[cai]

Hi,

[I'm not sure if this fits in the flooring section, if not, please move it to the right section, thx]

I am working on finishing my basement and am looking up and I see a bunch 1x4 running perpendicular to my floor joists. I originally thought they were there to support the plumbing but then I see they run from wall to wall and don't seem to be supporting anything in most places. Anybody has any idea what they are and what purpose they serve? One of my walls will be framed right where one of these 1x4 are and I want to know if I can safely move these 1x4?

Attached is a picture of one of these 1x4...
thanks.

 

[Bud Cline]

Probably they are there to prevent twist in the I-Joists. Removing them wouldn't be the end of the world unless they were installed for a good reason to begin with. That method isn't necessarily the usual method for preventing twists in floor joists.

They could also be a good beginning for the installation of some types of ceiling materials.

 

[loneframer]

They are there for a reason. With I joists, strapping is required if the bottom of the ceiling is not sheet rocked, or finished in some fashion. Nailing through the joist cords sideways is not allowed, as it will weaken the structure of the joist. Strapping helps to unify the floor and forces the joists to work more as a system, rather than independantly.

 

[Red Squirrel]

I think it is to prevent twisting as mentioned. I have those in my crawlspace as well. My joists are 2x8s. Oddly I don't have any in the basement part but do have smaller pieces nailed from joist to joist in certain areas (no logic, it's just kinda randomized).

With I beam construction like that normally there are metal X braces though. I've also seen wooden X braces.

I suppose it could also make a decent surface for mounting data cabling.

 

[loneframer]

I think it is to prevent twisting as mentioned. I have those in my crawlspace as well. My joists are 2x8s. Oddly I don't have any in the basement part but do have smaller pieces nailed from joist to joist in certain areas (no logic, it's just kinda randomized).

With I beam construction like that normally there are metal X braces though. I've also seen wooden X braces.

I always use wood x-bridging, regardless of type of joist. However, I joists should not be nailed through the side of the flange. I use 16 gauge staples to set mine, to prevent splitting the flange.

I joists in general do not require bridging, but that is dependent on a properly installed ceiling. When there is no finished ceiling, strapping is used to unify the joists.

 

[cai]

I see. They are part of a system!
Moving onto my second question then. Since I need to frame one 11-12' wall perpendicular to the I-beam joist, just about where these 1x4 are. Is it save to move that 1x4 by about 6-10"?

thx

 

[Bud Cline]

The top plate of the new framed wall will replace that portion of the 1X4.

 

[loneframer]

The top plate of the new framed wall will replace that portion of the 1X4.

Yes, this is correct.:thumbsup:

I can't remember the rule of thumb for strapping, but anything 10' or over should have bridging when using conventional lumber. I use the same theory for I joists.

Perpendicular walls will serve the same purpose of the strapping, provided that each joist is properly fastened to the top plate. Two nails, straight up through the bottom will suffice. Be careful when building the wall as well. If you cut your studs too tight, you could disturb the finished flooring above, tile mainly.

 

[Gary in WA]

The lateral bracing is to prevent over-turning because of the cantilever loads or called out by the Engineer. Installed at 8’ maximum and 1/3 the span, page #10; http://www.ilevel.com/literature/TJ-4000.pdf
Moving it would be fine though I would not substitute the new wall for it. The strapping is probably continuous to perimeters; the wall would need to tie to both side of strapping by adding short pieces (strapping) with laps. Idea is no unfastened joists.

Solid wood joists, only bigger than 2x12 required at 8’ apart; http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_5_sec002_par026.htm

Gary