Exhibit 1

AGREEMENT

JOINT FILING OF SCHEDULE 13D

The undersigned hereby agree to jointly prepare and file with regulatory authorities this Schedule 13D and any future amendments thereto reporting each of the undersigned’s ownership of securities of GCP Applied Technologies Inc., and hereby affirm that such Schedule 13D is being filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained therein, but shall not be responsible for the completeness and accuracy of the information concerning the other, except to the extent that he or it knows or has reason to believe that such information is inaccurate.

Date: September 20, 2018	40 NORTH MANAGEMENT LLC
	By:
		/s/ David S. Winter
		David S. Winter
		Principal

By:
	/s/ David J. Millstone
	David J. Millstone
	Principal

Date: September 20, 2018	40 NORTH LATITUDE FUND LP
	By 40 North GP III LLC, its General Partner
	By:
		/s/ David S. Winter
		David S. Winter
		Principal

By:
	/s/ David J. Millstone
	David J. Millstone
	Principal

Date: September 20, 2018	40 NORTH LATITUDE MASTER FUND LTD.
	By:
		/s/ David S. Winter
		David S. Winter
		Director

By:
	/s/ David J. Millstone
	David J. Millstone
	Director

Date: September 20, 2018	40 NORTH LATITUDE SPV-D LLC
	By:
		/s/ David S. Winter
		David S. Winter
		Principal

By:
	/s/ David J. Millstone
	David J. Millstone
	Principal

Date: September 20, 2018	40 NORTH GP III LLC
	By:
		/s/ David S. Winter
		David S. Winter
		Principal

By:
	/s/ David J. Millstone
	David J. Millstone
	Principal

Date: September 20, 2018	DALBERGIA INVESTMENTS LLC
	By:
		/s/ John Rebele
		John Rebele
		Executive Vice President and Chief Financial Officer

Date: September 20, 2018	STANDARD INDUSTRIES INC.
	By:
		/s/ John Rebele
		John Rebele
		Executive Vice President and Chief Financial Officer

Date: September 20, 2018	Standard Industries Holdings Inc.
	By:
		/s/ John Rebele
		John Rebele
		Executive Vice President and Chief Financial Officer

Date: September 20, 2018	G-I Holdings Inc.
	By:
		/s/ John Rebele
		John Rebele
		Executive Vice President and Chief Financial Officer

Date: September 20, 2018	G Holdings LLC
	By:
		/s/ John Rebele
		John Rebele
		Executive Vice President and Chief Financial Officer

Date: September 20, 2018	G Holdings Inc.
	By:
		/s/ John Rebele
		John Rebele
		Executive Vice President and Chief Financial Officer

Date: September 20, 2018	DAVID S. WINTER
	By:
		/s/ David S. Winter

Date: September 20, 2018	DAVID J. MILLSTONE
	By:
		/s/ David J. Millstone

Date: September 20, 2018	Ronnie F. Heyman
	By:
		/s/ Ronnie F. Heyman