Drywall Cracks: Settling, Humidity or a Bad Tape Job?

Not every crack is a foundation problem. How to read the location and shape of drywall cracks in a Florida home, and how they get fixed so they stay fixed.

A crack in the drywall makes people think about the foundation, and occasionally that is right. Far more often the crack is telling a smaller story: the house moves a little with temperature and humidity, a truss lifted in the attic, someone rushed the taping, or a door has been slammed a few thousand times. Reading where the crack is and what shape it takes narrows it down quickly. Here is what we look for in Polk County homes, and how each kind is repaired.

Cracks at the corners of doors and windows

Diagonal cracks running from the top corner of a door or window opening are the most common crack in any house. Openings concentrate the stress of normal seasonal movement, and drywall joints often land right at those corners. They show up in new homes in the first couple of years as the framing dries and settles. Unless the crack is wide, growing fast or the door has stopped closing, it is cosmetic.

Cracks along the ceiling line

A straight crack where the wall meets the ceiling, or a gap that opens in winter and closes in summer, is often truss uplift. Roof trusses in a hot Florida attic expand and contract differently from the walls below, and the ceiling drywall lifts slightly at the interior walls. It looks alarming and is structurally harmless. The fix is not more mud; it is a floating corner detail or crown molding that hides the movement.

Straight cracks along a joint

A perfectly straight crack running horizontally at four feet, or vertically at a regular spacing, is a drywall joint that was not taped well. The tape lost its bond, or the joint was finished with mud but no tape at all. Common in older repairs and in garages and closets that were finished quickly. These are fixed by cutting out the failed tape and re-taping the joint properly, ideally with mesh or paper tape and setting compound.

Nail pops and small round bumps

Drywall screws or nails that have backed out as the framing dried, pushing a small circle of mud off. Cosmetic, easy to fix by driving the fastener below the surface, adding a second one nearby and patching.

Cracks in ceilings

A ceiling crack with a stain is a leak, and the leak is the problem. Our post on ceiling stains covers it. A ceiling crack with no stain, especially a long one across a large room, is usually a joint on a slightly sagging ceiling or, in a two-story home, the floor above flexing. Textured ceilings crack along the drywall seams because the texture is rigid.

When a crack deserves a closer look

• Cracks wider than about an eighth of an inch, or ones you can fit a coin into.
• Cracks that keep growing after being repaired, or that reappear in the same spot.
• Stair-step cracks in an exterior block wall with a matching crack inside. Our stucco crack guide covers the outside.
• Doors and windows that have started to stick or that no longer latch, with cracks at their corners.
• Cracks in the floor tile that line up with cracks in the wall.
• A floor that has become noticeably out of level.

Any of these together suggests movement beyond the normal, and it is worth having a foundation or structural professional look before the drywall is patched. Patching over it hides the evidence. We will tell you when a crack is outside what a repair should cover.

How a drywall crack is fixed properly

1. The crack is opened into a shallow V so the compound has something to hold, and any loose tape or mud is removed.
2. The joint is taped. Mud alone over a crack fails within a season; tape bridges the movement.
3. Two or three coats of compound, feathered wide, sanded between.
4. The texture is matched. Orange peel and knockdown are common in Central Florida homes and each takes a specific technique.
5. Primer over the repair, then paint the whole wall or ceiling so the patch does not flash. Our guide to patching drywall goes into the finish work.

For cracks that keep coming back

A crack at a joint that moves seasonally can be finished with a flexible joint compound or a paintable elastomeric filler that stretches instead of cracking. On truss-uplift ceilings, crown molding fastened only to the ceiling floats over the gap. These are the honest fixes for movement that is normal and will not stop.

Cost in the Lakeland area

Individual crack repairs are a small job, and doing several in one visit is far more economical than one at a time. Repainting the wall or ceiling to hide the repair is the main variable. A free estimate includes a look at whether the crack is a symptom of something larger.

Inventive Home Improvement repairs drywall as part of our handyman services and painting across Lakeland, Winter Haven, Lake Wales and all of Polk County. Call (863) 633-5499.

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