When you spot a crack in a ceiling, it might be easy to brush it off as something minor and cosmetic caused by the movement of the house and its foundations. But what if there is a bigger issue at hand that is causing the ceiling crack that you need to repair?
Causes of Ceiling Cracks and How to Fix them
Ceiling cracks can be caused by the following:
- Temperature changes
- Foundation shifts
- Changes to the load on the ceiling
- Structural problems in your house
These can cause any materials used in the construction of your home to expand (with heat) and contract (in cold).
This is a normal occurrence, and when roofs and ceilings are built, the joists are built in such a manner to allow some movement. Plasterboard and gyprock are less flexible construction materials though, so movement can cause the ceiling and wall to crack.
House foundations can shift as a natural occurrence, and this will depend on the footings of your house, and the ground upon which it is built. Sandy areas and houses with concrete slabs will move differently to weatherboard houses or heritage houses with wooden floors that are built on concrete stumps.
Bigger foundation shifts that can cause ceiling and wall cracks to occur are earth tremors. You don’t have to be in or near an earthquake line, for this to impact you, it happens naturally, and these have been felt in homes in Perth and surrounds before.
Changes to the load on the ceiling
Renovations, extensions, the placement of heavy furniture or a new bathtub on an upper level of a house, or even changes to the roof (think of air conditioning installations or a switch from a tin colorbond roof to a tiled roof) can all add additional load onto the ceiling.
As pressure goes on to the ceiling, it may crack under pressure. If there is significant bowing in the ceiling and deep cracks, you will want to see if structures are being put under additional stress and address the problem before you end up with a crack that has decided to become a gaping hole.
Structural problems in the house
Depending on the age and materials used to build the house, a structural problem can cause cracks in your ceilings and walls. For example, and unidentified termite infestation that eats away at load-bearing beams and formwork can make ceilings unstable, crack, and worse case, collapse.
A home’s version of crow’s feet, cracks due to age that appear in your ceiling or on your walls will look more like broken pieces of spider webs. It is when these cracks become larger and more pronounced and are no longer fine lines that you will definitely want to take some action.
One thing to look for as you monitor the movements in your house is when ceiling cracks are accompanied by wall cracks, and it’s a good idea to monitor them
Ceiling Cracks Accompanied by Wall Cracks
Where a ceiling and wall crack meet up, it’s likely to be a sign of structural issues that need addressing, particularly if the crack is large.
Not only can cracks allow other problems to start occurring (think termites getting into wooden formwork and loadbearing walls)), they can become costlier the longer they are left.
A few fine cracks scattered around walls and ceilings may be more cosmetic and just a sign that the house has moved due to heat and the paint has been affected, however, deeper cracks can mean deeper problems.
With the appearance of any cracks, its good to monitor them. Take photos, and use a pencil to mark and date the crack to see if it widens, or moves in a certain direction. It can be useful to keep photos saved on your phone should you decide that an expert is required for ceiling crack repair work
Cleaning and Taping a Ceiling Crack
Should you decide to DIY, or assess that the crack is more cosmetic, you will want to clean and tape the ceiling crack.
To do this, start by scraping away any dried paint or debris from the area with a plaster knife. Sand the area surrounding the area, as this will need repainting with ceiling after the crack is repaired.
Next, use a damp cloth to clean the area so that any dust is out of the way, as when it comes to repainting the ceiling, you want a nice smooth finish, not one with lumps of dust on the ceiling.
After the area has dried, you will want to use a product like 5-minute mud, spakfilla or similar to patch up the crack. Speak to your local hardware store to find the right product, as a ceiling made out of different materials may require a different repair compound.
Patching the Crack with 5-Minute Mud
To repair the ceiling crack with 5-minute mud (or similar), apply the compound along the crack and be sure to let it set.
If the crack is between two sheets (gyprock or plasterboard), you will need to hold the sheets in place with appropriate screws and make sure that the sheets are even and level. A spirit gauge will be able to assist you to make sure that the sheets are even and flush. It might be a good idea to get someone to assist you with this.
Once you have finished applying the compound, and it is smooth, apply some tape over the repaired crack.
You will then apply a little more compound over the tape. The role of the tape is to provide some extra reinforcement.
Finishing the Repair
To finish repairing the ceiling crack, you will need to wait for the compound to dry, and then sand the ceiling surface to be smooth.
Clean the surface down once again to remove any dust with a damp cloth, and allow the surface to completely dry.
Next, prime the surface and be ready to paint the ceiling to match.
If the crack reappears, and you feel it is more than a cosmetic crack, it might be time to call upon a professional to look at where the underlying issue is coming from.