PROJECT. ALL CHANGES, ADDITIONS AND DELETIONS ......524 Sq. Re-roofing Addendum #1- You must acknowledge read receipt for any project bidding on! Start Date- See Section 01010-3. Discuss

Department of Facilities and Transportation Services

Office of Design and Construction Services

8115 Gatehouse Road, Suite 3500

Falls Church, Virginia 22042-1203

ADDENDUM #1

Date: September 29, 2020

Project: Chantilly High School Roof Replacement Project (Bid # 21-010)

THIS ADDENDUM IS SUPPLEMENTARY TO THE PLANS AND SPECIFICATIONS FOR THE PROJECT. ALL CHANGES, ADDITIONS AND DELETIONS SHALL BECOME PART OF THE CONTRACT AS IF ORIGINALLY CALLED FOR IN THE SPECIFICATIONS.

PRE-BID CONFERENCE AGENDA

Pre-Bid Meeting for Chantilly H.S. 9/28/2020 Bid- 10/7/20 Start Summer 2021 524 Sq. Re-roofing

Addendum #1- You must acknowledge read receipt for any project bidding on!

Start Date- See Section 01010-3.

Discuss Winter Break (12/19/2020- 01/02/2021)

Two weeks kids are off, Spring Break (03/27/2021- 04/03/2021)

Saturday work available but optional. Must start the winter projects 12/21/20 weather permitting. Both schools no exceptions!

Roofs must be vacuumed off. Contact us for accessibility.

Substantial completion date- 8/21/2021- all hot work completed. Metal work can continue. No work of any kind the first week of school.

Final completion date- 09/30/21. All punch list items are complete and accepted by the Owner.

Only roof areas shown on the roof plan provided are to be replaced.

This is a complete tear off project!

07510 (B/U/R) and 07530 (TPO) are the roofing types.

Manufacturers are Johns Manville, Firestone, Soprema and GAF only!

Refer to 07510 for the guidelines with these manufacturers. Roofing is a 20 year NDL warranty.

Addendum #1 (21-010) Page 1 of 5

Insulation: 2 layers 2.5” ISO mechanically attached staggering each layer. Over the existing deck (confirm deck types). ½” cover board staggered in full mopping of asphalt. Felts: JM Type 4 Soprema Type 4 Firestone Type 4 GAF Type 4 Base Flashing: JM 1 ply DYNA BASRPR and 1 ply DYNA GLAS FR CR G Soprema 1 ply Sopralene Sandes PS and 1 ply Sopra Star FLAM Firestone 1 ply premium base and 1 ply Ultra White GAF 1 ply Rubberoid mop smooth 1.5 and 1 ply Siplast Parafor 30BW #15 lb. felt installed at all curbs and perimeter walls-no exceptions! All cants and tapered insulation in solid asphalt. Replace all roof drains: All drain assemblies including the deck pans. Drain insulation is 1” hard wrap covering the entire drain underneath. Sump is 12’ x12’. See detail 07-5. Cover the entire sump area with base flashing material and extend a minimum of 6” out on to the roof. Prime both sides of the lead. Strip in the lead with 2 plies prior to installing base flashing. Replace all P/P with either stainless steel or copper. Liquid flashing is preferred and use P/P only where approved by FCPS. Abandoned curbs/ P/P, dunnage, PRV or capped off curbs will be removed and the deck infilled with the same material. All P/P, pipe flashings will be stripped in with 2 plies of felt. All gravel stops connecting with the B/U/R system will be stripped in with 2 plies of felt then covered with a ply of base flashing. Stone is Texas #7 White A.S.T.M. #1863 only Allowance for projects is $25,000.00- do not forget to add. Liquid flashing at drains, gravel stop edges and scuppers-no roof cement. Note-wall panels- see roof drawing! Ground coverage-must cover sidewalks and grounds with plywood! You don’t cover, you will replace! Work in the school prior to the school ending is by FCPS approval only!


Check the roof plans closely. Any questions ask before you install. QUESTIONS/ANSWERS/STATEMENTS FROM BIDDERS Question 1: What happens with the Mitsubishi units? Answer 1: We will have them disconnected if necessary. The contractor following detail 07-

17 in the project plan book is to build a wood curb, flash the curb, and install a stainless-steel metal cap to set the unit on. Contractor is to re-use the Portal-Plus multi penetration flashing.

Question 2: Where are crickets to be installed. Answer 2: Only where the roof areas have existing structural slope. Question 3: How high does the contractor have to run the base flashing on the wall area

towards the front of the school (library and media center)? Answer 3: Flash wall area to top of the parapet. Question 4: Do the contractors remove the new roofing between the two large units and the

expansion joints? Answer 4: No, do not remove roofing between the large units and the expansion joints,

have new roof tie onto these areas.

Paul Liverman, Roofing Manager Office of Design and Construction Services Attachments: Pre-Bid Attendees List Plan Holders List cc: Contract File




Documents

PROJECT. ALL CHANGES, ADDITIONS AND DELETIONS ......524 Sq. Re-roofing Addendum #1- You must acknowledge read receipt for any project bidding on! Start Date- See Section 01010-3. Discuss