Exhibit 12.1

USG Corporation
Ratio of Earnings to Fixed Charges
(dollars in millions)

	June 30,			Year Ended December 31,
	2010			2009			2008			2007			2006			2005
Earnings:
Pretax Income from Continuing Operations	$	(194	)	$	(337	)	$	(581	)	$	88		$	490		$	(2,342	)
Add: Fixed charges		89			167			105			120			556			5
Less: Interest Capitalized		—			(3	)		(19	)		(15	)		(1	)		—
Total Earnings	$	(105	)	$	(173	)	$	(495	)	$	193		$	1,045		$	(2,337	)
Fixed charges:
Interest Expensed and Capitalized	$	85		$	153		$	102		$	103		$	556		$	5
Amortized Premiums, Discounts and Capitalized Expenses Related to Indebtedness		4			14			3			17			—			—
Total Fixed Charges	$	89		$	167		$	105		$	120		$	556		$	5
Ratio of earnings to fixed charges
		—	(a)		—	(b)		—	(c)		1.6x			1.9x			—	(d)

(a)	As a result of a net loss, the amount of the coverage deficiency for the six months ended June 30, 2010 was $194 million.
(b)	As a result of a net loss, the amount of the coverage deficiency for the year ended December 31, 2009 was $340 million.
(c)	As a result of a net loss, the amount of the coverage deficiency for the year ended December 31, 2008 was $600 million.
(d)	As a result of a net loss due to a $3.1 billion pretax provision for asbestos claims, the amount of the coverage deficiency for 2005 was $2.3 billion.