A wooden balcony collapsed at an apartment building in Berkeley, California due to dry rot caused by improper waterproofing and lack of ventilation. The balcony's wooden frame deteriorated over time as moisture was able to enter and become trapped without means for drainage or airflow. Contributing factors included issues with the balcony's design, materials used, construction practices, lack of maintenance inspections, and building codes not being followed. Proper treatment and selection of durable materials, inclusion of ventilation, and periodic inspections may have prevented the collapse.
Green building construction and materials aayush kumar
Balcony collapse at Library Gardens Apartments
1. Niall Rabbitte
Student ID: 13369116
Balcony collapse at Library Gardens Apartments, Berkeley, California
The balcony was a cantilever design consisting of wooden joists and wooden sheeting frame. The
wooden frame had a bitumen sheeting and concrete floor over. Improper waterproofing led to
water ingress to the timber deck. The moisture with a lack of ventilation created an ideal
environment for dry rot. Timber affected by dry rot is brittle with cracks across the grain.
The deck was designed to carry at least 60Lbs per square foot[1]
. The area of the deck was 24 square
feet[2]
.This means the deck (as designed) should have carried 1440Lbs safely. The timber had
deteriorated due to rot leaving it severely weakened.
The City of Berkeley should have regulation on materials and maintenance schedules.
The joists were shrouded so not to allow for inspection or drainage. The designer should have
allowed for access for maintenance. The designer should also have included vents. The engineer who
signed the drawings should have pointed these faults out.
The planning authority should not have passed the design of the balcony without access to the
wooden joists. They also should have pointed out the lack of ventilation.
There is a possibility that the builder’s supplier may have supplied below standard or unsuitable
material for the balcony.
The building contractor, Segue Construction used a soft wood which had not been properly treated
with wood preservative leaving the timber joists prone to rot. The contractor should have used
properly treated timber. Alternatively a more durable timber or suitable metal could have been
used.
The balconies should have been periodically inspected for deterioration. The owner is responsible
for ensuring the safety of the building.
[1] Minimum Design Loads for Buildings and Other Structures Revision of ASCE 7-98
[2] http://www.librarygardens.com
![Niall Rabbitte
Student ID: 13369116
Balcony collapse at Library Gardens Apartments, Berkeley, California
The balcony was a cantilever design consisting of wooden joists and wooden sheeting frame. The
wooden frame had a bitumen sheeting and concrete floor over. Improper waterproofing led to
water ingress to the timber deck. The moisture with a lack of ventilation created an ideal
environment for dry rot. Timber affected by dry rot is brittle with cracks across the grain.
The deck was designed to carry at least 60Lbs per square foot[1]
. The area of the deck was 24 square
feet[2]
.This means the deck (as designed) should have carried 1440Lbs safely. The timber had
deteriorated due to rot leaving it severely weakened.
The City of Berkeley should have regulation on materials and maintenance schedules.
The joists were shrouded so not to allow for inspection or drainage. The designer should have
allowed for access for maintenance. The designer should also have included vents. The engineer who
signed the drawings should have pointed these faults out.
The planning authority should not have passed the design of the balcony without access to the
wooden joists. They also should have pointed out the lack of ventilation.
There is a possibility that the builder’s supplier may have supplied below standard or unsuitable
material for the balcony.
The building contractor, Segue Construction used a soft wood which had not been properly treated
with wood preservative leaving the timber joists prone to rot. The contractor should have used
properly treated timber. Alternatively a more durable timber or suitable metal could have been
used.
The balconies should have been periodically inspected for deterioration. The owner is responsible
for ensuring the safety of the building.
[1] Minimum Design Loads for Buildings and Other Structures Revision of ASCE 7-98
[2] http://www.librarygardens.com](https://image.slidesharecdn.com/03d6c968-b4db-4913-ae73-8838528a18ca-160105215020/85/Balcony-collapse-at-Library-Gardens-Apartments-1-320.jpg)
