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
ADDENDUM #1
Addenda
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
This is the opportunity summary page. It provides an overview of this opportunity and a preview of the attached documentation.