BID 2023-95 Clarifying Questions 4.pdf
PDF 181 KB Posted
- Attached to
- Fresh Produce
- Solicitation number
- S-P00400-00008631
- Issued by
- Multnomah County, Gladstone City, Oregon
About this file
This document is a clarification response issued by Mt. Hood Community College (MHCC) in response to questions submitted by interested bidders regarding Invitation to Bid #2023-95 for the Pamplin Building Single Ply Membrane Re-roof project. The clarification addresses the scope of work regarding roof tear-off specifications and material requirements. In response to bidder inquiries about the extent of tear-off work, the college clarified that contractors must tear down to the existing 3-inch insulation layer and install a 1/2-inch polyisocyanurate recover board over that insulation, with repair and replacement of any damaged 3-inch insulation as necessary. Contractors must also perform precision removal of roof system components and flashings at perimeters to accommodate roofing manufacturer's standard installation details in compliance with federal, state, and local regulations.
The specifications detail the required High Density Polyisocyanurate Recover Board materials, which must be non-combustible, water-resistant boards measuring 48 inches by 96 inches with a 1/2-inch thickness and R-value of 2.5, along with defined compressive strength, density, and mold growth resistance requirements meeting ASTM standards. The recover board must be Factory Mutual approved for use with FM 1-60 and 1-90 rated roofing assemblies. Insulation fasteners must be the type and size specified by the roofing membrane manufacturer and supplied by that manufacturer to ensure compliance with roofing system warranties. This clarification document was issued on December 11, 2023, and serves to align bidder understanding of project requirements prior to proposal submission.
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| File | Type | Posted |
|---|---|---|
| RFP 2023 - Fresh Produce.pdf |
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Text version
INVITATION TO BID #2023-95
Pamplin Building Single Ply Membrane Re-roof (“BID”)
RESPONSE TO CLARIFYING QUESTIONS #4
December 11, 2023
Note that these are questions submitted by interested firms to the above referenced solicitation.
The below answers are for clarification purposes only and in no way alter or amend the BID as published.
1. Since scope has changed to tear off we need clarification on what components need to be torn off.
Are we to just tear off the current SBS and leave the existing coverboard and insulation or will this be a full tear off down to roof deck?
If the answer is full tear off down to roof deck then we have a couple other follow up questions:
Will we need to include R30 insulation in our bid? (2 layers of 2.6” polyiso insulation).
Will there still be a need for a coverboard if we are adding polyiso insulation?
Answer: Tear down to existing 3” insulation and install ½” polyisocyanurate recover board over the 3” insulation. Please refer to the specification for more detail. Repair and replace damaged 3” insulation.
Neatly provide precision removal of portions of the existing roof system and flashings at perimeters as necessary to allow for installation of roofing membrane manufacturer's standard details in accordance with roofing manufacturer's published instructions and recommendations for the specified roofing system.
Comply with federal, state, and local regulations.
2.01 ROOF INSULATION AND COVER BOARDS
A. High Density Polyisocyanurate Recover Board: Non-combustible, water resistant, high density closed cell polyisocyanurate core with coated glass mat facers, with the following characteristics:
1. Size: 48 inches by 96 inches, nominal.
2. Thickness: 1/2 inch.
3. Thermal Value: R-value of 2.5, when tested in accordance with ASTM C518 and
ASTM C177.
4. Surface Water Absorption: 3 percent, maximum, when tested in accordance with
ASTM C209.
5. Compressive Strength: 120 psi, when tested in accordance with ASTM D1621.
6. Density: 5 pcf, when tested in accordance with ASTM D1622.
7. Factory Mutual approved for use with FM 1-60 and 1-90 rated roofing assemblies.
8. Mold Growth Resistance: Passing ASTM D3273.
Insulation Fasteners: Type and size as required by roof membrane manufacturer for roofing system and warranty to be provided; use only fasteners furnished by roof membrane manufacturer.
End of Clarifying Questions #4
File details come from the government source that posted it. Updated .