I would suggest you get a structural engineer.

Do you have visual access to the subfloor below? for example, if issue is on the main floor, do you have basement access to see the main level floor?

Also, if your builder did multiple homes on your street, talk to your neighbors and see if they have similar issues.

be prepared if you don't have access to below the floor that you may need to tear up some of the finished floor for inspection.

good luck.

Yes, this is the first floor of a ranch home. I have full access to the subfloor from the basement (save for where HVAC is in the way). This was a semi-custom home built on 2.5 acres of vacant land so the neighbor idea is out. Thanks for the feedback.

this might be hard to do, but can you go downstairs and look at the joists and see if there are either large nails or screws near the joist.

my thinking is maybe they missed the joist when installing the plywood. just an idea. I still think you need to get a structural engineer out there to make a better determination. not to mention an engineers conclusion will hold up better in court, if that's your plan of attack.

Yes I can see many screws that missed joists. Yes, my path is to try and build a documented case with professionals. Thanks for the feedback.

In addition to what already has been said...3/4" hardwood floating off the subfloor usually means too few fasteners per board or a skip fastening method (i.e. nailing every second or third board).

You need a certified building inspector to assess the issues you have with the build. That person would be able to determine what is going on with the subfloor, and grade the overall workmanship level and note any deficiencies.

The builder's claim that the humidity level is too high may be correct. However if it is exceedingly high, then what is the cause? Was the home exposed to rain and not allowed to dry sufficiently when closed in and weatherproofed? Buy a humidity meter and do some of your own measurements.

Good luck.

Thanks for the feedback glennsfc. Do you believe a general building inspector is the right professional to document this?

Also, regarding the fastening frequency, this has been checked by a hardwood floor expert. He concluded that it wasn't "best practice" but should not have caused the issues I am seeing.

As far as humidity, the hardwood floor expert did conclude that the humidity in the home since we started occupying it (December 2013) would not have caused this. That is not to say that the humidity when the floor was laid and during the building process are not the cause. We did check the subfloor humidity and the wood humidity during the inspection. The floor installer says it was tested prior to installing the floor in the house as well. I am running a dehumidifier in the basement at 60% and have been monitoring the upstairs as well.

Since you believe you might have an issue with how the subfloor was installed and because you think it might have something to do with your flooring issues, then someone who specializes in issues having to do with general construction practices would be the person to contact. Know that your clock is probably running out to file any kind of workmanship complaint regarding your new build.

I don't know what title that kind of expert would use.

After thinking about it a bit more, I think Glennsfc is probably more correct than my idea of a structural engineer.

a certified building inspector is probably the route I would take. but that's not to say a structural engineer isn't a bad idea either. its one of the things where you might call both, explain the situation and see if either one of them can say over the phone if its something they can provide insight on.

but Glennsfc is on point with the fact that your time is running thin, and actions need to take place asap.

Had an inspection done. The conclusion is poor workmanship when securing the decking to the floor joists. Lack of glue and lack of fasteners. That is not to say they were not used, just that glue/fasteners were not used sufficiently. He was also questioning the hardwood fastening being done by staples rather then cleats. I am not sure what the "next step" will be. Working with my lawyer to see if any of this is claimable.

that's a shame. glad you had the inspection done.

I've noticed back in 2005-6 when the housing market was huge and right before it crashed, houses were going up left and right and I also wondered if there were skipping corners. I know some of the floors that were being put in were not the "best" but I didn't know better as I was still a newbee.

You'd think with it being a single project that they would rush. but Please keep us updated when you find out more.

@mjwkr2000 did you get any resolution on this issue?. I am probably in a similar boat and want to understand how to go about it as well

Ultimately, no. We went the route of filing a claim with the LARA in the state of Michigan. We had the township building inspector come back, pulled up floor and he confirmed the subfloor was NOT fastened to code. We thought this was the smoking gun, the guy who "approved" the builders work had come back stating it was not to code and should be repaired. Unfortunately the state throughout the case and we have been living with it. Truly it doesn't both me as much anymore, but some days I get really angry about it. The cost and time to correct at this point isn't worth it. Likely, when its time to refinish the floor we will probably go the extra mile of removing all the flooring and addressing the issue. Until then, we will live with it.

@mjwkr2000 Sorry to hear that. We have a similar issue with house that went through episodes of rains during construction but had sufficient time to dry from Aug to Oct before hardwoods went in but since we moved in december we use to feel the bouncy floor and a couple of small squeaks here and there but now its started to get a lot worse with many spots, the 2nd floor carpet also has same issues with squeaks, we did have a few during inspection and was mentioned in the report and the builder did try rectifyin it and now they are back again. For hardwoods we were told the installer would sand and then install and the screws should hold the sub floor but i guess the rain should have made the floors squeaky and the builder did not take the effort to add more screws. We were thinking of getting a NWFA inspector to come evaluate our hardwood floors. What inspectors did you end up going with in the early part of the process?.

For our case we used an NWFA inspector, a regular house inspector and the township inspector. All confirmed the same "root cause" that the subfloor was not properly secured to the floor joists (inadequate fastening). All three of these reports were included in our claim to the board of legal and regulatory affairs. The State dismissed the case based on insufficient evidence. I honestly don't know what else we could have done. To go to small claims court would have cost more than replacing the floor and the likelihood of getting recovery of court/legal fees + floor costs even with a win were too low to bother.

@mjwkr2000: small claims cost very little- should not be more than $50. I had used it a few years back in NY.; yes it depends on the amount of claim.

Replacing will sure cost a few thousand.

It is really unfortunate and unfair that after going through so much of hassles, time and money, the problem could not be resolved even when the code violation was acknowledged. The system must be rigged!

If of any value, this is a case that needs to be reported to the US attorney.- strictly for ethical reasons. What else could amount to enough evidence when the CODE violation is thrown out of the window?

I myself have a similar problem-- a new house only 6 months since moved in. The builder does give a 1-year of fit-n-finish warranty, but getting the problem actually resolved is just another issue. Usually, it is nothing simple enough to fix against the warranty.