It is not unusual for our crews to be working on a fifteen-year-old home one day and a 125-year-old home the next day. What are the differences in working on these vastly divergent homes?
Balloon framing was the first style of wood framing which would utilize long vertical two by fours for the exterior walls. These long studs would extend uninterrupted from the sill on top of the foundation all the way up to the roof framing. You could drop a penny from the attic to the basement in a wall cavity. It started being replaced prior to World War II with a style of framing called platform framing.
What are some of the advantages of balloon framing? The first is increased wind load strength. The roof structure is tied to the foundation by the continuous studs. Balloon frame structures have less settling or shrinkage than platform framing. Wood tends not to shrink along its length, it shrinks in the width of each framing member.
What are some of the disadvantages of balloon framing? The biggest disadvantage is that it creates a continuous void which will allow fires to spread easily from one floor to the next.
To put out fires in a home that has been balloon framed, firefighters often must open a huge portion of the exterior of the home which causes significant damage. When we are working on a balloon framed home, we always install “fire stops”. That is a piece of wood placed inside of the framing horizontally and fire sealed to prevent air movement in case of a fire. The building inspectors will mandate that “fire stops” are in place.
I am currently renovating my master bathroom and I was able to quickly replace the drain, water supply lines, and electrical feeds for the bathroom because they ran through a continuous cavity created by the balloon framing.
Platform framing involves a large amount of lumber which is run horizontally in between wall structures. In these framed floor areas, we will see a substantial amount of shrinkage. If the floor framing on a platform home is constructed from 2 x 12s, it is not unusual for that framing member to shrink ¼ inch during the first heating season after construction. A newly constructed home can shrink an entire inch causing much cracking.