Lighter color in seams of hardwood

Q: This past summer we purchased a 50-60 yr. old home, ripped up the old brdlm. to expose the hardwood floors. We also had to add hardwood floors to a room that had a addition added. We wanted to stain a dark chocolate brown, so we hired a company to sand/refinish. When they initially looked at the floor, they said floor is nice and thick/never been sanded. Our 1st problem was the installers did not let the 2 top coats (sealer/etc.) dry completely because it was very humid and they told us it was okay to move in.

We have buff marks all over various parts of the house from the buffer sticking. (We were compensated for this problem.)

In December we noticed between the seams of the hardwood floor you can see gaps/lighter color. Even on the new hardwood that they installed. The company came back again and said it was expansion/contraction and low humidity in the house and because the hardwood was covered with brdlm for years (At one time the hardwood was exposed.) No one told us at the start that the floors could do this, we have never heard of this, and if this was told to us we might have gone with a lighter color. Would love your opinion on this matter.

A: Polisher swirls are generally a problem when finishing with a gloss finish. It is a tough problem because previous coats may need to be abraded to gain adhesion, depending on the finish used. They don’t usually show up in low sheen finishes. Did you have water borne or oil modified applied? I ask this because water borne don’t stretch as well as oil, and if the floor shrinks the water borne will fracture and can leave what looks like white lines along board edges.

Related Q: We had our floors refinished (sanded and restained) last summer. Since then, in the late fall, we began to notice lines forming at the seams between the boards and then in some places the finish is coming off.

A: I can only guess they used a water borne finish which tends to be less able to stretch. Heating season arrives, the humidity levels drop and wood floors may shrink slightly stretching the finish that has bridged from one board to the next. Now it fractures and may flake slightly at those fracture points. There are sealers designed to use with these finishes which can help prevent situations like this.

I would call the company who did the work and have them come and have a look and perhaps coat it again.