How to Tell If , Foundation Cracks , Are Minor or Major Problems.br Lifehacker recently offered readers some tips for br identifying if cracks in a foundation are harmless br or something that impacts structural integrity.br Here are some of the br warning signs that experts br recommended looking out for.br Non-threatening cracks are generally small, br not larger than an eighth of an inch, br and don't allow moisture through.br Another sign of a harmless crack br is that it doesn't grow up br or down or to either side.br Many harmless cracks can be caused br by flaws in the curing process br and don't require maintenance. .br Cracks to be concerned about can appear damp, br will be wider than an eighth of an inch or show br some type of movement or change in size.br Similarly, diagonal cracks, cracks that travel from one br corner of a wall to another corner, or any vertical cracks br that appear below the soil line should be addressed.br Similarly, diagonal cracks, cracks that travel from one br corner of a wall to another corner, or any vertical cracks br that appear below the soil line should be addressed.br Other warning signs of a foundation issue include doors br or door frames that are out of alignment, a tilt in the slope br of a floor or dampness in a basement or crawlspace.br Other warning signs of a foundation issue include doors br or door frames that are out of alignment, a tilt in the slope br of a floor or dampness in a basement or crawlspace.br If in doubt, it's always best br to have a professional inspect br any cracks you find in your foundation.