Quanex Building Products Corporation
Power of Attorney

The undersigned hereby constitutes and appoints Paul Cornett, Kevin Delaney,
and Brent Korb his true and lawful attorneys-in-fact and agents,
with full power of substitution and re-substitution, for him and in his name,
place and stead, in any and all capacities,
to complete and sign all Form 3s, Form 4s and Form 5s relating to equity
securities of Quanex Building Products Corporation
and to file the same, with all exhibits thereto or documents in connection
therewith, with the Securities and Exchange Commission,
the New York Stock Exchange and Quanex Building Products Corporation,
granting to said attorney-in-fact and agent,
full power and authority to do and perform each and every act and thing
requisite and necessary to be done in and about the premises,
as fully to all intents and purposes as he might or could do in person,
hereby ratifying and confirming all that said attorney-in-fact and agent,
or substitute or substitutes, may lawfully do
or cause to be done by virtue hereof.

Executed this 22nd day of March, 2019.


/S/ Donald R. Maier
Donald R. Maier