Editor’s note: Welcome to the Brownstone Boys Reno, a reader renovation diary about renovating a brownstone in Bed Stuy. See the first one here. They also blog at www.thebrownstoneboys.com. In many ...

Q. This week: My house is about 70 years old and the floors on the first story shake when someone walks on them. The problem, I think, is that the floor joists are too narrow. They're only 7.5 inches ...

Building codes governing framed floors include an allowance for sagging, which sounds bad. But the allowable limit is 1/360 of the span, which isn’t much. Spread over a 45-foot-long joist — if you ...