Ceiling joists are usually installed either 16 or 24 inches on center which means roughly 16 or 24 inches apart.
Floor joist orientation.
But larger is not always better when builders are constructing a home or adding a room addition.
Endgroup carl witthoft jan 29 16 at 13 36 begingroup carlwitthoft.
Ceiling joists can run in any direction and it is often very difficult to tell which way they are running without being able to seem them.
The floor joists may run parallel to the short dimension at the floor level but at the roof level the short dimension is the opposite direction.
It is most common for them to run across the short dimension a room but this.
Common sense tells you that large floor joists can carry more load and spacing joists closer together also increases the load bearing capacity of a floor.
You can never ever ever notch or bore through the top or bottom flange or chord.
The roof is modern or unique such as a single sloped roof flat roof or a unique overhang.
The more material you can put away from the force the less of an impact that force has on the material is correct but the rest of it seems a bit off the.
In fact most have little perforated knockout holes that can be punched out with the swing of a hammer.
There are often visual clues.
Notching wood and boring rules engineered i beam rules.
How to find a ceiling joist.
The extra two inches of vertical distance when a floor is framed with 2 x 10 joists rather than 2 x 12s can be quite important for example.
Holes anywhere in the web.