I recently bought a house that's 43 years old, and I noticed the I-beam spanning 25 feet has a noticeable sag or 'smile' to it after my HVAC guy pointed it out. I'm really concerned about this issue, as I don't want to compromise the floor's integrity, but I'd also prefer not to block the egress down below. Should I install a support in the middle, or is it safe to just hope for the best?
3 Answers
From what I see, that beam might need a bit more than just a center post. There’s a possibility you could have two posts placed more inward from the current ends, given it seems to be deflecting a lot. It might be a good time to consider reinforcements for the floor too, especially if it’s looking like it could cause issues down the line.
That sag looks pretty serious. You really need to check how deep that beam is; a good rule of thumb is that it should be around 0.6 times the span in inches, so for a 25-foot span, you’d want at least a 15-inch deep beam. It might even be worth contacting a structural engineer to take a look, just to be safe!
Yeah, definitely get a structural engineer involved. There’s a good chance you need a support in the middle of that span. If you haven't noticed any existing supports under it, that's something to look into too. Better safe than sorry with these things!