Exhibit 12.1

OWENS CORNING AND SUBSIDIARIES

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

The following table sets forth our ratio of earnings to fixed charges for the periods indicated:

	Nine Months Ended September 30, 2017			Twelve Months Ended December 31,
				2016			015			2014			2013			2012
Ratio of Earnings to Fixed Charges		4.6			4.8			4.1			2.5			2.8			(a	)
The computation of the ratio of earnings to fixed charges is as follows (in millions):
	Nine Months Ended September 30, 2017			Twelve Months Ended December 31,
				2016			2015			2014			2013			2012
Earnings:
Earnings from continuing operations before taxes	$	435			590			453			232			273			(40	)
Fixed charges (see below)		121			154			143			157			153			158
Amortization of capitalized interest		9			11			9			8			7			6
Capitalized interest		(9	)		(16	)		(14	)		(10	)		(8	)		(13	)
Noncontrolling interest in pre-tax income of subsidiaries that have not incurred fixed charges		—			—			—			—			—			—
Earnings, as adjusted	$	556			739			591			387			425			111
Fixed charges:
Portion of rents representative of interest expense(b)	$	21			26			29			30			28			26
Interest on indebtedness, including amortization of deferred loan costs(c)		91			112			100			117			117			119
Capitalized interest		9			16			14			10			8			13
Total fixed charges	$	121		$	154		$	143		$	157		$	153		$	158

(a) In 2012, the ratio of earnings to fixed charges was less than 1.0. During 2012, the Company needed to generate an additional $47 million of earnings from continuing operations before taxes to attain a 1.0 ratio of earnings to fixed charges.

(b) The Company estimates that 33% of its rental costs represent interest expense. This factor has been applied to all periods presented in the table above.

(c) Interest on indebtedness excludes interest income, gain or loss on extinguishment of debt, and interest associated with uncertain tax positions, which is included in Income tax expense in the Consolidated Statements of Earnings.