Solicitation_QA__2.pdf

GSA Solicitation No. GS-02-P-17-PW-C-0001 Construction for James M. Hanley Federal Building Upper Envelope Additional Questions and Answers

Question 1. Refer to detail 1/AE501. The flashing is shown to terminate with a T-bar and counter flashing at a height of eight (8) inches above the step-in-the-wall. Currently, there are numerous D-ring tie-offs attached to the wall in this 8-inch space. Please advise on how the D-rings should be addressed. (Should they be removed, for instance? Should the roof terminate below the D-rings? Another option?)

Answer 1. Install roof flashing to bottom of D-Ring locations (D-Rings are to remain in place). All other areas to be 8” min. height.

Question 2. Section 075400, paragraph 2.5.A calls for R-25 insulation. Keynotes 1/AE101, 5/AE102, 8/AE102, 1/AE103, and 6/AE103 call for insulation R-values other than R- 25.

Which prevails, the specification or the keynotes?

Answer 2. R-25 is a minimum rating due to varying conditions on multiple roofs.

Drawing Keynotes shall govern, unless noted otherwise. Note: Areas on the “South Tower” (refer drawing AE102) shall maintain the same height of insulation installed as currently existing in order to eliminate potential termination issues created by the large quantity of mechanical equipment on this section of roof.

Question 3. Section 075400, paragraph 2.5.C calls for taper insulation. Does this occur anywhere other than the gray-shaded "cricket areas" shown on this roof plans?

Answer 3. Tapered insulation is typically noted by shaded areas with ¼” / 1’-0” markers.

Question 4. For the gray-shaded crickets areas, are we to use insulation boards factory-fabricated to a 1/4" per foot slope, or is the combined slope of the cricket board and the underlying structural slope supposed to be 1/4" per foot (meaning factory fabricated slope in the board would have to be greater than 1/4" per foot).

Answer 4. Design intent is to provide a reverse slope that is equivalent to ¼” per foot.

In some areas, thickness would be greater than ¼” per foot.

Question 5. Section 075400, paragraph 2.5.D states that the "roof system (vapor retarder, insulation, cover board, and membrane) thickness [shall] not exceed six (6) inches." In areas that may receive R-30 insulation, the total system thickness will exceed six (6) inches. Please confirm if roof can exceed the 6" thickness or if we should reduce the insulation thickness.

Answer 5. Roof section R15A depicted as “South Tower” (refer drawing AE102) is to maintain the same height of insulation installed as currently existing in order to eliminate potential termination issues created by the large quantity of mechanical equipment on this section of roof. This is also referred to on Drawing AE102, Keyed Note 5.

Question 6. For the purposes of this project, is a Torch-applied sheet vapor retarder (title of Section 071326) the same thing as a Self-Adhering Sheet Vapor Retarder (footer of Section 071326 and as mentioned in 075400, paragraph 2.4)?

Answer 6. Any reference to “Self-adhering membrane” shall be deleted. Torch-applied sheet vapor retarder is required.

Question 7. Refer to Roof 15A on Sheet AE102. The roof legend for the hatch-marks on this roof state to install minimum R-25 insulation. Keyed Note 5 on this roof section states to install 2-1/2", R-15 insulation. Which is correct?

Answer 7. To the extent possible, follow Keyed Note 5, as pre-existing conditions in several areas will limit the installation of R-25 thicknesses.

Question 8. Refer to Roof 15A. Which portions of this roof area receive taper insulation? Is there a structural slope in any portion of this roof deck?

Answer 8. Roof 15A has a structural slope. Past renovation has altered this slope in ways that require additional tapered insulation to provide proper drainage.

Question 9. Refer to Roof 15C on Sheet AE102. The roof legend for the hatch-marks on this roof state to install minimum R-25 insulation. Keyed Note 8 on this roof section states to install 6", R-30 insulation. Which is correct?

Answer 9. To the extent possible, follow Keyed Note 5, as pre-existing conditions in several areas will limit the installation of R-25 thicknesses.

Question 10. Refer to Roof 16 on Sheet AE102. Keyed note 8 states to install 6" XPS. The gray hatching states to install taper insulation. Is the taper insulation in addition to the 6" XPS?

Answer 10. Correct. This roof section has no structural slope.

Question 11. Refer to Roof 2 on Sheet AE103. The roof legend for the hatch-marks on this roof state to install 6", R-30 insulation. Keyed Note 6 on this roof section states to install 4", R-20 insulation. Which is correct?

Answer 11. Keyed Note 6 is indicated, as the existing roof edge limitations prevent a full

6” R-30 insulation installation.

Question 12. See keynote 5 and Sheet AE103. Please provide a reference for detail

Answer 12. Refer to Detail #2 on Drawing AE504.

Question 13. Is there a specific design criterion for the new lightning protection system (material type, etc.)?

Answer 13. Follow notes on EP-Series Drawings and Specification Section 26114 –

Lightening Protection System.

Question 14. Does the underground parking boundary reach past the plaza deck boundary lines referenced on Drawing G-002?

Answer 14. Plaza deck boundary starts is one sidewalk width from the road.

Believe the sidewalk width in this situation is 8 ft.

Question 15. Are there any tunnels or pipe chases in the crane staging locations shown on Drawing G-0002?

Answer 15. None owned by US Gov. as this is City of Syracuse property.

Contractor shall expect normal underground utilities to be present.

Question 16. Can crane outriggers set up on properly protected sidewalk areas in the crane staging areas shown on G-0002?

Answer 16. Not on any area considered on or within plaza deck area as the weight limitation (shown as not on drawing) of the plaza would be exceed.

Question 17. Are alternate material handling and hoisting methods (other than crane method) permissible on this project? We understand chutes are not permitted.

Answer 17. GSA does not object to use “coordinated off hour” use of the freight elevator provided compliance with weight limitation (8,000 lb) of freight elevator. Freight elevator highest stop is 14th floor whereby access to north tower roof is one additional flight of stairs up.

Question 18. It was said that the new roof system going back was not going to be thicker than the existing system being removed. This was to avoid conflict with existing flashing heights. The existing roof is approximately 3" thick. The drawings however suggest that we are installing 6" of insulation and a 1/2" cover board (note 1 in keyed notes). The details reflect a variety of different insulation thicknesses at each roof level. What insulation thickness will we be installing, and does it vary from roof level to roof level?

Answer 18.

1. The South Tower, specifically Roof Area R15A, must maintain the existing flashing heights due to the density of roof top equipment located in this area that cannot be removed or disconnected. Therefore, less than 6” insulation will be installed here as shown.

2. The North Tower is not an issue and 6” insulation can be installed as shown on the documents.

3. Due to the parapet wall mounted D-Rings that will remain in-place, flashing heights will be adjusted to terminate just underneath them.

4. The Annex roofs, unless noted otherwise, can accommodate the 6” of insulation called for.

Question 19. Please clarify if all existing concrete surfaces need to be recoated or just patched at locations that are disturbed?

• General roofing plan note 9 states contractor to ensure all concrete surfaces are to be protected and sealed. If concrete surfaces are to remain they must be coated with Dow corning all guard grindstones.

• Statement of work states re-coat with exact same coating material and sealant any concrete/parapet/façade portions of the building left exposed disturbed and or damaged.

Answer 19. Contractor is only expected to address locations that are damaged, disturbed and or left exposed by how the work was performed.