How to Fix Cracks in Ceilings and Walls
Small cracks in walls and ceilings are very common, especially in older homes.
Most of the time they are cosmetic. Plaster moves, houses settle, temperatures change and small cracks appear over time. That does not mean they should simply be painted over.
If a crack is there, there is usually a reason for it. The first job is to look at the surface properly before deciding how to repair it.
One of the mistakes we see most often is filler being wiped over a crack and painted immediately afterwards.
It looks fine for a while.
Then the line comes back.
The problem is usually not the filler itself. It is the preparation underneath it.
We normally start by removing anything loose and opening the crack slightly where needed. Dust is cleaned out properly so the repair material has something sound to bond to.
It is a small part of the job, but it makes a big difference.
On one ceiling we worked on in Rathmines, the same crack had already been painted over several times. Once the area was opened properly, it was clear the surface underneath had never been dealt with correctly. The repair needed more than another coat of paint.
That is fairly typical.
Choosing the right filler
We use different materials depending on the crack and the surface.
For normal wall and ceiling repairs, products such as Toupret TX110 and Gyproc EasyFill are useful because they finish well and can be sanded cleanly once dry.
Very fine cracks around corners, skirting boards or other areas that may move slightly can be different. In those places, a flexible decorator’s caulk can sometimes make more sense than a hard filler.
The important part is not buying the most expensive product.
It is using the right one for the repair.
Once filled, the repair needs time to dry properly. We normally sand it back, check the surface again and apply another fine coat if the first repair has shrunk or still needs levelling.
Trying to rush this stage normally shows later.
A patch that has not dried properly, has not been sanded flat or has not been primed can remain visible even after the wall is painted.
Before applying the finishing coats, we prime repairs where required and make sure the surface is uniform enough to take paint properly.
That is what helps the repaired area disappear into the rest of the wall rather than looking like a patch.
Cracks around skirting, corners and windows
These areas need a little more judgement.
Skirting boards, architraves and plaster do not always move in exactly the same way. A rigid filler in the wrong place can simply crack again.
Where there is slight movement between surfaces, a flexible material is often the better choice.
We had a hallway in Clonskeagh where the line above the skirting had opened along a large part of the wall. The boards themselves were fine. The junction simply needed to be cleaned out, sealed correctly and repainted.
It is a small detail, but once it is repaired properly the whole hallway looks sharper.
That is really the point with this type of work.
Fixing cracks is not particularly complicated, but it does need patience.
Do not cover the problem and hope the paint hides it.
Clean it out.
Use the right material.
Let it dry.
Sand it properly.
Prime where needed.
Then paint.
If you are doing the work yourself, spend more time on the preparation than you think you need to. That is normally where the difference is.
And if a crack keeps returning, is getting noticeably wider or looks different from the normal fine plaster cracks you see around a house, it is worth looking into the cause before continuing to fill and repaint it.
For us, painting has always been more than putting colour on a wall.
The repair underneath still counts once the paint tin is closed.
Frequently Asked Questions
Can I just fill a crack and paint over it?
Sometimes, but only if the surface underneath is sound.
Loose plaster, dust or unstable paint should be dealt with first. If the preparation is poor, the crack can come back through the new paint quite quickly.
What is the best filler for cracks in walls and ceilings?
It depends on the repair.
We regularly use products such as Toupret TX110 and Gyproc EasyFill for normal plaster repairs. Around areas that may move slightly, such as skirting or corners, a flexible decorator’s caulk can sometimes be the better option.
There is no single filler that is right for every crack.
Why does the crack keep coming back after painting?
Usually because the movement or the original problem has not been dealt with properly.
Sometimes the crack was filled too quickly, sometimes the wrong material was used, and sometimes the surface underneath was never prepared correctly.
If the same crack keeps returning, we normally stop treating it as just a paint problem and look more closely at what is happening underneath.