Repair in Practice: How to Fix Cracks on the Ceiling
Did you recently do a repair, and cracks have already appeared on the ceiling? We found out from an expert of the construction company «Good» about the causes of crack formation and how to eliminate them.
Vladislav Kosichkin — expert, development director of the construction company «Good»
Where and why do cracks appear? Cracks on ceilings and at the junctions with walls are typical for panel houses. This happens because the house settles, and vibrations occur between floors. In monolithic buildings, this does not happen if they were built in accordance with all standards and regulations. Over time, small cracks may appear on floors, but this is related to the drying of concrete during pouring.
Such cracks won't bring much trouble and will never reappear after being fixed, unlike cracks in panel houses. Movement of panels can continue for a long time after construction, usually within 5–10 years.
Types of Cracks- Micro-cracks. These can be sealed with acrylic sealant or finishing plaster.
- Deep cracks. These are eliminated with plaster, usually gypsum-based.
How to Remove a Crack? Cut the Crack Regardless of Its SizeCracks can be widened manually: using a specialized cutting tool or triangular scraper. Alternatively, use a grinder with an diamond disc. The depth of the cut should be no less than 5 mm.
Clean the crack and apply primer
This is necessary to reinforce the crack and ensure maximum adhesion with the material.
Fill the crack with plaster
Plaster should be applied in one go and no more than 15 mm thick to level the surface with the ceiling.
Seal the surface with linen or fiberglass cloth for reinforcement
The second option is more favorable because fiberglass cloth is denser than linen. Just don't forget to check which side you're gluing: the front side of fiberglass cloth feels smoother.
Apply finishing plaster
It is usually applied in a thin, even layer using a wide trowel.
Remove irregularities
Use sandpaper, but only after the plaster has dried.
Paint the ceiling
Paint can only be applied if the surface is perfectly flat.
