Please help with terminology!


Old 01-15-05, 11:01 AM
Visiting Guest
Posts: n/a
Please help with terminology!

Hello! This is my first post and I am hoping someone can explain some terms I have run across in reading these "attic conversion" posts (for over an hour!)

I have a 1920 1 1/2-story home. The second floor of the home (accessed by permanent stairs off the back hall) has two finished bedrooms which seem to have been used since at least the 1940's. I am trying to establish whether this is a true "second floor" with a strong floor system (it seems very strong walking on it) or an attic conversion that may need some additional support. I believe the floor joists under this "second floor" are 2x6 (I also know there are "bridges" (?) between these joists). The house is long and narrow (about 22' feet wide from one exterior wall to the other) with one main load-bearing wall down the center of the first floor and many partition rooms on the first floor.

My question (after reading these attic conversion posts) is what is the meaning of "on center" and "span" with regard to the floor joists? How do I measure these?

Thank you in advance for your assistance!!!

I moved this from attics so you would recieve proper terminology answers.

Last edited by majakdragon; 01-15-05 at 12:53 PM.
Sponsored Links
Old 01-15-05, 02:16 PM
Join Date: Oct 2004
Location: New Jersey
Posts: 1,132
The span is how far the joist spans from beginning edge of unsupport to the next support. For example, on a 2x8x12 is spanning frome one wall to another, both made of 2x4's. The span is 11'5" because each 2x4 making the top plate of the wall is 3 1/2" wide. The spacing is how far apart the joists or studs as measured from the center of one stud to the center of the next. 16" oc would leave 14 1/2" between. Common spacing is 16. 19.2 and 24" oc, each of which will evenly space 8' long panels across them.
Old 01-15-05, 03:49 PM
Visiting Guest
Posts: n/a
Thank you!

Thank you for answering. That was the impression I had gotten from my reading, but I wanted to check.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes