Comments by some very NWFA certified installers regarding OSB and links to information regarding osb and links to more information regarding this issue.

Virginia Tech has documents that show the holding power of fasteners is greatly reduced if the mc of the subfloor is high at the time of installation. Reinstalling a floor on OSB that has been dried to the normal seasonal mc range can work however i am not sure it is worth the risk. If you must install on OSB pay very close attention to your nailing schedule and the subfloor span and spacing of the joists because vertical deflection can and will be the straw that breaks the camels back.

it has always been my understanding that the main issue with staple in OSB is that the 2 points of the staples exert a lot more blunt force over the width of the staple. This tends to punch out potentially larger pieces of the OSB on the back of the subfloor. This may not be the case anymore but I know this used to be the case with OSB.....when this happens ( knocking out chunks from the back of the subfloor using staples) there is less holding power on that particular staple......of course this doesn't matter if the OSB is simply a top layer over existing plywood. With a cleat there is less chance of this "knockout" happening since there is only one point pushing through.......


http://osbguide.tecotested.com/pdfs/en/el812.pdf
http://www.rci-online.org/interface/200 ... murphy.pdf
http://www.mastercodeprofessional.com/m ... lywood.pdf

Thought I posted this before. A nice long thread hardwood installers opinions on OSB.

http://hardwoodfloorsmag.com/forum/topi ... g-osb.aspx

In the UK the main flooring left by the builder is chipboard. Not as good as plywood but still grips the nail. OSB is only for the garden shed roof.

I doubt what the spec would be for adding multiple layers or just a single one but it is pretty obvious that someone screwed up here with using the parallel one for the joist. You should consult first with the real specs.

Then check it with your builder so that you could check whether the claim would be right and so he would not have a good argument should he falter with what he chooses to present. You are at the losing end here so they are going to make it hard for you.

UPDATE:

Over six months ago, I brought in a lawyer in order to get the builder to act. We came to an agreement. The builder would pay to have a home humidifier installed in the central heating and cooling system, so that the house could be kept at a 45% humidity all year round. Once installed, the agreement was that if after 6 months, the floor was still creaking, cracking, and popping, then the builder would replace the floor.

Well, it has been 6 months now, and my house has remained at a minimum of a 45% humidity the entire time. The floor is no better than before. The question I have for the experts here is, what is the best way to replace an improperly installed hardwood floor? Should the hardwood floor planks be replaced with new wood? What about the OSB subfloor? Should the OSB subfloor be replaced, or should a new layer of OSB be added on top of the existing subfloor?

First, I want to add to the original poster. If your using a fastener that is longer than the thickness of the wood and OSB that is going to blow through the bottom of the OSB, then why not use a shorter fastener?

@ Luke, just my opinion but I think is documented in research. When OSB has been damaged by water it is not going to fix itself when dried back down or by adding moisture via humidification. When it is damaged and will not sufficiently hold a fastener it is history. So, why would you want to fasten more OSB to damaged OSB? What would be the point?

So it is best for the sub-floor to be replaced?

This is a true statement. They paid for it and they own it, to do as they wish with the report.

At this point it is up to you to get your own independent investigation done.

I would replace the sub floor,since I will be doing the same thing to my whole house(and making sure it's level too.).

I have come across the exact same flooring problem, crackling, popping sound. More than an coincident, it is a Metropolitan floor. What was the flooring you had installed? Our's, Engineered Jatoba Kentwood. We noticed a problem as soon as it was laid. It has gotten worse and worse. We had a flooring expert do an inspection and came to the conclusion the flooring was crowning up and the subfloor was cupped downward. The staples are not long enough to secure the flooring to the subfloor. Amazingly, soon after our our problem was brought to light and they visited our house, Metropolitan has changed their staple length specification to a longer staple. The Metropolitan's report was written by the same gentleman as yours since we live in Sammamish.
We are in a rather contentious law suit over the floor with the contractor and flooring subcontractor with their expert witnesses' saying industry standards do not say floors should be noise free. Noise levels are subjective so they believe there is no problem with the floor. The contractor we have hired as our expert witness is certain when one board on the floor is removed the rest will pop right out with no effort.
I would certainly like more information about your flooring issues and talk with you.

Results I have seen inspecting this condition. Subfloor not correct width for the spacing by builder. Also many were not Exposure 1 which is a requirement by all mfg's. Nailing schedule should be 6" on perimeter 12" in center. Exotics most mfg's generally require 18 gage cleats, not staples as staples tend to act as a small chisel and fracture the tongues resulting in movement. One new home, destructive testing i.e. removal of boards in trouble areas to inspect length and type of fasteners, 80% fractured. Hardwood within 1" to 3" of each end wide boards require 6" to 8" minimum one mfg required 4" to 6" min..
Sometimes in arid areas if RH not met wood shrinks and much noise and movement possible. Movement and noise always requires removal to determine cause or your wasting money on that inspection. ONLY testing can provide the conclusive answer you will need to find cause and party responsible. Additionally get a copy of the mfg's installation procedures and warranty info. Generally, you can download from the mfg website.
10 board measurements should be taken with each individual board measured with a digital micrometer. Moisture contents top and bottom with slide hammer moisture meter and insulated pins. Ambient relative humidity readings. Take mc readings of subfloor only then can one even begin to understand what is causing your concern. Looking at a floor one can sometimes correctly identify the problem but then testing will prove it conclusively. Think of it this way a policeman knows you are guilty but only when he can prove it will you get a conviction. Most of my inspections of any consequence require 3-4 hours on site and double that to write a conclusive report backed up by Industry Standards.

We did hire an inspector who with he contractor removed some flooring. He concluded the sub floor was not flat with low spots and the flooring is bowed. The staples are not long enough to hold the flooring to the sub floor.
Metropolitan's "expert" also visited the house twice and in his report stated "the failure of the floor to function as expected", "the creaking etc. of the floor is caused by movement" and "the flooring should not move." Again, our contractor says, whether noise is a problem is arbitrary and is fighting us.
If anyone else has had a similar problem with a KENTWOOD floor. I would like to contact you.

Since the original intent was to have the flooring running in the direction it is. They failed to do the proper procedure, to do it right.

I would not replace the subfloor. I would overlay it with plywood, like it was suppose to have been done in the first place.

Luke,
For some reason I can not send you an off-line message. Would you please contact me again.
Sammamish (same floor problem)

I didn't see anyone post about the Subfloor.

It was mentioned a new construction which leads me to believe there may be some sheared nails rubbing on the joists OR /AND the builder didn't use glue for the initial subfloor?

If the hardware floor was installed during construction, then no one would have known if the issue existing before, maybe only the person laying the floor at the time.

I would check for sheared nails from the basement, if the ceiling below is finished, as much as you been through you may want to remove some sheet rock and inspect it.

Also typically hardwood floors are making cracking noises unless the install was a very very poor install. I know there are some out there but....

A cracking or squeaking noise comes from two pieces of wood rubbing together, or a sheared nail on the joists.

So either the wood floor tung and groove has shrunken and the installer didn't nail it good enough, or the butt joints are not tung and groove and they are rubbing together.

If its a big problem since 2005, just rip out the old floor and re-do it. I know it might be costly but it sounds like you tried to get it warranted with no success.

Sorry to hear that.