Responses to the RFIs Amendment 1.pdf

No. RFI Question Answer

The anchor layout seems a bit arbitrary, are we sticking to the very few locations shown on the drawings or can we improve to provide some actual coverage on the roof. The locations shown will not protect very much of the roof since the coverage from an anchor point to the adjacent roof edge is only a 15 degree swing from perpendicular to the edge. If the goal is to protect the workers while accessing all the equipment (and roof drains) near the roof edge we would suggest a horizontal life line so the users can be tied off pretty much perpendicular to any location around the roof's perimeter.

The anchor layouts are based on AE evaluation of the tie off areas required to service the roof mechanical equipment. The anchor design and locations shall remain as shown.

Do you know the thickness of the concrete deck? From the details it looks like it is an unsupported slab (no metal deck) which is likely good news on the thickness and strength. If it is over 4" and 3,000 psi we can use an adhesive roof anchor which is the easiest option since we wouldn't need access underneath.

The anchor design is based on the design of the existing cast in place slab and integral beam system and shall remain as shown. The design is based on AE’s calculations, experience, and recommendations by the manufacturer.

I'd also like to know the max thickness of the roofing insulation, we'll want to make our anchor 8" taller than that for the roofers to be able to put a boot on the anchor. It looks like the anchor detail (13/A-501) is calling out 18" but I wasn't sure if that was calculated or a random anchor detail the arch put in.

The roof insulation at the main roofs for buildings 4 and 22 will be R-33 with the coverboard as indicated on the drawings. The thickness / R-values for polyiso insulation differs from most manufacturers. The contractor would need to contact the suppliers for specific insulation depth. The contractor will also need to add for the cover board thickness in order to calculate the roof construction thickness. The anchor design and locations shall remain as shown.

523A5-22-001 Replace Roofs Multiple Buildings BID Process RFIs

Existing ductwork and equipment on roof – Is this going to be removed or they will be responsible to store and protect while replacing roof?

The existing roof mechanical equipment such as HVAC units and ductwork will remain. Refer to the demolition plan for information on the total design as there are some roof mounted equipment, conduits, and pipes that will need to be either moved or removed and replaced. The roof removal and installation will have to be worked around the existing conditions. Refer to general note 5 on drawings A-101, and A-102 for additional information. The temporary supports for the ductwork and roof mounted items will be by the contractor.

All other stored materials such as ducts and vents will be removed before construction start date.

5 Is there an Asbestos involved? Is there a report?

A Regulated Building Material Survey Report was completed and none of the materials sampled at the building 4 and 22 roofs were found to be contain greater than 1% asbestos. An assessment for lead containing paint was conducted by visual inspection and no painted surfaces and systems were observed on the roofs of Buildings 4 and 22 with the potential for disturbance during roof replacement. There is no hazardous waste or lead paint removal specified on this project. The hazardous abatement report is attached.

Concrete Deck Moisture tests are called out in the specs to be performed daily prior to any roofing going down. This is not typical on older existing concrete decks, as moisture levels stabilize over time. Would a one time test with one sample per 4000 square feet be acceptable? This would be in accordance with the ASTM F 2170 standard.

The specification section noted above is 070150.19 Preparation for Re-Roofing Section 3.7 Deck Preparation, B,2. Substitute the following, Proivde a one time test with one sample per 4,000 square feet of roof area in accordance with ASTM F 2170 standard. Item “2a” shall remain as stated.

Detail 5/A504 Calls out “ballast as specified” and shows pea stone gravel ballast. Ballast is not specified. Can you confirm this ballast is not intended?

The ballast shall be deleted from that detail as there is no roof ballast required on the project.

Vapor Retarder 072727 is called out to be asphalt/felt which is not typical of new roofing systems and is not included in manufacturer warrantied systems.

Would a Self-adhered AVB typical of the specified roofing system be acceptable? Carlisle SA 725TR or equivalent? Note: 072200 calls out the manufacturer’s warranty to include the vapor retarder and identifies a SA Sheet vapor barrier similar to what I mentioned. What is the intended product?

A self-adhered AVB typical of the specified roofing system is acceptable and can be substituted for the vapor retarders as specified in section 072200, and 072727. This is the basis for design is Carlisle SA 725TR or equivariant.

Is Perimeter Batten Bar Identified by the dashed line at perimeter in drawings?

there is no note or detail that mentions it, is it required in the assembly?

Batten at perimeter 075423- 2.5 E/3.5 E 1, is the typical 1” plastic or polymer batten strip acceptable?

The dashed line on the drawings is an imaginarily reference line for the approximate location of the end of the cant strip. The roof shall be installed as per the manufacturer’s recommendations. If the manufacturer requires a batten strip for the attachment detail at the roof edge or other areas it shall be the material as specified in 075423, 2.5, E.

½” Gypsum substrate board is called out in specs to be fastened to steel deck(072200 2.5 D/ 3.4), but I do not see steel deck and it is not identified in the assembly drawings 1 and 2/A501. Is this a required part of the assembly?

What is attachment at concrete deck?

Section (072200 D/3.4) shall be deleted from the specifications as there are no roof areas with metal decks. Refer to (072200, 3.7) for cover board installation procedures.

11 Could you please provide the test cores analysis?

A Regulated Building Material Survey Report is attached which identifies the location and the composition of the core samples.

Sheet1