How to repair cracks in plasterboard ceiling

Want to know how to repair cracks in plasterboard ceiling? You’re not alone. Cracks in ceiling plasterboard are a fairly common nuisance, and while they’re usually caused by the normal settling of houses, they can sometimes be a cause for concern.

Depending on where the cracks are located and how big they are, they could be an indicator of structural damage. They could also be a sign of poor workmanship or even moisture damage.

No matter your situation, by the end of this article you’ll be able to determine the cause of the problem, know how to repair cracks in a plasterboard ceiling, and whether it’s safer to call in a professional.

What causes cracks in ceiling plasterboard?

There are several possible causes of unsightly cracks in your plasterboard ceiling, including:

• Structural movement. Homes settle over time, which is a normal type of movement that can sometimes result in cracks in your ceiling. Building materials can also expand and contract due to temperature and humidity changes
• Poor installation. Another common cause is poor quality craftsmanship during the installation process, such as improperly used joint tape, installing plasterboard seams over studs, or insufficient nailing or screwing
• Age of the material. Plasterboard becomes more brittle and susceptible to cracking as it gets older, so it may be the case that your plasterboard needs replacing if it’s showing signs of age-related deterioration
• Moisture and humidity. Excessive moisture in the air, or water coming from a leak in the roof or a plumbing issue, can also weaken plasterboard and cause it to crack
• Other factors. There are a few other possibilities, such as if the material was low quality to begin with or if the plaster was improperly mixed. Or, you could even have a light fixture that’s too heavy, leading to cracks around points of stress concentration

If you’re struggling to identify the cause of the issue and want some professional help, simply add your postcode into the search box below to find local experts.

Should I be concerned about the cracks in my ceiling?

If you’re looking for how to repair hairline cracks in plaster ceiling, age-related cracks, or isolated incidents, such as one or two small cracks without any other signs of damage, the problem is likely cosmetic and not a major cause for concern.

Some signs that the problem is more serious and may be an indicator of structural issues include:

• Large or expanding cracks. If the cracks are wide and getting bigger, this could be due to damage or structural movement
• Multiple cracks. Large numbers of cracks or cracks that appear in clusters, can be signs of a more serious issue
• Water damage. If you’re aware of a leak or plumbing issue that may have affected the ceiling, then you notice cracks, this could be telling of a significant problem
• Location of cracks. Cracks appearing near the corners of walls and around the edges of doors and windows can be a hint of structural issues
• Accompanying symptoms. If you notice cracks along with other symptoms of structural problems, such as floors becoming uneven, doors sticking and windows jamming, you should get in touch with a structural engineer as soon as possible

Here’s how much you can expect to pay for a structural engineer. Enter your postcode into the search box below to find the local contractors who come highly rated.

How to repair cracks in plasterboard ceiling

Whether you’re looking for how to repair a small hole in a plasterboard ceiling or a hairline crack, here are the steps to take:

Required tools

• Utility knife
• Joint compound
• Paper or fibreglass mesh tape
• Sandpaper (medium and fine-grit)
• Paint and primer
• Putty knife or joint knife
• Ladder
• Paintbrush or roller
• Dust mask and safety goggles

Step one: Preparation

Firstly, prepare the area and put on your dust mask and safety goggles.

Move any furniture and other obstructions out of the area and lay down your drop cloth to protect carpets from paint and debris.

Step two: Assess and open the crack

Inspect the crack to determine how wide and deep it is, as this will give you a better idea of how to repair it and how much material you’ll need.

Take your utility knife and widen the crack slightly, carving it into a shallow V-shape. This allows you to remove any loose material and provides a better surface for the joint compound to stick to.

Step three: Clean and apply tape

Clean the crack by removing any leftover debris with a cloth or handheld vacuum. This also helps the joint compound adhere to the surface.

Measure and cut some fibreglass tape so it’s long enough to cover the length of the crack. Position it over the crack and press down firmly to glue it in place, ensuring it’s completely flat with no bumps.

Step four: Apply joint compound

Grab your putty knife and scoop out some joint compound. Apply a thin layer over the mesh tape, pressing firmly to fill the V-shape and ensure it sticks to the surrounding plasterboard.

Smooth it out with the flat edge of the knife, trying to keep it as evenly spread as possible. Once you’ve applied the joint compound, allow it to dry according to the manufacturer’s instructions, which is typically overnight.

After it’s completely dried, apply a second layer of joint compound, making it a bit thicker this time. Extend the material slightly beyond the boundaries of the first layer to make it blend in better with the surrounding area.

Finally, let this layer dry too.

Step five: Sand the surface

Once dry, sand the surface with a medium-grit sandpaper to remove any rough or bumpy spots. Then, take a fine-grit sandpaper and repeat the process. Wipe away any dust so the surface is ready to be painted.

Step six: Prime and paint

Before painting, apply a coat of primer to the area, feathering the edges to help it blend in. Let the primer dry according to the manufacturer’s instructions, then apply a coat of paint.

You may need to repaint the whole ceiling to achieve a uniform look, or you may get away with painting a larger area than that of the repair site.

Step seven: Final touches

Finally, remove the drop cloth, put your furniture back in place, clean up any dust or debris, and dispose of waste materials. Congratulations, you’ve repaired your plasterboard ceiling.

For more complex or serious issues, or if you don’t think you can manage the task yourself, don’t hesitate to contact a local expert. They will ensure a high-quality, professional job and potentially prevent future problems too.