Home Improvement Ideas Remodeling Advice & Planning Maintenance & Repairs How to Fix Ceiling Cracks Patch ceiling cracks before they grow with our step-by-step guide. By Timothy Dale Published on February 19, 2024 Trending Videos Close this video player Photo: Getty Images / Cunaplus_M.Faba Project Overview Working Time: 3 hours Total Time: 1 day Skill Level: Intermediate Estimated Cost: $25 to $50 Most homeowners take pride in keeping their homes in good condition, but damage can still occur. Ceiling cracks are one common issue. Minor cracks can appear due to something as simple as a temperature change or fluctuation in humidity levels. Water damage can also cause a ceiling to crack, and is typically a sign of a bigger underlying problem. Use this guide to learn how to recognize the type of ceiling crack, how to determine the cause, and how to fix ceiling cracks before they can spread. How to Determine the Severity of Ceiling Cracks Not all ceiling cracks should be handled by a DIYer. Before starting a repair project, inspect the ceiling crack to determine the severity of the damage. Depending on the type of crack and the cause of the damage, it may be better to call a professional. Types of Ceiling Cracks Learning the type of crack can help when assessing the cause and severity of the damage. Ceiling crack types include hairline cracks, straight cracks, discolored cracks, spiderweb cracks, deep cracks, and cracks between the ceiling and the wall. Hairline cracks can generally be repaired by a DIYer. These thin cosmetic cracks are usually caused by fluctuations in the temperature and humidity. Depending on the size of the crack, it may even be able to be fixed with nothing more than a new coat of paint. Straight cracks are another type of crack that is relatively easy to patch. These cracks typically run along the edge of the drywall tape and appear as a result of shrinking plaster, poor workmanship, or an insufficient amount of plaster. Discolored cracks are usually due to water damage. While DIYers should be able to handle minor cracks and discoloration, depending on the severity of the water damage, this may be a job best left to the professionals. It's recommended to call a plumber to determine the source of the water damage and make repairs before patching the ceiling. Spiderweb cracks will typically appear as a result of poor workmanship and can be patched by an experienced DIYer. However, in some cases, larger spiderweb cracks may be due to the foundation settling, which could have more serious implications for the structural integrity of the home. Contact a professional to assess the damage and make repairs. Deep cracks should not be handled by a DIYer. Long, deep cracks are a sign of major structural damage that should be dealt with as soon as possible to prevent the ceiling from collapsing. Cracks between the ceiling and wall may be a result of the roof truss moving, shifting, shrinking, or expanding due to temperature or humidity. These issues can be fixed by a DIYer. However, if the cracks run along the ceiling and continue down the wall, then this is a sign of structural damage and should be assessed and repaired by a professional. Causes of Ceiling Cracks There are a range of reasons for a ceiling to crack, including damage from above, poor workmanship, water damage, or even structural damage. Consider these possible causes of ceiling cracks to determine the best course of action to repair a cracked ceiling. Damage from above can put a crack or even a hole in the ceiling, which is why it's important to be careful when moving around in the attic. Someone stepping in the wrong place or dropping a heavy item could cause significant damage to the ceiling. Poor workmanship can result in many minor issues, like improperly taped joints or an inadequate amount of drywall compound. When this occurs, cracks can appear, but most DIYers should be able to patch these damages. Water damage is a serious issue that is often due to an active leak. A plumber should be able to locate and fix the leak, but the damaged ceiling will still need to be patched. Water damage may also be caused by a serious spill, overflowing toilet, or a flooded tub, shower, or sink. Structural damage is the worst possible cause of ceiling cracks. This means that something has occurred to affect the actual structural stability of the home. If structural damage is left unresolved, it could lead to the crack spreading or even the collapse of the ceiling. Contact a professional if you suspect the ceiling crack is due to a structural problem. How to Make an Uneven Ceiling Flat What You'll Need Equipment / Tools Utility knife Ladder Drywall knife Drywall saw Measuring tape Drill Circular saw Putty knife Sandpaper Paint roller Paint tray Materials Drywall joint compound Adhesive drywall tape Drywall Plywood Drywall screws Primer Ceiling paint Instructions How to Fix Ceiling Cracks Prepare the Area Lay down a tarp, piece of plastic, or a drop cloth in the area where you will be working to catch any falling debris. It's also a good idea to remove any furniture from the room to keep it free of dust and paint. Next, set up a ladder, making sure that all four legs can stand flat on the ground and that you can reach the ceiling without standing on the top two steps. For some homeowners, this means using a large, A-frame ladder, while other homeowners may only need a step ladder to reach the ceiling. The 11 Best Step Stools of 2024 Cut Out Cracked Drywall and Take Measurements If the ceiling only has a minor crack, skip to Step 5 to continue with the repair. If there is a wide crack or even a small hole, then it's necessary to cut out and replace the damaged part of the ceiling. Use a drywall saw to cut out the area of the crack. Measure the opening in the ceiling and the distance between the joists. If possible, it's recommended to access the damaged ceiling from above, through the attic. However, if you cannot get into the attic or there is flooring from the floor above covering the damaged ceiling, you will need to work from below. Prepare Plywood Backer Board and Replacement Drywall Plywood backer board will provide solid support for the replacement piece of drywall. Measure and cut a piece of 1/2-inch plywood so that it fits between the ceiling joists and completely covers the hole in the ceiling by about 2 to 4 inches on each end. Use a utility knife to cut out a piece of replacement drywall that fits as close as possible to the hole in the ceiling. Make sure the replacement drywall is the same thickness as the existing ceiling, otherwise the patch will be uneven with the rest of the ceiling. Secure Backer Board and Replace Drywall If you have access from above, simply drop the backer board into position. Similarly, if you only have access from below, rotate the backerboard until it can slide through the hole on the diagonal, then adjust the position of the plywood until it sits over the hole. Drive a couple of screws through the backer board and into the joists at an angle to hold the plywood in place, then install additional screws through the existing drywall and into the plywood. Next, slide the replacement drywall into the hole and secure it to the backer board with drywall screws. Clean the Ceiling Crack and Apply Drywall Tape If there is any loose material or damaged drywall remaining around the ceiling crack, use a drywall knife to scrape away this material, then use a damp rag or cloth to wipe down the area. This should get rid of any debris that may otherwise prevent the drywall tape from adhering properly. Apply the adhesive drywall tape directly over the crack. If you had to cut a hole and install a drywall patch, then apply the adhesive drywall tape over the gaps between the drywall patch and the existing ceiling. Avoid applying more than a single layer of tape to any one area. Apply Joint Compound Use a putty knife to apply the joint compound over the damaged area. Spread the joint compound thinly, but make sure that it completely covers the drywall tape. If you apply too much joint compound, it may be too heavy, causing the joint compound to fall off the ceiling. If you don't apply enough, the drywall tape and drywall screws may show through the patch. Sand the Joint Compound Until Smooth Give the joint compound about 24 to 48 hours to dry, then use sandpaper to remove any high spots and smooth out the repair. If you find any areas where the joint compound is too thin or completely missing, apply more joint compound, allow it to dry, then sand it until the patched area is smooth. Prime and Paint the Ceiling After the joint compound is completely dry and sanded down, the next step is to prime and paint. Start with a suitable primer for the ceiling, then switch to a ceiling paint that matches the existing ceiling. Alternatively, you can paint the entire ceiling to ensure that the patch doesn't stand out. When to Call a Professional It's recommended to call a professional if the ceiling damage is too great or if the cause of the ceiling crack is due to structural issues or severe water damage. A trained professional will be able to assess the situation and suggest steps to repair the problem. Similarly, it's a good idea to hire a plumber to inspect water damage and track down the leak. The cause of the water damage must be resolved before fixing the ceiling. Additionally, if the ceiling has multiple cracks or you notice that the ceiling is bowing, these are signs of a serious structural problem. Depending on the extent of the issue, there is even a risk of the ceiling collapsing, so you should immediately leave the room and contact a professional.