Qadad

The Amiriya School, built of qadad
A minaret of the over 1300-year-old Great Mosque of Sana'a in Yemen, which is built with qadad. It is now being restored

Qadad (Arabic: قضاض qaḍāḍ) or qudad is a waterproof plaster surface, made of a lime plaster treated with slaked lime and oils and fats. The technique is over a thousand years old, [1][2] with the remains of this early plaster still seen on the standing sluices of the ancient Marib Dam.[3]

Volcanic ash, pumice, scoria (Arabic: شاش), in the Yemeni dialect, or other crushed volcanic aggregate are often used as pozzolanic agents, reminiscent of ancient Roman lime plaster which incorporated pozzolanic volcanic ash.

Due to the slowness of some of the chemical reactions, qadad mortar can take over a hundred days to prepare, from quarrying of raw materials to the beginning of application to the building. It can also take over a year to set fully.[4]

In 2004, a documentary film Qudad, Re-inventing a Tradition[5] was made by the filmmaker Caterina Borelli.[6][7] It documents the restoration of the Amiriya Complex, which was awarded the Aga Khan Award for Architecture in 2007.[8]

  1. ^ see Great Mosque of Sana'a
  2. ^ Sutter, Anita (18 December 2006). "Note sur la fabrication du qadâd". Arabian Humanities. 6–7 (6–7). doi:10.4000/cy.111. Retrieved 13 February 2016.
  3. ^ Cite error: The named reference SelmaAlRadi1994 was invoked but never defined (see the help page).
  4. ^ "Fodde. The Architecture of Mud and Qudad. DVD Reviews". Internet Archaeology. intarch.ac.uk.
  5. ^ Resources, Documentary Educational. "DER Documentary: Qudad". www.der.org.
  6. ^ docued (11 September 2008). "Qudad, Re-inventing a Tradition - PREVIEW" – via YouTube.
  7. ^ "Qudad, Re-inventing a Tradition". Documentary Educational Resources.
  8. ^ "Restoration of the Amiriya Complex - Aga Khan Development Network". www.akdn.org.