Experts assess the ravages of time on the Alamo

Master stone mason Miroslav Maler uses materials as close to the originals as possible to make repairs to the Alamo, Wednesday, Oct. 28, 2015, in San Antonio. The Alamo is undergoing $5 million in emergency repairs, part of a sweeping, state Legislature-approved $31.5 million makeover that may be one of the siteâs most-ambitious since the days of Davy Crockett. (AP Photo/Eric Gay)

Master stone mason Miroslav Maler pauses while making repairs to the Alamo, Wednesday, Oct. 28, 2015, in San Antonio. Centuries of rainfall and punishing Texas sunshine are slowly doing what cannon fire and barrages of Mexican bullets couldnât back in 1836--disintegrating the Alamo. (AP Photo/Eric Gay)

Master stone mason Miroslav Maler uses materials as close to the originals as possible to make repairs to the Alamo, Wednesday, Oct. 28, 2015, in San Antonio. Centuries of rainfall and punishing Texas sunshine are slowly doing what cannon fire and barrages of Mexican bullets couldnât back in 1836--disintegrating the Alamo. (AP Photo/Eric Gay)

Alamo conservator Pam Rosser, an expert on historic restoration and preservation, uses a portable microscope to record color pigments used on the walls of the Alamo, Wednesday, Oct. 28, 2015, in San Antonio. The Alamo is undergoing $5 million in emergency repairs, part of a sweeping, state Legislature-approved $31.5 million makeover that may be one of the siteâs most-ambitious since the days of Davy Crockett. (AP Photo/Eric Gay)

Master stone mason Miroslav Maler works on repairs to the Alamo, Wednesday, Oct. 28, 2015, in San Antonio. The Alamo is undergoing $5 million in emergency repairs, part of a sweeping, state Legislature-approved $31.5 million makeover that may be one of the siteâs most-ambitious since the days of Davy Crockett. (AP Photo/Eric Gay)

Ivan Myjer, a stone conservator based in suburban Boston who has helped restore historic sites around the world. make repairs to the Alamo, Thursday, Oct. 29, 2015, in San Antonio. The Alamo is undergoing $5 million in emergency repairs, part of a sweeping, state Legislature-approved $31.5 million makeover that may be one of the siteâs most-ambitious since the days of Davy Crockett. (AP Photo/Eric Gay)

A hole measuring about 2 feet on the Alamo's south facade is exposed during repairs to the church, Thursday, Oct. 29, 2015, in San Antonio. Experts believe the hole may have been created during construction of the Alamo to help anchor temporary scaffolding. The Alamo is undergoing $5 million in emergency repairs, part of a sweeping, state Legislature-approved $31.5 million makeover that may be one of the siteâs most-ambitious since the days of Davy Crockett. (AP Photo/Eric Gay)

Mortar crumbs rest on a ledge as repairs are made to the Alamo, Wednesday, Oct. 28, 2015, in San Antonio. The Alamo is undergoing $5 million in emergency repairs, part of a sweeping, state Legislature-approved $31.5 million makeover that may be one of the siteâs most-ambitious since the days of Davy Crockett. (AP Photo/Eric Gay)

FILE - In this March 6, 2013, file photo, John Potter, a member of the San Antonio Living History Association, patrols the Alamo in San Antonio, during a pre-dawn memorial ceremony to remember the 1836 Battle of the Alamo and those who fell on both sides. The former 18th century Spanish mission is poised to undergo one of the most significant transformations in its history as the state moves to purchase nearby commercial buildings and launch a planning review that could bring dramatic changes. (AP Photo/Eric Gay, File)