ONETIME- Big dig: Why we fired that subcontractor
One time, we had to extensively remodel a fraternity house, which involved retrofitting a 40-foot-long basement dining hall in this historical building that didn't have a basement. The short schedule further complicated matters: we could only work during the summer while the resident students were gone.
We hired a subcontractor to do the excavation and the shoring for the basement, and they said that they had lots of experience in this sort of work.
The Monday they began working, my brother, who was supervising, soon started expressing concern about some of their practices. He pointed out that they were digging sheer to the building, ignoring the angle of repose and not using any shoring. Over the next couple of days, he continued to question them about his concerns, and they continued to reassure him that they knew what they were doing.
Whey they finished digging on that Thursday, they had a hole 17 feet deep alongside this building, which is a very deep hole.
That night, there was a massive cave-in that threatened a twelve-inch water main nearby. The city condemned the building, and forced us to fill the excavation in with gravel to stabilize it and the cut on the street side to avoid further damage.
We let the subcontractor go, and began an intensive summer of trying to clean up their mess. The project was far more difficult than it would have been originally. Among many other problems, hairline cracks had appeared in this historical building, and the brick had to be preserved. We completed the project on schedule, though.
Dealing with historical or older buildings involves many considerations. If a building was built in the last few decades, you have a reasonably good idea of how it was built. However, when you get into a funky, much older building, which has been added-on to repeatedly and has had walls taken out many times during countless remodelings and was built using long-antiquated techniques (like knob-and-tube wiring, or asbestos insulation)– it can make it very tricky.
We frequently uncover a compromised structure in old buildings. It's not unusual to find so much inadequate or missing framing that you wonder how the building has remained standing. And, as was true with the fraternity house, there are often aspects of older buildings that owners love and want preserved, and this has to be balanced against the remedies for structural problems.