Do I need a structural engineer for a sagging floor beam?
Paying for a structural engineer feels risky when you are afraid of wasting money if a contractor's reinforcement recommendation is already sufficient for a visibly sagging, deteriorated beam. Additionally, major structural fixes like adding a steel L-shaped beam require a complete rebuild, which stalls out when an HOA refuses to approve the engineering work.
What the numbers show
Counted from the threads quoted below. How we count
- It goes quiet, then comes back — 4 separate clusters since December 2025.
- It is not one crowd: 9 people on Reddit and 2 on Stack Exchange ran into the same thing.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Hiring a structural engineer for a professional evaluationDid this help you?
- 2Installing temporary support postsDid this help you?
- 3Building a plywood box beam reinforcement based on contractor adviceDid this help you?
- 4adding an aluminum edge trimDid this help you?
- 5staining the deck and exposed portions of the beamDid this help you?
- 6Calling foundation companiesDid this help you?
- 7Having the middle of the house jacked upDid this help you?
- 8Asking for recommendations on community forums for structural engineers or general contractors.Did this help you?
- 9Gluing the removed wood pucks back into the holes with construction adhesive.Did this help you?
- 10Installing commercial metal joist reinforcement brackets.Did this help you?
- 11Stopping use of the shower immediatelyDid this help you?
- 12Ripping up the tile to inspect and replace the shower pan and waterproof membraneDid this help you?
- 13Calling the installation company back to fix the connectionDid this help you?
- 14Living with the floor until it fails and expecting a full replacementDid this help you?
- 15Pulling the affected area and pouring self-leveling compoundDid this help you?
- 16Laying plywood over the strips before installing flooringDid this help you?
- 17Getting a structural engineerDid this help you?
- 18Sistering up the joists that don't have full bearingDid this help you?
- 19Sistering a similar-sized board onto the damaged joist extending past the damage and securing with boltsDid this help you?
- 20Cutting through the exterior rim joist to thread a new full-length joist into placeDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“The seals between the tiles are breaking and the surface is lifting up. Why might this be happening and how would we fix it?”source ↗
“In one of the rooms we’ve started noticed some sinking. We don’t know how long it’s been sinking but it’s a big enough gap where it’s caught our attention.”source ↗
“Does anyone have any suggestions for a structure engineer? Or general contractors?”source ↗
“I'm in the process of trying to get a report from an engineer, but I'm also afraid of spending a lot to find out the contractor's recommendation is a fine reinforcement.”source ↗
“All beams had quite visible sag even 10 years ago!”source ↗
“I'm observing a lot of delamination along a particular line (@ ~1/3 height), also overall condition is pretty deteriorated (e.g. check the chipping on the underside).”source ↗
“I would add a steel L -shaped beam under the composite one; problem is - it's a major rebuild, and our HOA doesn't want to hear this (I raised a question of hiring a structural engineer several times).”source ↗
“In my crawlspace, a company installed this post thing. I noticed my floors started shaking more and this is what I found in my crawlspace. How do I fix this?”source ↗
“I went to the basement to see what was going on and found the one floor joist under the length of the island was cut completely through 8 times by previous homeowner for who knows why.”source ↗
“Definitely not the way I wanted to go into the weekend.”source ↗
“I had some electrical work done and the contractor drilled 2 holes not up to code through my floor joists.”source ↗
“I had a structural engineer come out to my house today and he basically said to just glue the wood pucks back into the holes with a little notch for the wire. This seems... wrong.”source ↗
“And would this bracket need to be for oversized holes or is this essentially a notch because of how close it is to the top?”source ↗
“What kind of company would I contact to actually figure out what’s going on with my floors?”source ↗
“I’m physically unable to get into the crawl space myself to really inspect everything and don't even know what to look for”source ↗
“Aunties house has a jumpy floor and I found out why. Any suggestions on how to proceed?”source ↗
“Insanely shitty construction. I’d be more worried that the floor system is exposed to weather. Sister up the joists that don’t have full bearing for now.”source ↗
“A contractor lifted a section of our hardwood during work and this is what was underneath.”source ↗
Where this came up
People with this problem also raised
- 4Should I add plywood to a flexing subfloor or replace it?
- 2Who to call when a wood floor starts buckling after a flood?
- 10How to fix a flexing wood floor without replacing it
- 4Why is the plywood roof decking sagging on my new house?
- 2Can you fix a settling foundation yourself on a tight budget?
- 2Can you cut through a floor joist to run plumbing?