The city building inspector in Concord, New Hampshire, suspects faulty connections between the rafters and the attic joists caused the roof of a two-story Colonial to slide off last week.Click to ...

The city building inspector in Concord, New Hampshire, suspects faulty connections between the rafters and the attic joists caused the roof of a two-story Colonial to slide off last week.

Floor joists are sawed from logs. They often have inconsistent crowns to them. A crown is a hump in the floor joist. Humps and floor tile don’t play well together.

A standard I-joist is normally 8 feet to 24 feet in length, but I have seen much longer I-joists. With longer I-joists, a center support beam or header will be needed to prevent "bouncing" floors.