Francis Brannigan

®	June-July 2004

Balloon-frame construction started in 1833. The architect of St. Mary’s Church in Chicago hit upon the idea of fabricating a wall of ordinary studs, nailing it together. Inexpensive machine-made nails had become available. This made it possible to throw up the entire wall at once without the skilled labor necessary to do the cutting and framing required for post-and-frame construction. The type of construction was derided by many who said it was so light that it was like a balloon. Unfortunately, as will be seen, it can be compared to a balloon in another way. In any event, balloon-frame construction became an almost universal construction method for multi-story wooden buildings until the middle of the 20^th century.

In a balloon-frame building, the studs run two or more stories high from the foundation to the eave line. At the floor line, a horizontal board called a ribbon board is nailed to the studs. The joists rest on the ribbon board. The channels between the studs may be open from the cellar to the attic, and the joist channels (space between the joists) are open to the stud channels. Thus, fire can spread through all the interconnected spaces from cellar to attic and across the ceiling. Present-day methods may use firestopping, but earlier constructions, when many of these buildings were built, did not.

The interconnected voids can be considered to be one big balloon. The author saw this confirmed at a fire in an old balloon-frame house. There was a heavy fire in the porch ceiling. Each time it was hit with a fog stream, the fire ballooned out at the rear of the building.

When balloon-frame buildings are remodeled, fire stopping may or may not be installed. Installing fire stopping in an old building is very costly. In one case an historic balloon-frame college building was fully rehabilitated. Even though sprinklers were installed, fire could have raced through the voids if they were not firestopped. The final cost was about two-thirds of the cost of a new building.

Until recently it was reasonable to assume that any wooden building built before 1940 and more than one-story high was probably of balloon-frame construction. Later buildings used platform-frame construction. Recently, however, the Victorian-style construction has come back into favor, and expensive multi-story platform-frame suburban homes are being built to look like one hundred year-old farmhouses.

The book Building Construction recommends balloon-frame construction as superior to platform frame for masonry-veneer houses. Shrinkage of the wooden building could damage the brick veneer. The smaller vertical shrinkage potential associated with a balloon-framed structure contrasts with greater horizontal shrinkage potential of platform frame construction.

Two six-story brick-veneer apartment houses recently built in an Ohio suburb were of balloon-frame construction. Studs were spliced to achieve the required height. The apartment houses had many deficiencies and presented a major fire hazard. The fire chief fought successfully to have them torn down before they were ever occupied.

Interior Walls: Masonry buildings with spans greater than 25 feet must have interior bearing walls. In older buildings these walls are usually of balloon-frame construction unless made of masonry. Interior masonry walls can be distinguished from wooden interior walls by their greater thickness. Large wooden buildings also must have interior bearing walls, which usually are of balloon-frame construction in older buildings.

Fires in Balloon-frame Buildings: A chief officer, who was a student in a fire science course, described a fire which the first-due company reported as “outside rubbish.” The officer ordered some of the siding removed and found fire in the walls. Shortly thereafter, another officer reported that an upstairs bedroom on the opposite side of the house was untenable, even though no fire was showing. The fire had quickly crossed over through the joist channels and had literally surrounded the bedroom. A good fight saved the building, but the damage was extensive.

Los Angeles City Fire Department Battalion Chief John Mittendorf provides an excellent discussion of the hazards of fire in a large balloon-frame “queen Anne” building in which the roof collapsed and a fire fighter escaped with only minor injuries.

Another California fire demonstrates that sometimes even sprinklers cannot always protect balloon-frame structures. An incendiary trash fire, against an exterior wall of the Victorian building, penetrated into void spaces. Responding fire fighters checked for extension but found nothing. Fire broke out four hours later. Much structural damage occurred before the sprinklers activated on fire which broke out from the voids.

	This Montana mining town dance hall shows the vertical voids open to the floor voids, a characteristic of balloon-frame construction. The interior is “one big balloon.”
	Pennsylvania fire fighters worked from the outside to cut off this balloon-frame building fire, thus minimizing interior damage.

When a fire has entered the inner structure of a balloon-frame building, it can spread to every part of the building in all directions. Investigate all parts of the building immediately. Be aware of the potential for intense fire buildup in void spaces. Don’t wait for the smoke, heat and fire to make conditions untenable before you decide to examine the attic. Fire moving up or down through exterior stud channels can often best be stopped by removing siding from the outside at the second floor line, and eave and foundation lines.

The author was recently lecturing in Pennsylvania, where fire officers described a fire in a balloon-frame wall. They had followed the suggestion given above, to open the wall from the exterior, rather than the interior, and stopped the fire. If they had made a conventional inside attack, they might have lost the building.

The problem with an attack limited to inside operations is that fire moves up through many stud channels. As soon as the first channel is opened, the situation becomes obscured with smoke and steam. It is easy to miss a channel, and the fire may get away. Many fire departments today lack the bent swivel tip which was used on the old controlling nozzle. With this swivel tip, the fire fighter could quickly give it a dash up and down the channel. This is not as easily done with today’s equipment.

Fire burning in balloon frame walls destroys the structural integrity of the building. Collapse is a serious threat. Fires in balloon-frame buildings should be observed from the exterior, by an officer specifically assigned to that function, and positioned far enough away to see the entire building. This officer should watch for signs of fire spread — heavy volumes of smoke pushing out from voids in the building, as well as intense heat buildup and structural failure, which may not be apparent from close range. Chief Donald Loeb discusses fire fighting in the most common type — the balloon-frame 2½ -story dwelling.