Water logged wood will first swell then shrink as it dries out.
Reparing gaps hardwood floors wood fill.
When to avoid wood fillers.
Another exacerbating condition is water damage.
This type of cracking is considered normal for hardwood and no filler method will hold up unless the proper humidity is maintained.
Set the angled tip of the tube into the gap and pull the trigger.
Different gap repair methods.
It should help the filler to go in between the boards a bit more evenly.
The problem is magnified when the boards were not tightly laid in the first place.
Ordinarily you can fill the gaps with wood filler putty or with pieces of rope and then finish with stain to match the floor.
You may be tempted to fill the gaps with a wood filler.
Unfortunately this is not a permanent fix for boards affected by humidity as the boards will continue to expand and contract.
Before you begin filling gaps in old wood floors with caulk make sure you have properly inserted the tube into a standard caulk gun.
Now you are ready to actually correct the gaps in your hardwood floor.