Metal Roofs - Traditional and Modern Explorations

I consider myself a modernist but I must confess, in my younger years I had a great love of all things old. I loved the grand stone-clad buildings and the intricate detailing of a column, corbel and lintel. Through the years my focus slowly shifted to modern work and design but that first love was always hidden away inside me somewhere.

Once I finished architecture school and started working, I made a move to Montreal and while there I was fortunate to work with a firm that specialized in historical restoration, Fournier Gersovitz et Moss Associés (FGMAA). It was here that this inner love of historical buildings, construction methods and materials was reawakened. During my time at FGMAA I was involved in numerous restoration projects which usually meant I was out in the field; up on a roof or hanging off the side of a building while various trades either took apart a façade or roof, or else were busily reinstalling or doing a repair. It was a fantastic experience and I learned intimately about the craft that goes into making these types of buildings a reality.

There were two projects I worked on at FGMAA that remain foremost in my mind and probably had the biggest influence on me, one due to its sheer size and complexity, the other because of its details. The first is la Fondation Daniel Langlois, a restoration of the original Port Authority building in old Montreal. The project was well along when I came aboard, but I quickly learned much of its history and was fortunate to be involved in some of the site coordination and inspections. The original intent was a minor restoration of the building but during early work a fire broke out that destroyed much of the interior, most of the roof and all the cupola. 

Archival photo of the original building     -     Photo of building after fire

The client took the bold step of deciding to completely restore the building to its original glory as well as enlarging it with a pool building at the rear. This meant archived photos, remnants from the fire and other sources had to be studied in order to rebuild what had been destroyed. The difficulty of the restoration was that in order to recreate some of the work, builders had to source out from long-retired masons and metal workers who knew how to build walls in the old manner, with structural masonry. This means rather than having a typical steel stud wall in front of which a stone cladding is set, the whole wall would be solid masonry and would support the floors above. It was decided that the pool addition would also be built in the same manner. The retired masons set themselves up onsite and essentially taught the younger masons how to construct the wall.

The project also included a great deal of highly detailed metal work on the upper walls and roof including the new cupola. Historically, the benefit of the malleability of metals has made them easy to work with, and because of their impervious nature they are perfect for shedding water. Metalwork has even been used to reinterpret stonework because the same effects can be created quicker and easier than carving out hard stone. Metal can be hammered over top wood framing or carvings to recreate their intricate detail then replicated in a fraction of the time it would take to hand-carve stone. The photos below illustrate how this technique and material was used to exceptional success on the building.

Metal window arch before installation     -     Metal detailing at roof level

Cupola framework being craned into position     -     Finished building

The other project I was involved in was a small chalet in Montebello. Again, it was an existing building but this time a much smaller Swiss style chalet that was to be extensively remodeled and restored. The two most interesting aspects of this small chalet was the use of exposed wood beams and wood detailing throughout the house, and the introduction of a standing seam copper roof. Copper is a beautiful material and has the capability of imparting a magical, ethereal quality to buildings. It can be coated to retain its lustrous finish or left to weather and develop its own patina. The typical greenish tone that develops is a factor of humidity, temperature and chemical interaction (usually pollutants help the process along). Not long after the roof was installed I was surprised to arrive on site for an inspection and find that the roof had already turned completely black. This would slowly change to the more familiar green tone.

View of renovated Chalet     -     Copper clad chimney with detailing

For such a small roof there was still a great deal of fine detailing that was incorporated into the design, giving me a good cross section of techniques and experience to draw from in future projects. Inside the house we also constructed a feature wall in the master bathroom of copper fish scale shingles. Various techniques can be used to create paneling for a copper surface such as the fish scale and standing seam techniques that allow smaller sections of metal to be joined together in a watertight assembly while also imparting a texture to the building. The house also featured various metal details such as copper birds on the roof ridge and imprinted flower motifs on the chimney.

Fish scale copper shingle clad wall in master bathroom     -     New clear storey or Lucarne with copper roof 

While I loved my experience with the stone work, I think from these two projects the thing that intrigued me the most was the potential of the metals. To me it seemed to be a material that had more room for exploration, and the potential of taking the historical techniques and installation methods and reinterpreting them for modern projects, I think provides great intrigue.

While the benefit of metal is its pliability this is also its limiting factor in that it cannot be used in large flat panels as it will start to “oil can” or buckle. To maintain its strength and rigidity it needs to be bent to create stiffeners running perpendicular to the main body of the panel. As a result, the general aesthetic of metal is that it will always be composed of a series of panels fastened together in some format. Traditionally there have been many different configurations including tiles and scales as mentioned above, and panels, linked together with various bends either at the back of the panel or exposed upright on the outer face. These upright bends are referred to as the standing seams of the panels and it’s these that give the panels rigidity.

Various images of metal roofs and cladding techniques possible (as taken from Rheinzink )

 For the house that we design on GregoryRoad, I think pretty much from the beginning I had in my head that I wanted to use metal roofing and I think that decision started to influence the remainder of the design decisions helping to shape the design. I spent some time exploring how the roof plane might undulate and bend to open the roof to light and express the functions that were contained below, but in the end the roof became a very simple form that I think allows the volumes of the house stand out as the key elements of the composition and design.

Early sketch and roof study     -     Sketch close to design completion

While the house is quite simple in its form the roof, both with the metal and through the exposed rafter tails (the wood members that are exposed on the underside of the roof), provides a rhythm and detail that softens the design and gives drama. By leaving the rafter tails exposed rather than cladding them is typically done, the structure is exposed both providing an understanding and honesty of how the home is built as well as celebrating it. We were able, for the most part to match of the seams of the roof to the rafter tails so that the two work together visually providing the main rhythm to the house.

Installation of metal roof

The clean lines of the standing seam roof work well with the smoothness of the wood Silva Panels and the smooth stucco. The reflective quality of the metal also provides a changing mood to the house depending on the quality of light. It can appear very bright or quite dark depending on the light of the sun and the metal will also reflect colour and tones that might be in the sky, giving the roof a life of its own. It was a good experiment and I am happy with the results, but of course I look forward to pushing it further the next chance I get.

Completed house showing metal roof, rafter tails and wood panelling used on walls