strongbacks

[*Guest]

In the attic of my 1-story frame house there's a strongwall that's obstructing a potential storage area. It's L-shaped (1x6 vertical, 2x4 flat). It runs down the centerline of a 9x18 ft room.

Are strongbacks necessary? I've found very little mention of them in home building books. If I need one, can I replace the 1x6 by an on-edge 2x4?

[*Wgoodrich]

In my area they are called STIFFLEGS or STIFFBACK.

Building is designed using triangles for strength and to hold a structure together limiting movements. The bigger the triangle the more likely something wll move. Often times a "stifflegs are installed in an attempt to reduce the size of the triangle of the ceiling joists and rafters making a big triangle and hte stiffleg making that one big triangle to be two small triangles. This stiffleg would normally be installed over a bearing wall located below the ceiling joist. This stiff leg making a big triangle into two small triangle significantly increases the strength of the structural triangle designs.

A stiffback is normally installed on top of a cieling joist that makes a long span for the ceiling. This stiffback allows for all the ceiling joists to remain even allowing the ceiling not to have waves like an ocean in the finished cieling installed on the bottom side of the ceiling joists. The stiffback pulls all the ceiling joists to be even on the top limiting the up and down uneven joists for your ceiling to be mounted to. The strength of the stiffback being a 2x4 nailed flat to the ceiling joists and to the side of the 1x6 standing on edge is the distance of 5 1/2" from edge to edge of the 1x6. The 2x4 only provides for a straight run of the 1x6 adding strength to the 1x6 from bending or waving as it runs the length of your attic.

In your case if you added the 2x4 by nailing to the verticle of the 1x6 without removing the 1x6 then cut off the excess of the 1x6 sticking above the 2x4 your added then yes. Otherwise I would not remove this 1x6. If you remove that 1x6 then nail on the 2x4 chances are you will see a wave or two in your ceiling or even some cracks in the ceiling will appear becuase you removed the 1x6 allowing the ceiling joists to shift defeating the reason for the stiff back.

Be careful storing much load up there. Chances are your ceiling joists were spanned without storage expected thus not being rated for the storage load you may be thinking of adding to that ceiling joist. You probably could store some light stuff up there but remember your ceiling joists most likely were not sized expecting that storage load to be applied to them.

Hope this didn't get too confusing and maybe helped

Wg