Hardwood Floors Cupping - Help Needed

14 years ago

Our house is 1 1/2 years old. We have white oak floors throughout the house. This year right around the holidays, we noticed the cupping and it got worse and has stabilized. The humidity in the house is about 40% and the humidity under the house is also within acceptable range. The builder had his floor guy test the wood and it also was within the acceptable range. We have hd no leaks or water damage to the floors.

My husband said that when the wood was first installed and finished, he noticed that the seams between the boards were not perfectly flat but he thought that was normal.

Anyone familiar with this problem? Our builder is stumped. We are anxious to get this resolved because anything I have read says that the longer the floors are cupped the less likely they will return to normal.

Sort by:Oldest

Comments (7)

glennsfc
14 years ago
What do you mean by "humidity under the house?"
kathy50
Original Author
14 years ago
It seems that the house humidity is fine so the problem must be under the house. We have no basement but do have a 10x20 ft. crawl space. We have poly on the ground to help keep moisture down and no visible puddles or leaks. Someone suggested fans, a dehumidifier in the crawl space. I guess the next step should be to call in an inspector. We cannot locate the cause of the moisture which is causing the cupping. The builder assured us it is not a problem with the wood or the installation.
Related Discussions
HELP!!! Hardwood Floors Cupping
Q
Comments (12)
@nikki1307 - I'm sorry to say but you needed to have the vapour barrier in the crawlspace BEFORE the floor was installed. Sorry but this is not the fault of the flooring installers. A General Contractor (who is INSTRUCTED to investigate the crawlspace and correct it prior to flooring being installed) could have caught this. Now that this has happened, you will need to get the vapour barrier over the earth in the crawlspace QUICKLY. The garage space is another problem. Garage "slabs" (concrete normally) rarely have vapour barriers installed under them. Therefore the concrete in the garage will be allowing water vapour through at a rate that is ALMOST as bad as the crawlspace. When applying vapour barriers to a CEILING in a garage, you will need some help. The one thing we try to avoid is a "double" vapour barrier. That's a bad situation. You will want to contract a moisture remediation company (when you deal with the crawlspace) to help with the garage ceiling. As for what the wood will do "after" the moisture has been dealt with, it will take TIME. Lots and lots of time. You will apply the vapour barriers (possibly a dehumidifier in the garage to help you if you can't get a vapour barrier on the ceiling....wood does NOT like plastic sitting next to it) and then wait. The wood will correct a LITTLE bit...maybe 25% - 50% better. It takes a LONG TIME for wood to LOOSE moisture. Almost TWICE as long as it takes it to GAIN moisture. So if this has been going on for 4 years....you can almost certainly double that time to lose it. I would give it a few years (like 2) and then look to see how much the wood has corrected. You don't want to do ANYTHING to it until you are CERTAIN that the change in appearance is "finished" changing. Once you have waited another 2 years (or so...it isn't set in stone) you can then go ahead and have it sanded and refinished. Once it has STABILIZED (this is SUPER important) then the chances of it changing and cupping again are VERY slim.... Until another moisture issue pops up. Then all bets are off - of course.
...See More
red oak hardwood cupping-- need help asap!!
Q
Comments (3)
Was anything installed between the subfloor and the flooring? The ambient hot weather/humid conditions obviously affected your flooring. You got two different prescriptions because there are many ways to cure imbalances in moisture levels above and below flooring. Sealing and dehumidifying the crawlspace is just one approach. I have even seen situations in which existing flooring was just fine until a basement area was insulated and then finished. In those instances, the flooring crowned and gaps appeared between the boards.
...See More
Hardwood Floors installed 6 months ago are still cupped and squeak
Q
Comments (18)
If, your flooring is cupped. You need to get your basement RH level down. It needs to be lower than the level above. Usually between 30-35% RH. Otherwise, your subfloor will not dry out. If, the above level is around 35% or lower. Try increasing it to 40%. As jfcwood mentioned, the bottom of your floor boards has a higher moisture content causing the base of the floor boards to expand. In order to shrink it, the RH level needs to be lower along the base of the floor boards. Cool, wet air is a wet basement. Check sump pump wells, it can be holding water. Are you running a dehumidifier? Are you by the water? Is the cupping consistent throughout the home or is it isolated to a particular area? Are you using a diluted cleaner? Also, did the NWFA inspector take a wood moisture reading with a lignometer? The reading should be consistent throughout, cupped or not. Are you able to take a reading of the subfloor from underneath? If, finished is there a vent you can take a reading from? The reading should be within 3% of the sub-floor to be considered stable. If, it is then someone needs to be responsible for a tear out and redo. Who or what caused the moisture issue?
...See More
Will the cupping hardwood floors on our new construction lie down?
Q
Comments (48)
If it is cupping, it looks pretty slight to me. Cupping--unless it's evident shortly after installation--is usually the result of moisture imbalances which are due to environmental conditions outside the contractor's control. Cupping is more evident the wider the flooring width which is why I recommend engineered hardwood for widths greater than 3" As a point of calibration, the performance standard published in NAHB's Residential Construction Performance Guidelines for Professional Builders and Remodelers is: "Cupping or crowning in hardwood floor boards will not exceed 1 /16 inch in height in a 3-inch maximum span measured perpendicular to the long axis of the board. Cupping or crowning appearing after installation may result from fluctuations in the moisture conditions in the house, causing a noticeable curvature in the face of the floor boards. Cupping or crowning caused by exposure to moisture beyond the contractor’s control is not the contractor’s responsibility." If the OP wants to minimize cupping, they'll need to control the relative humidity in the living space as well as the space below the floor. If it's a basement or crawl space, moisture controls need to be in place and some amount of conditioning may be required.
...See More
woodfloorpro
14 years ago
The only cause of cupping is moisture from below. Someone is missing something.
glennsfc
14 years ago
What did the installer place between the plywood subfloor and the wood flooring? Anything?

There are several ways to handle moisture in crawl spaces. The poly is fine, however it does nothing to prevent moisture from coming into a crawl space through the vents and condensing under certain temperature conditions. Is your crawl space vented?

Relatively new protocol is to seal the crawl space and provide dehumidification. The rationale here is that if the occupied space is climate controlled, then the underfloor space needs to be controlled as well to prevent unbalanced relative humidity levels between the two spaces. If you have a drier environment above the floor than under it, you will see the cupping you experience from time to time with this floor.

Two simple temperature and humidity indicators will be able to tell you the temperature and humidity level differences between the two spaces. You can purchase these for about $20 each at any Radio Shack store. Then, you do a little research on the subject "relative humidity"...and that may help you understand what it going on with your floor.

We will be curious to learn what your flooring inspector may tell you, should you go that route.
kathy50
Original Author
14 years ago
Thanks for your help. We will get another temperature/humidity indicator for the crawl space. We just put one in the living room and we are consistenly measuring 37% humidity. Our builder just lowered the humidifier to #1 (out of 7). I guess we are making things worse by lowering the house humidity but as I said he insists the house is too humid which he says is the problem. I will keep everyone posted because this is very frustrating for us.
brickeyee
14 years ago
Higher humidity is usually the cause of cupping, not lower.

Part of the problem is that it can take weeks for the moisture content of the floor to adjust after a humidity change is made.
woodfloorpro
14 years ago
The house is not too humid it should be 35-55% range year round.

Hardwood Floors Cupping - Help Needed

Comments (7)

glennsfc

kathy50
Original Author

Related Discussions

woodfloorpro

glennsfc

kathy50
Original Author

brickeyee

woodfloorpro

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Hardwood Floors Cupping - Help Needed

Comments (7)

glennsfc

kathy50Original Author

Related Discussions

woodfloorpro

glennsfc

kathy50Original Author

brickeyee

woodfloorpro

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

kathy50
Original Author

kathy50
Original Author