ply Adhesive:
1. Garlastic KM Plus: 20 lbs per square
I. Surfacing:
1. Reflective coating: Pyramic Plus LO Coating: Two coats of 1.5 gallon per square (3
gal total per square)
2. Flood Coat: Green-Lock Plus Membrane Adhesive: 4 gallons per square
a. Aggregate provided by Wise Product Group: Title 24 approved 3/8" gravel at
400 lbs per square
2.3 ACCESSORIES:
A. Roof Insulation Base Layer(s): Provide roof insulation as specified in accordance with
Section 07220.
B. Roof Insulation Top Layer: Provide one layer of 12" six side primed Blue Ridge Structodek
High Density Fiberboard Roof Insulation. ASTM C 208, Type II.
C. Protective sheet: Red Rosin Paper; Install layer rosin sheet shingled uniformly to achieve
one ply over the entire prepared substrate. Shingle in direction of slope of roof to shed water
on each area of roof.
1. Red Rosin Paper by WR Meadows
a. Weight - 12 lb./roll
b. Size - 500 square feet p/roll
c. 36" wide by 167' long
D. Nails and Fasteners: Non-ferrous metal or galvanized steel, except that hard copper nails
shall be used with copper; aluminum or stainless steel nails shall be used with aluminum;
and stainless steel nails shall be used with stainless steel, Fasteners shall be self-clinching
type of penetrating type as recommended by the deck manufacturer. Fasten nails and
fasteners flush-driven through flat metal discs not less than 1 inch (25 mm) diameter. Omit
metal discs when one-piece composite nails or fasteners with heads not less than 1 inch (25
mm) diameter are used.
E. Urethane Sealant Hybrid - Tuff-Stuff MS: One part, non-sag sealant as approved and
furnished by the membrane manufacturer for moving joints.
1. Tensile Strength, ASTM D 412: 250 psi
2. Elongation, ASTM D 412: 450%
3. Hardness, Shore A ASTM C 920: 35
4. Adhesion-in-Peel, ASTM C 92: 30 pli
F. Sealant - Green-Lock Structural Adhesive: Single component, 100% solids structural
adhesive as furnished and recommended by the membrane manufacturer.
1. Elongation, ASTM D 412: 300%
2. Hardness, Shore A, ASTM C 920: 50
3. Shear Strength, ASTM D 1002: 300 psi
G. Butyl Tape: 100% solids, asbestos free and compressive tape designed to seal as
recommended and furnished by the membrane manufacturer.
H. Glass Fiber Cant - Glass Cant: Continuous triangular cross Section made of inorganic
fibrous glass used as a cant strip as recommended and furnished by the membrane
07550-7 ADDENDUM #1

2026 Roof Package #2 - Valle Verde ES and Holbrook Language Academy
Mt. Diablo Unified School District
manufacturer.
I. Mastic: Flashing Bond
2.4 EDGE TREATMENT AND ROOF PENETRATION FLASHINGS
A. Pre-Manufactured Edge Metal Finishes:
1. Exposed and unexposed surfaces for mill finish flashing, fascia, and coping cap, as
shipped from the mill
2. Exposed surfaces for coated panels:
a. Steel Finishes: fluorocarbon finish. Epoxy primer baked both sides, .2-.25 mils
thickness as approved by finish coat manufacturer.
Weathering finish as referred by National Coil Coaters Association (NCCA).
Provided with the following properties.
1) Pencil Hardness: ASTM D3363, HB-H / NCCA II-2.
2) Bend: ASTM D-4145, O-T / NCCA II-19
3) Cross-Hatch Adhesion: ASTM D3359, no loss of adhesion
4) Gloss (60 deg. angle): ASTM D523, 25+/-5%
5) Reverse Bend: ASTM D2794, no cracking or loss of adhesion
6) Nominal Thickness: ASTM D1005
a) Primer: 0.2 mils
b) Topcoat, 0.7 mils min
c) Clear Coat (optional, only used with 22 ga. steel) 0.3 mils
7) Color: Provide as specified. (Subject to minimum quantities)
B. Vents and Breathers: Heavy gauge aluminum and fully insulated vent that allows moisture
and air to escape but not enter the roof system as recommended and furnished by the
membrane manufacturer.
C. Pitch pans, Rain Collar 24 gauge stainless or 20oz (567gram) copper. All joints should be
welded/soldered watertight. See details for design.
D. Drain Flashings: Green-Weld PVB per manufacturers guidelines.
E. Plumbing stacks: Green-Weld PVB per manufacturers guidelines.
F. Liquid Flashing - Tuff-Flash: An asphaltic-polyurethane, low odor, liquid flashing material
designed for specialized details unable to be waterproofed with typical modified membrane
flashings.
1. Tensile Strength, ASTM D 412: 400 psi
2. Elongation, ASTM D 412: 300%
3. Density @77 deg. F 8.5 lb/gal typical
G. Fabricated Flashings: Fabricated flashings and trim are specified in Section 07620.
1. Fabricated flashings and trim shall conform to the detail requirements of SMACNA
"Architectural Sheet Metal Manual" and/or the CDA Copper Development Association
"Copper in Architecture - Handbook" as applicable.
H. Manufactured Roof Specialties: Shop fabricated copings, fascia, gravel stops, control joints,
expansion joints, joint covers and related flashings and trim are specified in Section 07710.
1. Manufactured roof specialties shall conform to the detail requirements of SMACNA
"Architectural Sheet Metal Manual" and/or the NRCA "Roofing and Waterproofing
Manual" as applicable.
I. Pipe Housing Waterproofing: provide "dog house" detail as provided on the plans at
locations where lead flashing are not applicable. Fill detail with waterproofing material as
recommended by manufacturer.
07550-8 ADDENDUM #1