POWER OF ATTORNEY


KNOW ALL PERSONS BY THESE PRESENTS that the undersigned hereby authorizes,
designates, and appoints Donald McAleenan and Jeffrey A. Wier as such person's
true and lawful attorneys-in-fact and agents, with full power of substitution
and resubstitution and full power to act, for the undersigned and in the
undersigned's name, place, and stead, to execute, acknowledge, deliver, and file
any and all statements required to be filed with the United States Securities
and Exchange Commission (the "Commission") by the undersigned pursuant to 1)
Section 16 of the Securities Exchange Act of 1934, as amended (the "1934 Act")
or 2) Rule 144 promulgated under the Securities Act of 1933, as amended (the
"1933 Act"), and the rules and regulations thereunder with respect to securities
of Builders FirstSource, Inc., a Delaware corporation, including, without
limitation, statements on Form 4, Form 5 and Form 144 (and any amendments
thereto) and any successor forms adopted by the Commission, as required by the
1934 Act or the 1933 Act and the rules and regulations thereunder, and to take
such other actions as such attorneys-in-fact may deem necessary or appropriate
in connection with such statements.

This power of attorney shall continue in effect until the undersigned no longer
has an obligation to file statements under Section 16 of the 1934 Act or Rule
144 under the 1933 Act, or until specifically terminated in writing by the
undersigned.  The undersigned acknowledges that the aforesaid persons are not
assuming any of the undersigned's responsibilities to comply with Section 16 of
the 1934 Act or Rule 144 under the 1933 Act.

IN WITNESS WHEREOF, the undersigned has duly executed this power of attorney on
the 14th day of November, 2017.




By:	/s/ Daniel Agroskin