The Flooring Expert

Q: Katrina Renovations Deep in the South:

Thanks,
Bob

A: The major problem here is moisture content. According to the National Oak Flooring Manufacturer's Association (more commonly called NOFMA) the optimal moisture content range for solid oak flooring is between 6-8%. Now this can go upwards of 10%, but generally you want the floor to be within 1-2% of your subfloor's moisture content. Mold and mildew begin to form at roughly 18% moisture content.

As far as relative humidity goes you want to have it between 30 and 40%. This means that the amount of moisture in the air of your home is also a bit high for a solid hardwood floor. The big problem here is the amount of moisture in your subfloor, which is then getting into your flooring along with relative humidity of your home.

What you will need to do is get some dehumidifiers running in your home to pull all of this additional moisture from the flooring and air. Depending on how long your floor has shown the cupping, if the moisture is pulled out it could revert back to normal. At the very least the cupping will lessen quite a bit as the flooring returns to its manufactured norm of 6-8%.

Q: I am in the process of installing hardwood floor (Kahrs Brazilian Cherry) in our home, and some of the boards are significantly warped out of the box. I called Kahrs technical support line here in the US and asked what is considered tolerable when it comes to the straightness of hardwood floor boards, but he didnʼt want to give me any detailed information. I mentioned that one of the boards is so significantly warped that I can put my hand underneath it, and I measured the distance from the middle to the ground to be approximately 1 inch. When asked if this number would be acceptable, the customer representative mentioned that it is, which of course left me puzzled as I consider 1 inch unacceptable.

Thanks so much for your help,
Gilbert

A: Typically when boards are bowed as much as the ones you have received, replacements are in order from the retailer who sold them. Typically this comes with a claims process of some form. This being said, boards in similar conditions have been installed in the past successfully and there are some ways to relieve this kind of bowing.

Any established numbers would have to come directly from the manufacturer of the product, as it is their duty to determine what is and is not within tolerances. If a member of that company who has proper authorization says it is within tolerance, then I would get some documentation just to ensure your warranty remains intact.

One method suggested by Gene D., iFLOOR's commercial contract manager, for repairing a bow like this involves a simple hand-held clothing steam-iron and a towel. Wrap the towel around the iron, then dial up the steam and begin ironing out the board from the center, working outward. The heat will help to relieve the board's bowing. This is much like the process used to form wood for ships or furniture, a careful application of heat and steam will help to form the board.

Now if this process is a bit too slow for your liking, then install the board and glue, but once the board is in place, before the adhesive cures, use a sand bag to weight down the board so that the adhesive cures with the board in a flat position, locking it in. You can make your own sand bags if you want smaller bags that are a bit more form fitting for the board.

Personally I would first contact the retailer you purchased the flooring from and request replacements. If the retailer can confirm these boards are within tolerance, and provide documentation, then either install them and bag the boards down or do the repair method using an iron before installing.

Q: Help! About 7 years ago my wife and I installed Columbia Click flooring in our Condo. IT has been great - up until about two weeks ago. In our dining area, which is about 100sq ft in size, right about in the middle it started to buckle and warp upwards.

There are no water pipes or anything of that nature in the dining area, and we haven't spilled anything on it. Only two things in the house have changed but I can't imagine this is it:

1. We had air conditioning installed last year and also started using forced air heat to warm our condo in the winter (we live in San Diego and frankly never used the heater until we upgraded to whole HVAC system). We have one output vent in the dinign area, but not near where it is buckling. We haven't even really used the A/C this year. Could the heat/ac combination have caused this? The floor now expands and contracts more often than it did before????

2. We have a three year old daughter. Last year we bought her a small play kitchen. It is the only other thing in the dining room besides the dining room table. It weighs about 45 pounds. It is up against one of the walls. Could it be causing the floor to not float as freely?

Finally - how do we stop it and/or repair it without redoing the entire dining area? The warp is now about 1/4' inch high. Enough to notice while walking thru and even catching a foot on when walking by.

We do have some planks left over from the initial install, but I would even want to try cutting out and repairing the warped area without understanding the cause first.

I did some follow up to get a bit more information on the room and a few pictures:

Follow-up: Did the best I could on pics and I hope this gives you a good idea. Attached are 3 pics:

Regarding the other 3 sides of the room and expansion gaps, I can tell you this. The side I am standing on when taking the pic is where my daughters play kitchen is. I pulled off that moulding easily and there is a half inch of expansion space. So that covers 2 of the 4 sides of the room.

Unfortunately the other two sides the moulding a nailed on pretty good and I didn't want to wreck it. But from my memory I was super worried about that aspect when installing and left 1/2' at least everywhere. If after reviewing the info on 2 sides of the room you think I should pull the moulding to be sure of the expansion gaps, let me know.

After looking at this myself, my theory is the HVAC vent routes underneath here and is causing condensation and the subfloor is warping. I just don't know how to proof it. One thing that causes me to go against that theory is that the condensation should drop downwards and not upwards. I would also think that I'd get drips thru the drywall ceiling in the basement and I don't see that. There is also one other room where the vent routes underneath the floor just like in the dining area and there are no problems in that room.

Anyway, open to ideas and how to start in fixing this. I have a horrible feeling of replacing the entire floor in the dining area.

- Steve

A: I had a chat with Gene D., iFLOOR's commercial contract specialist to bounce a few ideas around. Our suggestion would be to first remove those last few base molds to make sure the expansion gap is in place. If the gap is gone, then removing the molding should establish some room and help your floor relax back into place.

If they are still there and the floor has not expanded to remove the entire gap, then you are more than likely looking at some moisture issue. I would suggest picking up a moisture meter from a local home store (should run you around $20-$25) and test the moisture content at the raised area versus an edge of the floor. If there is a difference, there is your culprit, if not, then its most likely an issue in your subfloor.

If this is the case, you could try weighing down that portion of the floor, sand bag or some such. You could also apply a bit of heat to the boards to help remove some moisture, then weigh it down with sand bags and it should relax the boards back down. One method of heating would be to wrap a steam iron with a towel, shoot a bit of hot steam into the towel and iron the boards, but use this as a last resort.