Any idea what this means?

[Bkeepr]

Feedback from a realtor who viewed Mom’s house said the garage roof is sagging (it has appeared to sag for years). He wrote the following to my realtor; I am over an hour away so am not driving down there today, but I don’t understand the comment “they did a sister”:

“It is really evident over the garage and upon inspection of the garage it seems the garage door installation may be causing it. I see they did a sister on a split rafter there. Take a look at it.”

Thanks

[PHPaul]

A "sister" is when you nail a second timber (2x4, 2x6 etc) to the side of an existing timber, usually a rafter or joist. Either to add strength or to repair a cracked timber.

[Bkeepr]

Got it, thank you.

Guess I’ll have to drive down tomorrow to see what they are talking about.