HOW TO DETAIL IRON BALCONIES AND GALLERIES IN THE VIEUX CARRE OF NEW ORLEANS

I have had numerous opportunities to work on renovations in the Vieux Carre, many of which required the repair, restoration or construction of a balcony or gallery.  Before describing the way I detail balconies and galleries, it is important to clear up the lexicon.  The terms “balcony” and “gallery” are often used interchangeably, and there can be considerable confusion as to what one is referring to.  A balcony is a simple structure that cantilevers from a building’s façade, providing an upper level outdoor space that is surrounded by a railing.  A gallery is a more complex structure that may be either a cantilever or a simply supported structure that includes columns or railing panels connecting one or more levels or roof canopies.    A cantilevered gallery is one where the columns are omitted between the upper level and the street or courtyard level below.  The columns or railing panels, which extend from the cantilevered second level up to the roof canopy or level above, do not provide any structural role except to laterally support the railings.  The easiest way to remember the distinction is to remember that any structure where there are columns, whether the columns extend all the way to the ground or not, is a gallery.  Anything else is a balcony.  If one were presenting a project in front of the Vieux Carre Commission, it is important that the terms be used correctly to avoid confusing members on the commission and the architectural review board (ARC).

 

This post is only going to describe balconies and galleries made of iron; a later post will describe balconies and galleries built of wood. 

 

The typical townhouses of the Vieux Carre usually consists of a main building that is two to three stories high that fronts onto the street.  A servants’ wing either extends perpendicularly from the back of the main building is at the rear of the property facing back to the main building.  The gallery of a servants’ wing extends the length of the wing and has a stair at the far end and is used as a second floor exterior corridor.  The gallery of the servants’ wing is built of wood to be more utilitarian.  The balcony or gallery of the rear elevation of the main house may also be built of wood, but generally the iron railings and balconies in the Vieux Carre are reserved for the more prominent street elevations.

 

The building structures in the Vieux Carre are either all wood frame construction, or have wood framed floors and walls supported onto load bearing masonry walls.  If one is to construct a balcony or cantilevered gallery, the cantilevered structure must extend into floor structure approximately the same distance that the balcony or cantilevered gallery projects to provide adequate support.  A simply supported gallery is usually attached to the exterior façade and may not need to extend into the floor structure since it consists of simply supported beams or outriggers.

 

The framing of galleries and balconies consists of steel outriggers that run perpendicular to the building façade, and are made from steel plates, usually about 4 inches deep by 1/2 wide, but these dimensions can vary depending on the structural loads.  Older galleries and balconies had outriggers that were dimensionally smaller in section; attempting to replicate similar structures with smaller sections may result in a structure that is not capable of supporting the live loads required by today’s building codes.  In fact, during Mardi Gras and events where a large crowd can be expected to accumulate on the balconies or galleries, many building owners of older buildings provide temporary shoring to provide additional support, and to prevent collapse.  This is especially true of cantilevered structures.  The spacing of the outriggers is usually 32 inches on center.  If the structure is a cantilever and must extend into the floor structure, this spacing allows for the outriggers to attach to every other floor joist, assuming that the floor joists are spaced 16 inches on center, which is usually the case, and assuming the floor joists are running in the same direction as the outriggers.  Often times the floor joists are running perpendicular to the outriggers (parallel to the building façade).  In these instances a slotted hole within the centroid of the first two or three joists can be made to allow the outrigger to pass through.  The slotted hole should occur at about the middle third of the joists’ depth to avoid reducing their load carrying capacity.  Steel clip angles can attach the outriggers to each joist as it passes through.

 

On older balconies, the iron outriggers were forged into a hook or eye that allowed a vertical iron railing post to be inserted.  The outriggers of a balcony or cantilevered gallery were independent of each other but were connected by the ornamental railing above.  Over time, this resulted in some of the outriggers sagging at different rates, resulting in a balcony or gallery edge that undulates up and down slightly.  Because it is not practical to fabricate the outriggers with the hooked ends, and to prevent the undulating sagging of the balcony edge, I always provide a steel plate beam that is welded to the ends of all the outriggers.  This provides redundancy in the structure and prevents a weakened outrigger from sagging more than any of the other outriggers.

 

The outriggers should also be slightly pitched, usually 1/4 inch per foot away from the building to allow water to run off the surface of the gallery or balcony.  If the outriggers need to extend into the building as needed for cantilevers, it is important to verify that the outriggers are still able to pass through the slotted holes of the joists, otherwise the outriggers will need to be spliced with a level section extending inside.

 

Sitting on top of the outriggers are wood purlins that are equally spaced, but usually no more than 18 inches apart.  A 3 foot balcony, for example, would have a purlin at or near the façade, one at the outer edge just behind the steel plate beam connecting the outriggers, and one in the center between the two.  The wood purlins are about 3 inches to 4 inches wide by 3 inches to 3-1/2 inches deep, and sometimes have a beaded profile routed into the bottom corners.  (Once again, older balconies and galleries often had smaller purlins.)  The purlins are notched to sit atop each outrigger.  Often times a steel clip angle is used to connect the wood purlins to the outriggers, but I prefer to have 1/4 inch threaded studs welded to the top edge of the outriggers where each purlin is required.  The purlins are drilled with holes to fasten them to the threaded rods with countersunk nuts.

 

Wood blocking is bolted to the face of the steel plate beam that runs across the front of the balcony or gallery edge to provide a nailing surface for the wood fascia.  Some balconies and galleries have radiused corners where they wrap around the corner.  In these instances several small blocks of wood are used, or the blocking is kerfed on its back edge to allow the board to bend into the desired radius.

 

The balcony or gallery is decked with tongue and grooved decking nailed to the tops of the purlins; the decking extends over the edge of the front fascia approximately 1-1/2 inches where it is sawed off.  A piece of wood trim, similar to a base cap turned upside down is installed under the extended edge of the decking.  If the balcony or gallery is not waterproofed, water drips through the decking which will eventually deteriorate within 10 to 15 years.  Many balconies and galleries in the Vieux Carre are not waterproofed; the older ones that were, had a stretched canvas membrane applied to the top surface to provide somewhat of a waterproof membrane.  For modern construction, I would recommend that a 1/4 inch thick plywood underlayment be installed over the decking and a traffic coating such as Dex-O-Tex Elastatex 500 be applied over the underlayment, along with edge flashing installed at the balcony or gallery edge, and counter flashing installed at the building. 

 

The attached drawing shows a detailed section of a typical cantilevered balcony and a typical gallery.

 

The photo captions are as follows: 

 

1.       A close up of an older cantilevered gallery showing the outriggers with hooked ends.  The fascia is missing, so the construction is more visible.

2.       A balcony.

3.       A cantilevered gallery.  This is the same gallery shown in the first photo.

4.       A simple column supported gallery.  This is a recently built gallery that I designed about 10 years ago.

5.       Another gallery with a third level balcony.  The balcony was recently built just over 10 years ago, and was also one that I had designed.

 

 

 

Reduced_balcony-galleries_001Reduced_balcony-galleries_002Reduced_balcony-galleries_003Reduced_balcony-galleries_004Reduced_balcony-galleries_005

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