A while back I mentioned that we had a piece of floor that seemed to have termite damage in the subfloor that was causing flex in a certain piece of our hardwood (Repairing a subfloor without demolition). We got a lot of very good suggestions from the blogging community.. unfortunately it turns out we were wrong in our diagnosis of the problem.
In the picture to the left you can see the two pieces of hardwood that “flexed” oddly. On Thursday of their vacation Dad and Marc crawled under the house to check out the supposed “termite damage” that was our suspected culprit for the flex. They poked and prodded with an awl for quite a while but they didn’t find any punky wood. Everything in the subfloor looks really good. Still the hardwood flexed. After mulling it over for a couple of days, Dad decided how we would tackle this problem. On Saturday he carefully remove those pieces of hardwood from above to see if he could identify the problem.
First Dad scored a line across the boards with his utility knife. Then he used a hammer to run the utility knife deeper and deeper along that score line until he cut through the hardwood boards on both ends. We removed these boards and found the subfloor to be in perfect condition. Our culprit was actually the hardwood itself.
If you look closely at this picture you can see how the ends of the board are about twice as thick as the middle of the board.
We found that the boards we removed were a lot thinner in the middle than on the ends. My personal theory is that the house has shifted over time.. and in this spot the hardwood was pinched and flexed a little bit upwards. That was okay up until the point where we sanded the hell out of the hardwood floor. Once we removed enough material from that board the “flex” in the board when you stepped on it became really apparant.
Dad’s solution was to slightly trim one end of the pieces we removed so that they no longer flexed. Then he filled the void with adhesive and applied weights to the top to hold the boards level.
Ta-Da, no more flex.