I am remodeling bathroom. Floor had mold which resulted in floor rot. Anyway, I cut it out and replaced most of the hole...however there is still a hole next to tub ( about 1inch wide by 4 inches long) and very jagged as you can tell. You will be able to tell the new floor and the old floor as well. I also have a couple small cracks as my measurements weren't the best. Are the small gaps ok to have? I will be putting backboard on next. I do not have any access from below. Thanks and any help would be greatly appreciated!