Qadad
Qadad (
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]
Traditional preparation
After collecting blocks of lime stone, they were fired in a
Traditional application
With the now ready mixture of lime and volcanic cinders, they would apply three-layers of qadad-plaster to the walls of cisterns to make them impermeable; the first layer having the largest particles of volcanic cinders (scoria) and the least amount of lime was applied to rough stone, the plaster being added to a thickness of about two inches. They took a sharp-edged stone and, for several days, pounded and rubbed the first layer of qadad firmly onto the wall, all the while sprinkling it with lime-water to keep it wet.[9] The second layer was applied after fully working the first layer by beating. The first process was repeated, this time the wall being plastered with a mixture of qadad containing smaller particles of volcanic cinders and more lime. A sharp-edged stone was again used to pound the qadad firmly onto the wall, all the while sprinkling it with lime-water to keep it wet. Finally, the third layer was applied containing the smallest particles of volcanic cinders and the largest quantity of lime and worked with a sharp-edged stone (one part aggregate to two parts lime, and pounded to a fine paste), and lime-water spattered on the wall to maintain its wetness.[3] After the final application, the wall was treated with a very finely-ground consistency of qadad which was allowed to dry, and when dried, an application of animal fat (suet) was then smeared on the wall for smoothing and burnishing.[9] The end result is that of a wall that is as hard as smooth-marble with beating.[10]
According to archaeologist Selma Al-Radi, qadad can only be used as a plaster on buildings constructed of stone and baked brick, but it will not adhere to mudbrick, cement blocks or concrete.[3] In Yemen it was traditionally made with two basic ingredients, baked lime and volcanic scoria, other countries have traditionally made-use of fine riverbed sand or pebbles instead of scoria, and which were mixed together with lime for use as a common mortar,[3] or to be used as an impervious wall plaster.
Usage
In
In Islamic architecture, different consistencies of qadad were made for different usages: domes, flat ceilings, vertical walls and decorations in the geometric interlace.[14]
See also
- Limepit (old technique used in calcining limestone)
- Lime plaster
- Plasterwork
- Pozzolan
- Tadelakt, a similar waterproof lime-soap plaster
- Sarooj, a similar water-resistant plaster
References
- Great Mosque of Sana'a
- doi:10.4000/cy.111. Retrieved 13 February 2016.
- ^ a b c d e Selma Al-Radi, "Qudâd The Traditional Yemeni Plaster," Yemen Update, Bulletin of the American Institute for Yemeni Studies (AIYS), no. 34 (1994):6-13
- ^ "Fodde. The Architecture of Mud and Qudad. DVD Reviews". Internet Archaeology. intarch.ac.uk.
- ^ Resources, Documentary Educational. "DER Documentary: Qudad". www.der.org.
- ^ docued (11 September 2008). "Qudad, Re-inventing a Tradition - PREVIEW" – via YouTube.
- ^ "Qudad, Re-inventing a Tradition". Documentary Educational Resources.
- ^ "Restoration of the Amiriya Complex - Aga Khan Development Network". www.akdn.org.
- ^ OCLC 863513860.
- Rada'a, the nearly 500-year old existing qadad was so strong that they had to use a sledgehammer to break it apart.
- ^ ""الأشرفية" تحفة "الدولة الرسولية" ورائعة العمارة اليمنية". www.alkhaleej.ae.
- ^ "جامع-المظفر-أو-(المدرسة-المظفرية)". www.gu-yc.org.
- ^ OCLC 48323774.
- ^ Caterina Borelli, Qudad - Reinventing a Tradition (documentary)
External links
- Caterina Borelli, Caterina Borelli: "QUDAD - reinventing a tradition - English version" on Rada, Yemen, using the ancient waterproofing technique with qudad.