Canadian Consulting Engineer

Feature

A Hindu Temple in Toronto

Anyone travelling along busy Highway 427 northwest of Toronto is struck by an almost surreal sight. Across the flat and industrial landscape, a few hundred metres to the east of the highway near Finch...





Anyone travelling along busy Highway 427 northwest of Toronto is struck by an almost surreal sight. Across the flat and industrial landscape, a few hundred metres to the east of the highway near Finch Avenue West, sits a gleaming new Hindu temple. The white stone “mandir” is intricately designed and crafted in the traditional Indian manner, complete with domed roofs and tapered towers, and a gigantic stone staircase up to a wide portico.

Officially opened by Prime Minister Stephen Harper in July, the temple and another prayer hall next door form the BAPS Shri Swaminarayan Mandir centre. The centre is a focus for the 190,300 Hindus in Toronto, but also a point of reference for non-Hindus since the buildings are open to the public for viewing.

The stone temple was constructed for a cost of $40 million, with no public funding. The upper floor is a prayer hall, an ornate circular space of columns and domes, surrounded by niches that hold Hindu deities and BAPS dignitaries. The lower level holds the Indo-Canadian Museum of Cultural Heritage.

The Toronto mandir is similar to other BAPS temples built recently in London, U.K., Nairobi, Kenya and Chicago. BAPS stands for Bochasanwasi Shri Akshar Puroshottam Swaminarayan Sanstha, a “socio-spiritual” Hindu organization established 100 years ago.

The architects and structural engineer describe their work on this unique project.– BP

SHRI SWAMINARAYAN MANDIR, TORONTO

We were instructed by His Holiness, Pramukh Swami Maharaj, leader of the BAPS organization, that the mandir must be designed as a typical Hindu temple based on the traditional design and construction of a “Sompura” carried out 500 years ago in India.

This method of construction means no structural or reinforcing steel can be used. The idea is to avoid having a magnetic field. When you enter this prayer hall, since there is no magnetic field, it is easy to concentrate for meditation.

After studying the existing temples in India and their construction methods, we found out that the stone slabs could only span 8 feet. All the column spacing had to be designed to 8-feet centre-to-centre. The slabs quarried were 3″ to 4″ thick and uneven.

The stone not only had to withstand the Toronto freeze-thaw cycle, but also had to meet the aesthetic needs and be cost effective. George Papadopoulos and a BAPS engineer visited various countries including Turkey, Italy and Greece to find the right stone. They visited strip quarries, climbing mountains in sweltering temperatures of 40C some days, and finally selected stone from Turkey.

In November 2005, the stone was shipped from Turkey to several workshops in India for precision cutting, dressing and carving. Over 2,000 stone carvers were engaged in the state of Rajasthan for the project.

From India, the carved stone — all 24,000 pieces — was shipped back to Toronto in 300 containers for assembly. Each stone piece was fully bar coded to ensure that the pieces could be assembled on site without the construction team having to solve a giant jigsaw puzzle.

Over 100 craftsmen were brought to Toronto from India to construct the temple. They had to be trained to think in the Canadian way. Several local trades were also used.

The temple was completed in 18 working months. As the stonework could not be carried on in sub-zero temperatures, the construction site was completely closed during the winter months of 2005 and 2006.

Meeting old traditions and new codes

At every turn, we had to invent a way of constructing something that respected the traditional construction but was compatible with Canadian building codes and technology today. We also had the formidable task of ensuring that the treasured delicate carvings inside remain safe and dry. And since this stone building is supposed to last more than 1000 years, we had to ensure that all the systems could be replaced when necessary in the future.

The outside walls, for example, had to meet the Ontario Building Code R-value. The stone was dressed only in the front, while the rear part was very rough and posed many problems regarding keeping the air space and providing insulation and waterproofing.

A service floor was provided under the entire building, and all the consultants had to find a way to bring their services such as heating and ventilating ducts into the main upper levels. To do this, small shafts were threaded through the exterior walls. Inside the prayer hall, the lighting conduits had to be hidden out of sight behind the carvings, and a hydronic heating system was provided under the marble floor.

Stone slab on beam

The temple structure is an ancient conventional system of stone slabs supported on stone beams. The stone beams are supported on corbels mounted on stone columns.

The exterior walls consist of stone cladding on the outside of load bearing concrete block wall. These two elements are thermally separated with insulation and a vapour barrier. The two wythes are tied together with stainless steel ties.

The exterior limestone from Turkey had an ultimate compressive strength of 71 MPa. The sandstone used for the slabs, beams, corbels and columns in the lower level was from India and had an ultimate compressive strength of 109 MPa.

The upper floor structure, including the interior and roof domes was finished with Carrera marble from Italy. It has an ultimate compressive strength of 130 MPa.

A very high structural safety design factor of four was used — more that twice the standard requirement. All drawings were prepared on CAD. Shop drawings for every stone piece were also prepared on CAD at 1:1 scale to ensure precision carving and assembly.

Designing and constructing the roof was a special challenge. The use of false work to support the centre dome, which is 24 feet in diameter, 15 feet high and weighs 205 tons, was phenomenal. Carrera marble pieces on the dome’s interior face were assembled over the false work, connected to each other with copper clamps and grouted. Then 4″-6″ of concrete was poured over the dome and then another layer of standard brick was laid over the dome to obtain the required shape. The brick layer was waterproofed and insulated with membrane and rigid insulation. Last, finely carved limestone pieces were placed together as the outer shell.

The building foundation is a 1-metre thick flyash concrete raft that was laid in a single pour without any steel rebars.

A gantry girder spanning 130 feet across, 400 feet long and 75 feet high, large enough to encompass the entire temple building, was used to lift and place the carved stones in position.

Owner: BAPS Shri Swaminarayan Mandir

Structural engineer: Dave Arora, P.Eng., Delta Engineering Services, Markham, Ont.

Architect: Papadopoulos and Pradhan Architects, Toronto (Arun Pradhan, George Papadopoulos)

Project manager: Naren Sachdev, BAPS Development

General contractor: BAPS

Mechanical: Nitsch & Associates

Electrical: Neil Patel Engineering

Other key players: Davroc Testing Laboratories (stone testing), Dr. Mehta, University of Californa at Berkeley (concrete consultation)