Ceiling cracks are one of the most common home maintenance issues, and one that a lot of people have questions about. A big crack across the ceiling can look quite scary, but is it really a big problem? What causes different types of cracks? Can I fix cracks myself or do I need a professional?
This article will answer all of those questions and take you through the different types of ceiling cracks, so you know how to deal with them if they do appear.
Are Ceiling Cracks a Cause for Concern?
Any changes in your home, especially cracks, deserve your attention. Whether they are a cause for concern or not ultimately depends on the type of cracks and what causes it. Some cracks are just cosmetic and happen because of natural movements in the home, while others are warning signs of a much bigger maintenance issue. The key is understanding the different types and being able to tell which ones you should be worried about.
8 Types of Ceiling Cracks
1. Plaster/Drywall Cracks (Hairline Cracks)
Hairline cracks in plaster and drywall are one of the most common types of ceiling cracks. They are very fine cracks, not much bigger than the width of a hair. The good news is, hairline cracks are not usually a cause for concern. They need to be fixed but they don’t suggest any major damage. However, if you notice them getting bigger, that is more alarming. You should also be concerned if there are other issues, like a sagging ceiling, alongside the hairline cracks.
What Causes Drywall Cracks in Ceiling?
Usually, hairline cracks are caused by fluctuations in temperature or humidity. They are surface level cracks in the plaster or the paint, and don’t run any deeper into the wall. If the temperature or humidity changes a lot, this can cause expansion and shrinkage. Over time, this weakens the plaster and causes the hairline cracks. If there are multiple coats of paint on the ceiling, this increases the chances of hairline cracks. The expansion and contraction has the same effect on the paint and causes it to crack.
Hairline cracks also occur because of the slight movements in your home. Large shifts are a cause for concern but all houses will experience a small level of natural movement, which sometimes causes hairline cracks. New homes are more likely to have hairline cracks as they settle and shift slightly.
How to Fix Drywall Cracks in Your Ceiling?
The good news is, repairing drywall cracks is very easy. A small crack less than half an inch long can be patched with some drywall spackling compound. Use a putty knife to spread the spackling into the crack and smooth it over. Once it is dry, you can use 100 grit sandpaper to sand it until it is flush. Finally, just paint the ceiling again and it will be as good as new.
In some cases, a fresh coat of paint will fill the cracks and cover them. However, it’s better to be on the safe side and use some spackling compound to fill the crack first.
How To Stop Hairline Cracks From Coming Back
It’s frustrating if you fill hairline cracks and paint over them, only to discover that they keep coming back again. This is quite common because you patch the cracks but don’t actually deal with the root cause.
If the cracks are caused by natural shifting of the building, you can’t do much about it. However, if they are coming back quickly, it’s likely that they are caused by humidity and temperature fluctuations. Using a humidity detector and a dehumidifier to help you manage the humidity levels may help here.
Poor quality paint is also more likely to crack. If you have a problem with hairline cracks, use a thicker, better quality paint next time.
These fixes may help you reduce the appearance of hairline cracks but, unfortunately, you can’t always avoid them so you will just have to repair them when they appear.
2. Water Damage Cracks (Discoloring)
Water damage in your ceiling can cause a lot of damage, including cracks and discoloration. If you have water damage cracks, you will see a lot of uneven cracks and holes in the ceiling, usually with some stains. If the cracks have been forming for a while, there may be black mold growing in the area too.
Water damage cracks themselves are not a sign of structural problems with the building. However, they are a sign of a more serious problem that needs to be fixed right away. Some of the related issues like mold can cause a lot of health problems too, and you may experience dangerous electrical faults if water leaks onto the wiring, so never ignore water damage cracks in the ceiling.
What Causes Water Damage Cracks In Ceiling?
As you’d expect, water damage cracks are caused by an excess of water. This may be from a burst pipe that is leaking into the ceiling. It can also be caused by condensation build-up on the ceiling.
In some cases, it’s not the plumbing that is the issue, it’s the roof. Holes in the roof let rainwater in and it soaks into the walls and ceilings, leading to water damage cracks. If you don’t deal with this right away, you’ll end up with water damage throughout the house.
How to Fix Water Damage Cracks in Your Ceiling
Before you start fixing the ceiling, you need to tackle the source of the water. If you suspect it’s a leaking pipe, check your water usage. If your bill is much higher but you haven’t changed your usage, you almost certainly have a leak. A drop in pressure can be an indication of a leak too. Call a plumber to take a look and fix any leaking pipes before turning your attention to the ceiling.
You should also check the roof to make sure there are no holes or loose tiles that are letting water in. Once you have identified and dealt with the source of the water, give the ceiling a few days to dry out, just so you can be sure that there are no more leaks.
When the ceiling is dry, you can repair the plaster with some joint compound. Follow these basic steps to fix the water damage cracks:
1. Remove Damaged Areas – All of the plaster and paint that has been soaked through with water need to be removed. You can use a putty knife or scraper to break away all of the loose material. Make sure that the whole area is smooth and even before you start patching.
2. Fill The Cracks – Use the joint compound to fill in cracks and small holes. Use the putty knife to smooth the joint compound into the cracks and holes, scraping off the excess to get a smooth finish. Bear in mind that if the damage is extensive and you have large holes and cracks, you may have to replace a section of the ceiling, in which case it might be best to call a contractor.
3. Cover The Surface – Once the cracks and holes are filled and the compound has dried, you need to apply a thin layer over the top of the area to seal it. Use the same joint compound and leave it around 15 minutes to dry between coats. Two thin layers is enough to cover the surface.
4. Sand The Area – When it is dry, you can sand the area with a 120 grit sandpaper to smooth the area, then wipe it clean with a damp cloth.
5. Prime and Paint – Finally, put a coat of primer on the ceiling and then paint over it. If the damage was caused by excess condensation, use a waterproof paint to prevent more damage in the future.
How to Deal With Mold Caused by Water Damage
Often, you will have mold in the same area as water damage cracks, especially if you have neglected the problem for a while. You can get rid of light to medium mold stains quite easily. If you go to the hardware store or look online, you can get mold cleaners designed for this purpose. Simply spray them on, let them sit for a while, and then wipe it clean.
If the mold is covering a large area of the ceiling and normal mold cleaning products won’t work, you may have to call in a professional mold repair company.
3. Drywall Joints/Taping Cracks (Straight Cracks)
Straight cracks that run across the ceiling are usually cracks along the joints between two pieces of drywall. When the drywall is installed, there are seams between the sheets, which are filled with drywall mud and covered with tape. However, this doesn’t always hold properly and you start noticing straight cracks along the seams.
If the crack is fairly thin, it isn’t a cause for concern. It doesn’t look great, but it’s likely caused by something minor. However, if the crack is more than a quarter inch wide, it could be a sign of more serious foundation damage and you should get it looked at. Similarly, a straight crack that runs along the ceiling and then continues down the wall signifies foundation damage and should never be left alone.
What Causes Drywall Joints/Taping Cracks in Ceiling?
There are a few things that cause cracks along the joints between drywall. This is a weaker spot that is naturally prone to cracking anyway, and other factors can speed the process along.
Firstly, the drywall could be improperly installed. Using mesh tape instead of paper tape reduces stability and increases the chances of cracking. Using the wrong type of drywall mud can also contribute.
As the home gets older, foundation settling can create cracks in the ceiling. It’s natural for the foundations to shift slightly over time. However, if you notice a lot of straight cracks appearing in a short space of time, keep an eye on it and call somebody to have a look if the cracks get wider because you could have serious foundation damage. High humidity levels cause contraction and expansion, which adds to the settling effect and causes more cracks.
Finally, heavy items in the rooms above the crack could be to blame. If something heavy is placed right over a seam, it weighs it down and causes the tape to pull away from the seam. This is quite common with heavy free standing bathtubs, but it could be caused by any kind of furniture. It’s worth looking at furniture arrangements and moving things around a bit if you get a lot of cracks.
How to Fix Drywall Joints/Taping Cracks in Your Ceiling
To fix straight cracks on the ceiling, you simply need to reapply the tape and refinish the joint properly. Follow these basic steps:
1. Clean the Drywall Joint – Use a scraper to pull away any loose bits of paint and drywall compound around the joint. Work along the crack, only taking off the loose bits that come away easily, don’t start ripping the whole ceiling down. Once you have cleared it, you should be able to peel away the old joint tape fairly easily.
2. Fill the Crack – Use drywall joint compound to fill the crack. Spread a thin layer over the crack, about 3 inches wide, so you have a good amount either side. Make sure that you get into the crack and spread it evenly so it is flush with the ceiling.
3. Apply Joint Tape – Next, the joint tape is applied over the top of the compound while it is wet. Put the tape over, making sure to get the joint right in the center, and then push it down with a putty knife.
4. Apply More Joint Compound – When the tape is in place, apply another thin layer of joint compound over the top. Spread the edges out to make sure that all of the tape is covered. Do this carefully so you don’t move the tape in the process.
5. Sand, Prime, and Paint – Let the joint compound dry and then gently sand it down to remove any rough areas. The more careful you are with your application, the less sanding you will need to do at this point. You can then prime it and paint the ceiling and it will look as good as new.
Which Drywall Joint Tape Should You Use?
Using the right tape will help you prevent more cracks in the future and there are two main types to choose from; paper and mesh. Overall, paper is the better choice. It’s more durable and it dries hard like papier mache, so you get a solid repair that is less likely to crack in the future.
However, mesh tape is much easier to use. Mesh tape has an adhesive backing, so you can stick it straight over the seam, rather than sticking it with joint compound. That said, paper tape is easier to apply in corners because mesh tape doesn’t bend that well.
I would suggest using paper tape and taking the time to do it properly. It’s a little trickier, but the end result will be better and you will be less likely to get more cracks. That said, mesh tape is better at resisting moisture, so if you think that high humidity is making cracks appear, it might be a better choice.
4. Spreading Cracks
Spreading cracks, sometimes called spiderweb or crawling cracks are very fine cracks that sprawl out across the ceiling in an uneven spiderweb pattern. These are very easy to identify because there are lots of small cracks, rather than one large one. Usually, they are simply a cosmetic issue and shouldn’t be a cause for concern. If they are 1/16th inch thick or less, you can easily fix them yourself. But if they start growing larger than this, you should get them checked out by a professional because it could be a sign of more serious damage.
What Causes Spreading Cracks in Ceiling?
There are a few causes of spreading cracks, but it’s often down to the natural movement of the building. If the building shifts and settles unevenly, you don’t get a single hairline crack moving in one direction, you get lots of small spiderweb cracks moving in different directions.
Sometimes, it can also be caused by the drywall mud being applied too thinly. It shrinks slightly as it dries, and starts to crack. If you have a textured ceiling and the drywall compound used to create the texture was laid on too thick, this can cause spreading cracks too.
How to Fix Spreading Cracks in Your Ceiling
The good news is, spreading cracks are incredibly easy to fix. All you need to do is mix up some drywall compound and spread a thin layer over the cracks with a putty knife. Then, let it dry and gently sand it smooth before painting. In some cases, a fresh coat of paint will fill the cracks, but they are less likely to come back if you fill them with drywall compound beforehand.
5. Wall and Ceiling Separation
Wall and ceiling separation is very obvious. You will notice a wide crack where the wall and ceiling meet, as if they are being pulled apart. Unfortunately, this one is usually caused by more serious structural issues and you need to get it repaired by professionals right away.
What Causes Wall and Ceiling Separation?
Sometimes, wall and ceiling separation is caused by cracking joints in the drywall. In this case, you can fix it in the same way that you would fix straight cracks running across the ceiling. Unfortunately, more often than not, it is caused by truss lift.
The trusses are the wooden frames in your roof that hold it up and maintain the shape and strength. They are made to be flexible so they don’t crack when the temperature fluctuates. However, this movement can sometimes cause problems in the rest of the house. If there are extreme changes to the temperature, or heavy winds cause a lot of movement in the roof, the trusses can pull upwards and lift the ceiling away from the wall, creating a large crack.
How to Fix Wall and Ceiling Separation
As soon as you notice wall and ceiling separation in your home, you should call a construction company. This isn’t an easy fix that you can do on your own. A construction company needs to do work on the trusses to make them more stable before fixing the cracks between the ceiling and walls.
If you simply fix the cracks in the ceiling without addressing the underlying problem, the cracks will reappear each year.
Can Truss Uplift Be Prevented?
Truss uplift is a difficult problem that can’t always be avoided. It is not caused by poor installation or mistakes on the part of contractors, it is just a problem with the way that trusses are designed. In areas with less temperature fluctuation, it shouldn’t be a problem. However, if you are experiencing problems with truss lift, contractors can install after framing. This framing replaces the standard paper joint that runs along the corner. Instead, a vinyl sheet is used and the drywall is drilled into this. It has more movement in it, so as the trusses move up and down each year, the cracks do not appear.
6. Sagging Ceilings
Sagging ceilings are very worrying because they look like they could collapse at any moment. If you noticed that the ceiling is very bowed and it dips in the middle a lot, you should be worried. The longer it is left, the more it will sag and the more dangerous it becomes. You also increase the chances of doing some serious damage to your home. So, even if you only notice a slight sagging or pillowing effect, you should take action immediately.
What Causes Sagging Ceilings?
Water damage is the most likely cause of sagging ceilings. Sometimes, it causes cracks and holes (as discussed earlier) but it can also collect in the ceiling without coming all the way through. It weakens the overall structure and causes it to sag. Insulation in the ceiling can absorb a lot of the water and become incredibly heavy, putting further pressure on the structure.
Unfortunately, sagging ceilings can be caused by poor workmanship too. If the home is not well-built and you are missing important load bearing beams, the ceilings will start to fall in on themselves. This problem will get worse over time as fixings and adhesives naturally start to fail.
Pests are another common cause of sagging ceilings. If termites get into the ceiling, they can eat through all of the load bearing beams and destroy the internal structure. Termites love moist, warm environments, so if you have a leak in the ceiling you can end up with water damage and termite damage at the same time.
How to Fix Sagging Ceilings in Your Home
When ceilings are sagging because of water bubbles, you may be able to fix it yourself. Start by dealing with the underlying cause of the water damage, and then you can turn your attention to the ceiling. Follow these steps to replace the damaged section:
1. Draw Around the Damaged Area – Start by drawing a large rectangle around the sagging area. Extend this area further than the damaged area, up to the rafters. It’s important that you take out enough so you are only left with non-damaged drywall.
2. Cut Out the Damaged Area – Use a drywall saw to cut the lengths perpendicular to the rafters. Then, use a utility knife to carefully cut parallel to the rafters so you can remove the rectangle of damaged drywall. If the insulation from the roof starts coming through, gently push it back up.
3. Cut a New Section of Drywall – Next, use the old piece of drywall as a guide to cut a replacement section. Measure the hole and the new piece to double check that you have the right size. Also, ensure that the new piece of drywall is the same thickness as the existing ceiling.
4. Attach the Drywall – Screw the new section of drywall into the rafters, spacing the screws around 6 inches apart.
5. Tape the Seams – use a putty knife to apply joint compound, and then cover with paper joint tape. Finally, spread another thin layer of joint compound over the top and smooth it. Once it has dried, lightly sand it smooth to prepare it for priming and painting.
This process will replace the sagging section and fix the issue. If a bit of water damage has caused the ceiling to bow, this is an adequate fix. However, if there are structural issues or pests that are damaging the underlying structure of the ceiling, replacing a sagging section of ceiling is just painting over the problem. You should always get a professional to take a look and deal with whatever is causing the ceiling to sag in the first place.
7. Floor to Ceiling Cracks
Floor to ceiling cracks are one of the most alarming types of cracks. If the crack runs along the ceiling and then continues all the way down the wall, this is usually a sign of more serious structural damage and needs to be dealt with straight away. If it is left, it can be very dangerous. As soon as you spot these cracks, stay out of the area and call a professional right away.
What Causes Floor to Ceiling Cracks?
In most cases, floor to ceiling cracks are caused by structural damage to the home. If the load bearing beams, joists, or stud walls are struggling to take the weight of the ceiling, the structure of the house shifts and cracks form. This is different from foundational shifting and damage, and can lead to extreme damage to your home.
What Are Other Signs of Structural Damage?
Floor to ceiling cracks usually come along with some other signs of structural damage you should look out for. The window and door frames are shifted, so you may notice that they don’t open and close properly. You may also spot cracks appearing above and below the windows.
If you have a tile or vinyl floor, look for cracks there too. The shifting structure will cause cracks throughout the room.
These signs, combined with large floor to ceiling cracks, are a sure sign of advanced structural damage. If you don’t do anything about it, you could eventually end up with a ceiling collapse on your hands.
How to Fix Floor to Ceiling Cracks
Floor to ceiling cracks are not something you can just patch up yourself. They are a sign of major structural damage that needs to be fixed by a professional construction crew. So, call somebody in to have a look right away. They will make the necessary structural repairs to stabilize the property first, and then patch the cracks in the walls. If you just fill the cracks yourself, they will keep coming back and the structure will continue getting weaker until, eventually it creates a very dangerous situation in your home.
8. Ceiling Holes
Ceiling holes usually have a very specific cause. They vary in size from very small, almost imperceptible holes, to much bigger holes a few inches wide. The size depends on the cause and how long you have left the holes without doing anything. Unlike a lot of cracks, holes are not caused by natural movements in the house and they are always an indication of a problem that needs to be tackled.
What Causes Ceiling Holes?
Pests are a potential cause of ceiling holes. If you have rodents or termites in the ceiling, they will chew through and you’ll see lots of holes appearing. If you are concerned about pests, get up into the attic and see if you can spot other tell-tale signs like droppings or chewing marks. Pests are more likely to take shelter in your attic during rainy periods when their nests are disturbed by running water.
If it’s not pests, it’s probably water damage. It’s easy to tell the difference between the two because holes caused by water damage will have yellow/brown stains around them. A large leak can cause the ceiling to crack and sag, but a very small leak that is just dripping onto the ceiling can leave a small hole.
How to Fix Ceiling Holes
There are two ways to fix a hole in the ceiling, depending on how large it is. Small holes that are less than an inch can be filled in the same way as thin cracks, with a putty knife and some drywall compound. Simply smooth it into the hole and let it dry, then sand it down.
However, larger holes that are bigger than 12 inches may need to be fixed with a new section of drywall. Follow these steps to patch it:
1. Remove Damaged Drywall – Locate and mark the joists in the ceiling, and then take a utility knife and cut away the section with the hole. Go right up to the joist beams and remove a rectangle section, with lots of excess around the hole.
2. Measure Replacement Drywall – Use the section you have removed as a guide to measure a new piece. Double check the dimensions by measuring the hole before you fix it in.
3. Screw in Replacement Section – Screw the replacement section of drywall into the beams.
4. Tape the Seams – Spread a thin layer of drywall joint compound into the seams around the new piece, and then lay paper tape over the top. Spread another thin layer of joint compound over the top and smooth it.
5. Sand, Prime, and Paint – Once the joint is dry, give it a light sand to smooth it and then you can prime and paint.
Medium sized holes that are bigger than 1 inch but less than 12 inches may not need a full patch. Instead, you can use a mesh patching material to cover it. Follow these steps to repair the hole:
1. Cut Away Loose Material – Use a knife to cut away loose material around the hole. Cut away a few extra inches beyond the hole so all of the damaged drywall is definitely gone.
2. Patch the Hole – Start by applying joint compound around the edges of the hole. Then, take your plastic mesh patching material and cut a square large enough to cover the entire hole. Press the patch into the joint compound and flatten it out. Then, put another thin layer of joint compound over the top of the entire patch.
3. Sand and Reapply – Sand the area down once it has dried and, if there are any uneven patches, add more joint compound to flatten it out.
4. Prime and Paint – When you are happy with the finish and you have sanded it smooth again, you can prime and paint the area.
What to Do if Your Ceiling is Cracked?
If your ceiling is cracked, you should first determine what type of crack it is so you can decide whether it’s a big problem or not. Small hairline cracks, sprawling cracks, and straight cracks on the ceiling can be fixed yourself and they are mainly cosmetic issues. But if you have big holes, water damage, sagging, or floor to ceiling cracks, you’ll need some professional help.
You should also check the size of the cracks because this is a good indication of the seriousness. Anything that is a quarter of an inch or smaller is likely to be ok. Once cracks get bigger than that, you should get them checked over.
What are Signs of a Foundation Problem?
Cracks can sometimes be a sign of foundation issues. If you have a lot of hairline cracks or floor to ceiling cracks, this is a sign that the foundations of the property are damaged. There are also other key signs to watch out for:
- Uneven floors
- Cracks in tile floors
- Uneven door and window frames
- Diagonal cracks around windows and doors
- Sagging ceilings and bowing floors
- Bowed walls
- Chimneys and porches separating from the house
Don’t ignore these signs, get the foundations checked right away when you spot them. The earlier you intervene, the cheaper and easier it will be to fix the problem.
Can I Patch My Own Ceiling Cracks?
Yes, you can patch your own ceiling cracks, as long as they are only cosmetic. Hairline cracks, spreading cracks, and straight cracks along the joints in drywall are all fairly easy to fix yourself. But if you have a more serious underlying problem causing the cracks, you need to call in a contractor to deal with it instead of simply patching over the problem.
What Products are Best for Fixing Ceiling Cracks?
You need drywall joint compound or spackle compound to fix most ceiling cracks. Spackle is closer to a filler and this is best for smoothing over hairline cracks or filling in small holes. If you need to repair the joints in the drywall, you’ll need joint compound (often called drywall mud).
DAP Wallboard Joint Compound is an excellent ready-mixed drywall mud that is perfect for taping up joints. It can also be used to fill in some cracks too because it’s quite a thin solution, compared with other joint compounds.
If you need spackle, 3M High Strength is a great option. It comes in 2 different options; large hole repair and small hole repair. This tough, easy to use spackling compound will fill most cracks in your ceiling easily.
Who Can You Call if Your Ceiling is Cracked?
When you are calling somebody about your cracked ceiling, you need somebody that can deal with the root cause rather than the crack itself. So, if you notice a lot of signs of foundation damage, call a foundation specialist. You may need a roofer if there are large cracks where the wall and ceiling meet, caused by truss lift.
Otherwise, you can call a general contractor to deal with things like water damaged ceilings or cracked joints.
The good news is, a lot of ceiling cracks are harmless and quite easily fixed on your own. That said, some of them can be an indication of a big problem, so you should never ignore them. If you are ever unsure about a crack, it’s better to be safe than sorry and get it checked out.
Jamie is the Founder of My Home Dwelling. He is a homeowner and enjoys sharing his homeowner tips with others. He has real estate experience working as a new home construction Realtor. Jamie has worked on numerous residential construction sites helping with interior and exterior renovations. He loves refinishing furniture, DIY home projects, and sharing his knowledge online.