A window or door is essentially a hole in the wall, which makes it a structurally weak area. So when there is any stress in the wall—such as from settlement, uplift, or lateral movement of the soil under the home—the crack that relieves the stress is most likely to occur at the “hole." Also, the window or door has a different rate of thermal expansion and contraction than the wall surrounding it, which adds to the stresses that build up around its perimeter. 

    But small diagonal cracks, emanating from the corners of doors or windows at a wood-framed wall, especially at the interior side, can just be caused by wood movement from seasonal moisture changes in the wood framing and trim. They might shrink during the winter. 

    The indications that a structure is moving, shifting, unstable, or even in failure, can sometimes be easy to miss. See our article How do I recognize serious structural problems in a house? to learn what to look for. To delve further into structural issues, read What causes cracks in the walls and floors of a house? for a brief course in crackology. 

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    If your concern is about a specific crack pattern, go to these blog posts: 

• What causes stair-step cracks in a block or brick wall? 

• What causes a horizontal crack in a block or brick wall?  

• How can I tell if a diagonal crack in drywall at the corner of a window or door indicates a structural problem?  

• There's cracks running along the home's concrete tie beam. What's wrong?  

• How can I tell if cracks in the garage floor are a problem or not? 

• Why is my stucco cracking?

• How can I tell whether my house foundation problems are caused by a sinkhole or expansive clay soil?

     Visit our EXTERIOR WALLS AND STRUCTURE  page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.