Building Homes or Extensions/2nd & 1st floor dip and sag


QUESTION: The back half of my 25-year old townhouse condo (end unit) is sagging in the middle.
Additionally,  the place has always had the creakiest and loudest floors ever heard although they are carpeted.  They creak even when the cat walks on them.

I have had various contractors in over the years and all but one stated that after looking up at the ceiling in the basement that there is no problem.  The beams down there are fine and even etc...

One contractor told me that the edges on some of the on the floor do not actually land on the wood beam and he could fix it when it came time to replace the rug.

A contractor in my complex, not available to help/work for me told me that when he replaced his carpeting he had to replace all the floor plywood(?) because they were of different sizes and heights, but, again, my situation seems beyond that.  The sagging goes to the center of the building.

Thank you for anything you may offer in education

I paid for a licensed and experienced home inspector about 10-years ago, but he couldn't find anything.  

But the sagging and dipping are getting worse even recognizing floors change seasonally a bit.

Do I need a structural engineer? I don't know anyone that can recommend one.  How do I find a reputable one?  What is their procedure?  Do they come out and look around and give a report or ?  How much do they cost?   I have a total of about 1,000 square feet between my first and second floor.

ANSWER: Hi Joanne, a problem like this needs to have some selective demolition work to the ceiling below the problem area to see what's going on with the structure.  Or as the one contractor mentioned, pull up the carpet, pull up some of the plywood and do the inspection from the top down.  It's possible that the floor system was improperly framed and then covered up.  The joists might be undersized, there might have been some plumbing pipes that needed routing and someone cut too much out of some of the joists and they are failing, improperly fastened joist hangers, undersized support beams..

By cutting a hole in the drywall ceiling below and shining a light up inside you might be able to get an idea as to what is going on.  The drywall can always be patched afterwards.  Also you don't need to wait until your carpet needs replacing.  A carpet layer can always restretch your existing carpet after a contractor pulls it up to fix the problem.

One last note, many condominium documents give the homeowner certain rights and the structure may be covered by your association dues.

As far as costs go, I can't imagine it costing more than a thousand dollars, worst case scenario.  Try to get a ballpark figure from a reputable contractor and hold them to it.  This would be a two part agreement.  The first agreement would be a price to open up the floor or ceiling and analyze the problem.  This should only cost a couple hundred dollars.  Cheaper to cut the drywall and patch but by pulling up the carpet and taking up a piece of plywood half the work is already done so the actual repair would be cheaper.
I hope this info helps, feel free to write again regarding this or other matters, sincerely, Bruce Johnson,

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QUESTION: Bruce, what a mighty fast reply and seems like you've given a terrific and detailed answer. I'm not always the swiftest; is my comprehension on a couple things below correct?
1. Don't start off with a structural engineer, get a contractor.
2. If correct then  I live in an area where it seems contractors and GCs claim to do anything and everything. Other than electricians, plumbers, and a few handymen and carpenters the results are not always good in this area.   With that and this seeming to be an odd situation, would I be best off looking for a specific type of contractor or someone with certain experience?
3. A couple hundred dollars to check it out-got it, but  was the thousand dollars to correct the situation?

Thank you again, good sir.

Hi again Joanne, I wouldn't involve a structural engineer unless something out of the ordinary is discovered that needs to be re engineered.  That would probably be like a sinkhole or some other foundation problem.  But nothing was mentioned about the basement slab sinking  in this general area.  A GC or framing contractor could probably discover the problem and fix it right away whereas you would need a contractor to open up the floor for the engineer anyway and chances are he can take care of the problem then and there.   That's why I put a thousand dollar figure on it, it's really only a days job if approached properly..but it can get complicated real fast with an engineer involved thus driving the price up..there can't be too many reasons..a shim used to level up a floor joist may have slipped out, something might not have been nailed properly, or heaven forbid, termites.  If it is termites then all the bad wood will have to be replaced and then the area treated, so that would run more. All I can do is speculate at this point..sincerely Bruce  

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Bruce E. Johnson


I can answer any construction related question in regards to carpentry, concrete, drywall, masonry, structural elements of any type of building, residential or commercial. Interior or exterior.


Custom Commercial and residential buildings. Churches, theaters, schools and auditoriums. Most recently I am working with the Catholic Church on several design build committees. I have a website related to scheduling and project supervision. Although my expertise is more related to multimillion dollar commercial, educational and theatrical projects my generous credentials in residential and remodelling construction make me a viable source of information regarding all forms of building questions.

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