Addendum 1_Fire Lab Roof Replacement.docx

Addendum 1 Fire Sciences Lab Roof Replacement Solicitation No. 1240LT25R0017

1. The intent for this roof replacement is to do so using the most economical attachment method that meets code and manufacturer requirements, and that includes a 20-year warranty as described in the specifications. The SOW states ballasted for A, B, and C-Wing because we assumed this was the most economical method given existing ballast that can be reused. However, mechanically attached, fully adhered, and ballasted are all acceptable as long as they meet code, manufacturer, and warranty requirements. Please indicate which method you plan to use in your bid proposal. There will not be any preference given to one method over another when evaluating proposals. Adhered walkway pads from the manufacturer may be used in lieu of concrete pavers if not using ballast. Any engineering or calculations required, such as fastening patterns/spacing, are to be performed by the manufacturer or a qualified professional engineer, and costs for such paid by the contractor.

2. All roofs appear to have existing vapor barriers over the decks.

3. Replacement of all existing insulation and cover board at the A and C-Wings is to be included in the base bid, due to damp or deteriorated existing insulation at these locations. Existing height of insulation + cover board at A and C-Wings ranges from approximately 2” to 3” depending on distance from drains. New insulation at these wings is to be polyiso with ½” cover board that meets R-30 minimum. If there are termination/flashing height conflicts at certain portions of the roof, R-30 average is acceptable to resolve conflicts.

4. At B and D-Wings, existing insulation and cover board will be replaced selectively as needed if areas are found to be damp or deteriorated. Quantities have been included in the updated Schedule of Items; any unused quantity is to be credited back. Assume full depth insulation replacement where needed. B-Wing has around 6” to 7” of EPS insulation, and D-Wing has 8” minimum with up to 13” at corners.

5. The two RTUs at the D-Wing have insufficient flashing height, and any new termination without lifting the units would have to be even lower. As such, lifting these units and increasing curb height to meet minimum 8” flashing height is to be included in the base bid.

6. An optional item has been added for modification of the two existing HSS supports under the two RTUs at the middle section of A-Wing. This optional item involves welding additional HSS sections to the four corner posts of the HSS supports for added height, such that it can sit on the concrete roof deck and have 8” of clearance from the roof membrane. If this option is selected, the roof membrane would be flashed around the corner posts of the HSS supports, so a watertight top plate is needed. If this option is not selected, the HSS supports will be set back on top of the roof membrane with protective pads after roof replacement. Delegated design/engineering for the HSS modifications are to be performed by a qualified professional engineer, and costs for such included in the optional item.

7. Any mechanical units or components that are currently on wood blocking are to be placed on new HVAC stands of similar height.

8. Increasing A, B, and C-Wing insulation to R-38 has been moved to an optional item.

9. New fall protection guardrail may be OSHA compliant permanent free-standing, non-penetrating guardrail in lieu of fastening to deck or parapet, except next to the B-Wing staircase as there is not enough room between the stairs and roof edge.

10. Window replacement options are to include new exterior sills.

11. Any interior finish removal necessary to perform window and storefront replacement is to be put back or replaced with like-in-kind finishes.

12. Any removal and reinstallation of the brise soleil shades as needed to replace the second-floor windows is to be included by the contractor.

13. Specification section 088000 mentions both annealed and fully tempered glass. Fully tempered glass is to be used.

14. Hazardous materials reports for the building have been provided. Note that there is asbestos in the window sealant and glazing. Abatement needed to perform the work is to be included by the contractor.