metal rafters

[paulmars]

I have four sagging rafters in garage in my 1952 home. They are 2x6 and all side by side. All four have knots in about the same location, resulting in
sagging. I got 4 2x6s to sister these, but that's a lot of weight to add
side by side. So, Im thinking of using angle iron, as least for two of them.

Thoughts?

4/12 pitch. 12.5' rafter length. Single layer of shingles, which will be
removed and replaced soon. House has no trusses or rafter ties. I will be
adding a few rafter and collar ties.

tks,
pa

 

[tony1851]

Deflection might be the critical issue here, if the existing 2x6s are not in good shape.
To reduce deflection on that span, you would need fairly hefty steel angle, which defeats the object.
Why not just sister each with something like 2x8? You can cut down the heel where it meets the wall, to match the 2x6s, and it won't affect the stress or deflection.
And probably easier and cheaper than angle.