Three years ago we had a house fire. Our main floor was completely redone, with the exception of our wood floors. We were told they were in relatively good shape and could be saved; they'd be sanded down and refinished. THe roof was removed and left off for two weeks. In that time, the floors were totally exposed to the elements--it poured down rain and the hot summer sun beat on them. When the roof was finally put on, the company hired to do the repairs on our house brought in small dehumidifiers and let the house dry out for several days. Then they sub contracted a wood floor guy to come in, sand the floors down, and refinish them.

Maybe six months later, I noticed the filler used between the wood slats on the floor was starting to come up. I was told this was because we used wood heat as our primary heat source, which dried out the floors. The company agreed to come back to refill those cracks. It took maybe three months for that filler to start coming up. When I called about this, I was given several excuses; the filler was cracking because of my dogs' nails on the floor, the floors were in bad shape to begin with, the floors were old to begin with (the house was built in the 40's and I was told the floors were salvaged from an old school gym floor). I'm just wondering; should the floors have been replaced to begin with? The extent of my knowledge of wood floors is what I have seen on HGTV, but I do know when wood floors are rained on on any home restoration show, that's it, they start over. I have pictures but I'm not sure how to upload them.

Any advice or input would be greatly appreciated. Thanks!

Floors that have been flooded or have been wet for some time will swell. Since wood expands when it gets wet, the boards press against each other. This pressure adds up with more surface area affected which can collapse cell walls. The board is all there, but is now narrower. The gaps between the boards can be filled with a wood patch and will stick and act like wood. What promotes the filler falling out or being vacuumed away is dirt between the boards before the filler is applied, or movement between adjacent boards. If care is taken as the floor dries out gaps can be scraped and loose boards can be fastened down more securely so the sub-floor holds the boards so they move in unison when the floor gets deflected from being walked on which keeps the filler from cracking away from the edges of the boards. The floor must be completely "dry" before the repair is made or the boards will continue to shrink as they dry out creating gaps between the dried filler, also. Most older floors were installed with a minimum of fasteners. Top-nailing the floors before sanding with power cleats, or finish nails will help to keep the floors fastened well enough so that the filler does not "pop" out.
It may be that your floor work was not done very well. You only have to call your home owners insurance agent to find out if you have coverage since you have a "loss". All losses are not apparent at the time of the first claim.

Thank you, that helps. It was also suggested to me that the tongue and groove was compromised when the floors sat wet and no longer fits together properly, resulting in the cracks. Does this also sound like a possibility? Do you think the fact that we use a wood stove and have two dogs is contributing to the cracks?I'm sure we aren't the only house to have a wood fireplace and we keep our dogs' nails trimmed, but these are the excuses I hear. We also have planks that are peeling wood chunks (not the finish, the actual wood is peeling away--I wish I could figure out how to post pictures.) and it's only certain planks that this is happening to, not like an entire area if that makes sense? Any idea why that would happen? Again, I'm told it's normal wear & tear (after just six months?!) and blame also goes back to the dogs.

Thank you for your time, I really appreciate your input!

When floors get soaked there may have been shakes that now are raised up from the swelling. Shakes are a defect in the flooring that should have been culled out before the flooring was installed because they may create a splinter that can penetrate the skin if one catches on it wearing socks. A shake would look like the wood is delaminating. Just a thin layer would seem to peel off of the surface.
The T&G could be harmed, the joint can become loose because of the wood cells being compressed from the pressure. The top part of the groove may have had enough pressure to cause the cupping that occurred to not go back down. When the wood dries out again there would be a gap that will not go away. A loose section would not hold wood patch and eventually break loose showing the gap again.
A wood stove can dry the area around the stove from radiant heat and will dry the air out sometimes which is normal during the winter with any heat source.

Thank you so much. That's a lot of good information and I really appreciate it!