Our builder is just finishing installation of 2000 SF of pre-finished solid wood T+G floors in our new house. The flooring was installed over rosin paper, over floor sheathing that meets or exceeds the building code required thickness. The floors squeek. Lots. The squeeks vary from about 4 squeeks per 100 SF in the rooms with little direct sun to one at every footstep in the rooms with lots of sun. The sub-floors were scrutinized and checked for squeeks by the lead carpenter just before flooring installation. He lifted and re-glued, and re-screwed the sub-floor as was necessary. The flooring wood was acclimated to the room temperature/humidity in the rooms that have the least squeeks, but not in the rooms that have the most.

What causes this? How do we find out what is an acceptable practice? Is there an industry standard specification we can refer to? Are there experts who can advise? How is a problem like this fixed?

There is no rule for squeaks. If milled correctly and installed over a proper subfloor it shouldn't squeak much. The wider the board the more squeaks are likely due to the fact the floor has less fasteners than a narrow width. Also, the specie of wood can come into play. Hickory will move enough overnight to squeak and pop even when its put down correctly. squeaks come from some deflection something has to be moving to create the squeak, stop the movement youll stop the squeaks. To give you a better idea we need more info. MC of flooring and subfloor, subfloor type, fastner size and lenghth, nail spacing, joist spacing. Did they install the floor perpendicular to the floor joist? Type and size of wood floor.

are you sure it is squeaking and not cracking and popping from fresh tight installation..this happens as the floor finds it comfort zone.

if the subfloor is screwed and glued and its squeaking then it may be the joists or joist hangers..

if its T&G plywood or OSB this can be the source as well.

if the nose come from the wood floor itself, its in the T7G milling..its probably too loose.

Clearly establish the type of noise and which floor it is coming from.

Thanks for your comments. The wood is pre-finished red birch, select grade.

We don't know the details of how the floor was attached (nail spacing, etc) other than it is on rosin paper. We have one room with a buckle in the middle of the flooring; it is easy to see that the flooring has lifted.

We do have squeaks and popping. One person described it as like "walking on potato chip flooring."

We have measured the moisture in the flooring and the relative humidity several of the rooms. Here is the record:
Sun Room (a fully conditioned space but with lots of glass walls) RH 51%, wood flooring moisture 0%
Master Bedroom, temperature 68 degrees, RH 51%, wood flooring 1%
Master Dressing Room wood flooring 2.25%

Any more thoughts?
Thanks
Second Bedroom wood flooring .5%
Study Room wood flooring 5.5%
Kitchen wood flooring 6.5%

Thsnk ypu for your thoughts on this.

those readings are all over the place..they may no be accurate. Who took them?

I would advise you to hire an independent NWFA wood flooring inspector.

I don't know what state you are located in..there is one right here on the board that posts occasionally named Jim Decker.

Just make sure you Hire NWFA inspector.

they will perform the necessary tests and readings and tell you where the install failed.You can then use the findings to negotoiate the proper correction with the installers/builder.

Earth magnets will determine the nailing schedule. I have found many not nailed within 3" of each end and instead of 6' to 8" anywhere from 12" to as much as 18" which will provide movement thus squeaking. Fracturing tongues
by not using the correct fastener will also produce movement. Staples favored by many installers if the air pressure is not set correctly can be like a chisel fracturing the tongues. Sometimes I find all kinds. Only removing an area and checking these things will one get a definitive answer. Did they use plywood or osb? Was it nailed correctly to the joists? Take no ones word for it pull some and find out.
Get the mfg installation instructions and see what they call for even the NWFA states mfg requirements more stringent than NWFA must be followed.
Floor joists widths require different layers of plywood or osb.
Low humidity can cause wood to shrink causing squeaks. Find out the width of the boards when mfg and using a digital micrometer will most definitively prove this. The moisture readings stated would have been caused by relative humidity readings of 8% to 10% for a prolonged period.
The best way to determine cause is hire an NWFA inspector in your area. He has the tools and training to accurately determine cause. Go to http://www.nwfa.org/cp-inspector.aspx and find one in your area. A thorough inspection will determine why you are experiencing your concern. I would really like to hear his answer.