North America Frac Sand (NAFS) 8-K Changes in Registrant's Certifying Accountant

EXHIBIT 16.1

Messineo & Co., CPAs LLC 2471 N McMullen Booth Road, Suite 302 Clearwater, FL 33759-1362 T: (518) 530-1122 F: (727) 674-0511

Office of the Chief Accountant

Securities and Exchange Commission

100 F Street, NE

Washington, D.C. 20549

July 6, 2015

We have read the statements included in the Form 8-K dated July 6, 2015, of Xterra Building Systems, Inc., to be filed with the Securities and Exchange Commission and are in agreement with the statements contained in Item 4.01 insofar as they relate to our firm.

Very truly yours,

Messineo & Co., CPAs, LLC

Clearwater, Florida