Hairline cracks

Q: I just installed engineered Brazilian cherry throughout my 11-yr old house (5-1/4″ wide, 3/8″ thick). We are going thru our first Texan winter (close to freezing) and the floor is popping like chestnuts in an open fire. I got down on my knees and found hairline cracks developing on my floors.

Did I just lose my floors?

A: Hairline cracks where? On top of the boards? Or do you mean gaps are developing between the boards? Is this site finished or pre finished? Probably the floors are shrinking because the furnace is on, so you might need to add a bit of humidity to the air. The purchase of a hygrometer can also tell you what the relative humidity is in the room, and even at floor level if it is placed on the floor surface for half an hour or so. If the furnace is running, try to keep it from 35 to 40% if possible. Being down on the coast or near the coast, if this was installed in summer when humidity is high, you need to try to keep the RH at least in the ball park of the installation environment.

Similar Q: I recently noticed small hairline cracks on a couple floor boards right at the ends. They are about and inch or two long with the grain near the center of the board. The affected boards are in the same general area of the room and it is high traffic. The floor is 5 years old. I suspect it may be humidity related as it’s now spring. Is it something I need to concern myself with?

A: No need to worry about it until or unless it gets much worse, in which case the boards could be replaced.