I asked a question a few weeks ago about a diagonal crack in one of our main support beams in our basement. With your advise I ended up have a structural engineer come take a look at it and he recommends screwing another 2x10 to it so it doesn’t crack any further.

Is this something I would be able to do myself? Would I have to have a someone come out to do it since that’s a loan bearing beam? I’m not a pro by any means but this seems so simple. I’m not sure the best way to go about this since the framing for the wall butts up against that beam. How would you tackle this? Should the framing for that wall be moved so the entire beam can be sistered?

I put a few photos from the report the structural engineer gave.

enter image description here

enter image description here

enter image description here

enter image description here

  • Don’t put the screws in a straight line have them staggered that steel Jack is supporting the load to the one side and really if you don’t span either side by ~2x+ the crack length is it going to really do anything, and yes you can do this “sistering “ a beam is not a big deal but get the correct structural screws the engineer should have specified this , the crack is petty much done but adding a sister won’t hurt and will help but go beyond the crack on either side don’t skimp on the 2x10 .
    – Ed Beal
    Feb 23 at 5:12
  • The same way I told you to do it the last time. It's still "able to carry the load" - "reduce additional cracking" and it will be "structurally sound" "once this is done". It doesn't need any additional lumber. - People were all like, oh but it could crack putting all those screws in. That's what the engineer said to do: put screws in it. And use more lumber so my ass ain't on the line because this is my one job. "recommended" - because they had to tell you to do something that sounded like it was worth $500 to tell you to do.
    – Mazura
    Feb 23 at 22:42
  • diy.stackexchange.com/a/244371/23295 (excellent follow up, +1)
    – Mazura
    Feb 23 at 22:49

1 Answer 1


According to the red line sketch he has on the picture, He just wants you to cut a short piece of 2X10, perhaps 14 1/2" long, screwed with 4 screws each end, my guess would be 3 or 4" screws. I would add a few lines of construction adhesive between the added piece to boot.

With an impact driver to run the screws in, and a drill with a pilot bit for the patch piece, this should be a fairly easy task you can do.

  • 1
    I agree it is simple and + for pilot holes.
    – Ed Beal
    Feb 23 at 5:13
  • 1
    From what the engineer writes, it seems he is saying that as-is the remaining 2 uncracked plies are structurally sufficient. The short sister section would just be to stabilize things and make sure further cracking did not occur.
    – Armand
    Feb 23 at 6:10
  • 2
    That's what i was thinking. I was also figuring just a piece of 3/4" plywood would do the same if not better IMHO, since the crossbanding in the plywood resists cracking better that a short block of 2X10. For me, gluing it is a big help....
    – Jack
    Feb 23 at 6:19
  • Or step up to 1-1/2" plywood, perhaps.
    – Ecnerwal
    Feb 23 at 15:10
  • 1
    If the SE recommended dimensional lumber, I'd stick with that. If he offered plywood as an option, then it's an option. Not sticking with his written recommendation could come back to bite the homeowner should something go wrong in the future.
    – FreeMan
    Feb 24 at 13:52

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.