16th century Kuršumlija mosque in Maglaj, Bosnia and Herzegovina - structural repairs, conservation and restoration works

Kalavun Jusuf-Pasha's or Kuršumlija mosque was constructed in 16th century on the right bank of the Bosna River, in the historical area of town of Maglaj. The people are more familiar with the name Kuršumlija mosque, which this monument got after its lead sheet covering (kuršum in Turkish language means lead/plumb).

During the 1992-1995 war in Bosnia and Herzegovina, the building suffered extensive damage: breaches were recorded on the porch cupolas, as well as on the main dome, while the neck of the minaret was almost completely demolished. The situation was further worsen by a long-term problem - the corner sandstone column of the porch, which lost its structural function due to damage and deterioration. Therefore, since 1985, this corner has been secured with a wooden supporting structure in order to prevent the possible collapse of the upper part of the porch structure.

The project for structural repairs, conservation and restoration works on the Kuršumlija mosque was developed by the team of the Institute for the Protection of Monuments of the FBiH in cooperation with the Foundation for Cultural Heritage without Borders CHwB from Sweden (established in 1995, active in Bosnia and Herzegovina since 1996) with the aim of repairing the damage in a way that preserves its historical authenticity as well as the application of traditional materials and techniques.

The first phase of the restoration works included the construction of scaffolding around the mosque and a protective roof covering over the building with the aim of enabling it to dry out.

Porch

The second phase of the project included repairing the breaches in the porch cupolas, which were walled-up with blocks of travertine stone. The unevenness of their outer surfaces were leveled with lime mortar, which was used as a base to place clay mortar over it.

The clay mortar, reinforced with chopped straw, was polished to a fully flattened surface and covered with the lead sheet that was made with specific details, with the aim of achieving the authentic roofing method.

Main dome

The initial step in the process of repairing the main dome was to dismantle the protective PVC foil, alem (end ornament), and the existing lead sheet. A lime-cement mortar was removed from the dome surface as well as the broken reinforced-concrete ring found at the abutment of the dome. The damaged dome cornice blocks were dismantled, too. Upon completion of the dismantling work, the breaches in the dome (2.00x2.00m) were repaired, as well as several radial cracks.

For structural and aseismic reasons, the abutment of the dome was tight with reinforcing cables, hidden in shallow channel under the lime mortar. Provided with serial spanners, the cables aimed to take over the structural function of the previously removed reinforced-concrete ring.

A layer of lime plaster was laid over the dome. The base for covering the dome with lead sheet is made of clay mortar.

Corner column

In 1985, a wooden supporting structure was built on the corner of the mosque porch for security reasons, with the aim of taking over the constructive function of the column, which, with its severely damaged capital and disfigured shaft, could no longer function as a structural member.

The replacement of the corner column was carried out extremely carefully. For these purposes, an additional load-bearing wooden structure was made. With the use of hydraulic jacks and securing by supporting wooden joists ("pinning"), the upper part of the porch structure was separated from the columns in the total height of 9 mm - millimeter by millimeter - in order to prevent the sudden release of metal braces, which could be seen in porch both in the longitudinal and lateral direction.

After constructive separation, the braces - anchored in an iron box at the top of the column capital and sealed with lead, were released very carefully. Melting lead in the iron box with a burner was very difficult, because it was 16th century old plumb, which contained a large amount of various impurities of other elements, what increased its hardness.

The new column was made in a stonecutter workshop according to detailed drawings and the original sample. It is composed of three parts - base, shaft and capital, interconnected with metal stainless arbors, sealed with plumb through specially made channels. The joints between the individual parts of the column are enclosed by metal rings. The base of the column was fixed to the pedestal of the porch with arbor sealed with plumb. The capital, as a finishing element, was also made on the model of the original, with the same opening for iron box in which the old metal braces were returned and sealed with plumb.

The complete structure of the upper part of the porch was lowered slowly, keeping scaffolding, supporting wooden joists and hydraulic jacks in situ, as security measure until the mortar bonding process was completed. The entire process of column replacement was monitored by a geodesic surveyor and a structural engineer, too.

The old wooden supporting structure was dismantled after this process, so that the porch is completely visible today.

Upper part of the minaret (neck)

Due to the damage and aging, it was necessary to replace the first two rings of the šerefe (minaret balcony), as well as a few stone blocks finishing the minaret polygonal shaft. The stone blocks, weighing 250-300kg, were marked, dismantled and arranged into rings in the mosque courtyard. According to detailed designs and original samples, new blocks of sandstone were made in the stonecutter workshop. They were arranged into rings on the ground, marked, raised and mounted in their original positions. 

The construction of the upper part of the minaret shaft (“neck”) began with cut blocks of sandstone, interconnected with metal clumps sealed with plumb. All the preserved original blocks are incorporated in the new minaret structure.

The conical roof, whose central segment is a wooden post 15m high, complete the minaret. The post comes out of the roof and carries the hand-made copper alem (end ornament). The roof is covered with lead sheets. The šerefe (balcony) fence was reconstructed on the model of original and preserved pieces, decorated with bas-relief geometric ornamentation on the front surfaces. It is made of small-grained sandstone, as well as decorative stalactite on the balcony consoles. Fence slabs are mutually connected with metal clumps sealed with plumb. They are anchored into balcony with metal arbors, which are also – through the canals – sealed with plumb.

Two-and-a-half years of conservation and restoration work on this remarkable cultural monument were completed in the autumn of 1999. The mosque is in use.

(Note: This text is my original article "Conservation and restoration works on kalavun Jusuf-Pasha's Mosque in Maglaj", published in February 2005 in the magazine "Moj Dom", the first BH magazine for architecture and culture of living).

Company& project: Institute for the Protection of Monuments of the FBiH, Sarajevo (Aleksandar Ninković, Azra Hadžić) in cooperation with the Foundation for Cultural Heritage without Borders CHwB, Sweden; Investor: Swedish International Development Agency (SIDA) via the Foundation for Cultural Heritage without Borders (CHwB), Sweden; Contractor: GD "Gradnja" d.o.o., Zenica; Status: National monument of Bosnia and Herzegovina since 2006; Photos: Institute for the Protection of Monuments of the FBiH, Sarajevo; Video: Amro Ibraković.