B09-_P1523Q0012_Amendment__3_Questions_and_Answers_0003.pdf

Solicitation # 140P1520R0017; Amendment# 2 Questions and Answers from Site Visit held on Feb 23rd, 2023

General

1. Question: Can you provide any information on the existing roof that needs to be torn off?

Answer: There is an unknown number of roll roofing material layers, the park staff suspects up to two layers of roll roofing with accompanying underlayment.

2. Question: The solicitation mentions replacement of damaged decking. Is this decking composed of 1x8 boards? Approximately how much is damaged?

Answer: Decking on surrounding buildings has been 1” board decking, width varies. Recent leaks in the building have occurred in the southern most unit of this triplex apartment unit.

3. Question: What thickness of poly-iso insulation is required?

Answer: Provide and install one layer of 2” poly-iso insulation.

4. Question: It appears in photos that the roof has some slope built in. Will tapered insulation be required to add additional positive drainage?

Answer: SOW Section 2.a.vii states that roof system to slope minimum ¼” for every 12” towards existing roof drains/canales.

5. Question: The general requirements call for a fully adhered vapor barrier and underlayment, while the specifications only call for a mechanically-attached slip sheet. Generally, none of these are needed when replacing the poly-iso insulation and installing a coverboard. What are all the layers that the government would like on this roof?

Answer: SOW Section 3.c.ii states “Material Compatibility: Provide roofing materials that are compatible with one another under conditions of service and application required, as demonstrated by roofing membrane manufacturer based on testing and field experience”

6. Question: On the "Cool Roof" requirements, it is specified that the roof must have an Initial

Solar Reflectance ≥ 88%, and Initial Thermal Emittance ≥ 87%. I searched the Cool Roof

Council catalog, and there are no tan PVC roofs that meet this criteria, only bright white.

Consider revising to 72% ISR and 85% ITE, which will allow a few competing products to qualify.

United States Department of the Interior

NATIONAL PARK SERVICE

INTERMOUNTAIN REGION

Arizona Major Acquisition Buying Office

1824 South Thompson Street, Suite 200

Flagstaff AZ 86001

Answer: The government revised specification for Cool Roof requirements shall be the following:

• Initial Solar Reflectance: ≥35%

• Initial Thermal Emittance: ≥ 80%

• Initial Solar Reflective Index (SRI): ≥ 40

• 3‐Year Aged Solar Reflectance: ≥ 25%

• 3‐Year Aged Thermal Emittance: ≥ 75%

• 3‐Year Aged Solar Reflective Index (SRI): ≥ 30

7. Question: Is the contractor responsible for sealing the entire chimney walls? Or only up to the counterflashing, approximately 12" above the roof? Will new counterflashing be required?

Answer: The government is in the process of sealing chimney walls. The contractor shall install counterflashing and/or make repairs that will ensure that the required manufacturer’s warranty can be issued.

8. Question: How will the roof be terminated on the exterior wall? It appears that the existing roof is terminated on top of the wall. If using a termination bar on top of the wall, then there doesn't seem to be any need for fascia bar or vinyl-coated metal. A far-superior solution would be to terminate on the outside face and cover the wall with a new metal cap, but the edge of the cap would be visible from the ground.

Answer: The original stone parapet walls shall be preserved to the greatest extent possible while providing a watertight roofing system. The government will consider modifications to the stucco finished wall including the suggested metal capped termination