Reasons for cracks in walls | How to repair?

cracks in walls or buildings are the most common occurrence either in new buildings or in the old buildings. cracks in walls are an eyesore.

So to repair these cracks, we have to understand the types of cracks and reasons for cracks in walls.

Here wall refers to either dry masonry wall or plastered wall or concrete wall, and the reasons and remedies are different for these walls.

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Reasons for cracks in walls

Generally, the cracks in walls are caused by the natural settlements of the house over time, so you can repair your house easily with some simple tools, But If the cracks appeared on the drywall is severe and if there are large settlements in the ground. Then contact a qualified building professional before repairing the dry masonry wall.

Here are few reasons for cracks in walls;
  • Heavy moisture content; When water leaks into the house then walls may swell, rot, and gets weaken. So this causes the wall to crack and crumble. moreover, fungus or algae starts growing on the walls.
  • Weather changes; Expansion and contraction of structural members due to varying in temperature can cause, cracks on walls.
  • Heavy objects; It’s obvious that cracks may form in the walls due to stress caused by hanging heavy loads.
  • settling; Due to the settlement of building or ground, the cracks will appear on the walls.
  • poor drywall installation; There should not be visible joints, uneven corners, sagging ceilings.

Assess the cracks?

If the cracks are structurally serious and If you couldn’t encounter as soon as possible then your whole structure will fail.

so, remember the following signs while checking for structural cracks;

cracks in walls
  • cracks will run horizontally or zig-zag or 45 degrees direction and not vertically.
  • Doors and windows don’t shut properly in their frames.
  • The cracks width will be greater than 1/4th of an inch.
  • Cracks will form frequently and in large amounts.
  • The cracks may try to expand in the upper or lower direction.

If you are not sure of cracks that appear on walls, then don’t take any risk. Please do contact a qualified building professional for an inspection.

How to repair cracks in walls?


Mesh joint tape
  • First ensure the crack is repairable or not then, using a knife expand the crack to 1/8th of an inch or 1/4th of an inch V-notch along the crack line.
  • Using a brush clean the loose material present inside the crack.
  • Now, cover the crack completely using a mesh joint tape or paper tape. Then apply a thin layer of the compound joint to the edges of the tape up to two inches on each side.
  • Allow it to dry then, apply the second coat of compound joint on the crack up to approximately 6-7 inches on either side of the crack.
  • Allow this compound to dry overnight and using a fine sand paper sand the surface.
  • so now, The wall is ready for painting.

Plastered wall

  • The plaster wall has some extra layers to the drywall, It is constructed using two layers of outer plaster and Inner wooden or metal lath.
  • SO, to repair cracks that appear on the walls, we have to check whether the crack is smaller or wider.
  • Smaller cracks are repaired in a similar way as done in the case of drywalls. But to repair larger cracks we need other techniques to follow.
  • To know more about; How to repair large cracks in the plaster wall? , click here

concrete wall

  • The cracks in walls (concrete) are common due to contraction and expansion, poor workability, shrinkage, poor workmanship, etc…
  • But cracks due to the settlement of ground and foundation are serious issues to consider.
  • To remove these types of cracks we use an epoxy repair kit.
  • First cut the crack in the shape of ‘V’ and clean the crack using a brush to remove dirt, so our crack will be ready for patching and cleaning. Now according to the manufacturer’s direction, mix the epoxy sealant.
  • Then based on crack width apply the sealant. If the crack is wider use a backer rod and then fill the crack.

so be sure to check the crack type before you work on it because structural cracks need professional assistance.

Deep cracks

To repair cracks deeper than 1/4th of an inch, for better results, you have to fill the void first with a compound joint and then plaster the crack with mesh joint tape or paper tape.

Follow the previous steps mentioned in drywall.


From the above discussion, we are able to know the reasons for cracks in walls. Also you learned about repair methods of drywall, plaster wall and concrete wall.


Assess the cracks properly, because structural cracks are dangerous and need certified building professional.

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K Vinay Goud

My name is k.vinay. I am a civil engineer from India. I know there were many people who struggle for information during graduation or after seeking their job. I have started this website for providing basic knowledge and New technologies which were implementing all over the world. we will definitely provide valuable information for you all. stay connected and Follow us on other social media platforms. Thank you !