Fibreglass Finial (Alem) Manufacture and Design

The alem is the small piece at the very top of a minaret, and it is what finishes a mosque’s silhouette. Classically the alem was beaten from copper; today fibreglass allows the same form to be given more lightly and with a longer life.

We produce the alem end to end in our workshop: three-dimensional modelling of the design, a full-scale model, a negative mould, lamination and surface finishing. The gallery below shows finished finials photographed on site alongside model studies from our design archive — which finial goes where on a given mosque is decided by working through that archive.

How many kinds of finial does one mosque have?

The alem is not only the piece set on top of the minaret. A mosque carries finials at several points, in different proportions, and each needs its own model:

• Minaret finial — the slenderest and tallest proportion; designed to be read from a distance.
• Main dome finial — the largest of the set, scaled to the diameter of the dome.
• Half dome / small dome finial — the same language as the main dome, at reduced proportion.
• Weight tower finial — sits on the turrets around the dome skirt.
• Fountain and porch finials — seen at courtyard scale, from close to the ground.

Why a fibreglass finial is light and long-lived

The weight of the finial governs not only its own support but the method of installation. A fibreglass alem weighs far less than a copper or cast one of the same size, which makes installation at height easier and lowers the anchorage load at the top of the minaret.

• It does not corrode — the chief problem of a metal finial disappears in coastal and humid regions.
• Its thermal movement is low; it does not work the anchorage loose over the years.
• The finish can be renewed — gold leaf or paint can be maintained without removing the finial.

From design to installation

Finial manufacture runs in five steps: three-dimensional design and a study of proportion; a full-scale model; a fibreglass negative mould; lamination with the steel core spindle set in place; and surface finishing. The proportion study is the step most often skipped — the finial will be seen thirty metres up, and a proportion that looks right on a desk reads quite differently there.

Finials for steel minarets

In the steel minaret design we prepared for Dortmund in Germany, the finial was studied to sit with the steel language of the shaft. A steel minaret asks for a different connection from a concrete one: the core spindle seats onto a flange welded directly to the steel shaft.