Why is my plasterboard cracking?

Asked By: Zakiya Kolijn | Last Updated: 5th February, 2020
Category: hobbies and interests woodworking
4.6/5 (261 Views . 45 Votes)
If the walls are plasterboard, then hairline cracking is common, running vertically or horizontally along the joints between adjacent sheets. It usually occurs because the sheets of plasterboard were butted-up too tightly to each other.

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Then, what causes plasterboard to crack?

Fluctuations in temperature and humidity levels can cause framing members and drywall to expand and contract, resulting in cracking. Like other wall cracks, these can be re-taped and painted.

Similarly, is it normal for plaster walls to crack? Vertical and horizontal cracks in drywall or plaster walls typically indicate drying and shrinkage, which is normal after construction. Jagged cracks, stair-step cracks and 45-degree angle cracks generally signify structural movement or settling issues that are occasionally serious but usually harmless.

Also asked, how do you fix cracks in plasterboard?


  1. Spread the Joint Compound. Stir up the joint compound, then put a small portion on the edge of the six-inch taping knife.
  2. Apply Tape to the Crack. With the 6-inch knife, press the paper tape into the wet area, directly over the crack.
  3. Apply Joint Compound Over the Tape.
  4. Finish the Repair.

Do cracks in walls indicate a structural problem?

Most small cracks in drywall or plaster walls are not serious and are caused by seasonal expansion and contraction of the wood framing in your house over time. Larger cracks in your walls, however, can indicate structural or foundation problems.

26 Related Question Answers Found

When should I be concerned about cracks in plaster?

Cracks which are referred to as 'hairline' cracks aren't typically a major issue. There are various causes such as 'blown plaster'. This is where the plaster has lost contact with the wall.

The main time you need to worry about cracks is:
  1. They appear.
  2. You fill or plaster over them.
  3. They come back.

How do you know if a wall crack is serious?

Larger cracks that display these characteristics may indicate weaknesses in your property's foundation:
  1. One side of the wall is higher than the other.
  2. Doors and windows no longer close in their frame.
  3. Cracks are wider than about 5mm (or half a centimetre)

Are vertical cracks in walls bad?

The simple answer is yes. Vertical cracks are usually the direct result of foundation settling, and these are the more common of foundation issues. Horizontal cracks are generally caused by soil pressure and are normally worse than vertical cracks.

When should I be concerned about cracks in walls?

Horizontal Cracks
Vertical cracks run the same direction as drywall, generally making them less serious. If the crack is horizontal or runs at a jagged 45-degree angle, it might mean there's a more serious problem such as severe foundation shifting or water damage.

How do you fix large cracks in walls?

Fixing Drywall
Use a utility knife to cut a 1/8 inch to 1/4 inch V-notch along the length of the crack. Vacuum out loose material. Cover the crack with either mesh joint tape or joint compound and paper tape, followed by a thin layer of joint compound, extending about 2 inches on each side of the tape. Allow to dry.

How do you stop plaster walls from cracking?

You should not use sand that lacks fine material and if it does then you should add some lime into the cement. However, one sure way to prevent shrinkage cracks particularly is with the use of fibres in the mix, which will take some of the force of the movement through the material.

How do you fix cracks in walls before painting?

#2 How to Repair Wall Cracks
  1. Use a stiff putty knife to scrape the wall around the crack.
  2. Now use the sharp point of the knife to cut into the crack.
  3. Use a caulk gun to apply caulk (make sure it is paintable) into the crack.
  4. Cut a piece of fiberglass mesh tape a bit longer than the crack.

How do you fix shrinkage cracks?

Use the corner of the filling knife to widen the cracks you wish to fill. Drag the edge of the knife through the crack, raking out a little of the plaster to make sure that the gaps are large enough to push filler into. Run a dry paintbrush along the crack to brush out any loose dust.

Why is my plaster wall cracking?

Crack is a line on the surface of something along which it has split without breaking apart. Cracks in plaster walls are generally caused as a result of settlement, vibration or atmospheric conditions, but some may due to faulty construction. Let me explain briefly the reasons that lead cracks in plaster walls.

Why is my new drywall cracking?

Causes of Drywall Cracks
Cracks form due to stress placed on the seams. These cracks tend to occur around high-stress areas like windows, door frames, and corners. This stress can come from many sources. Temperature fluctuations can cause the drywall to expand and contract creating stress that cracks the seams.

Why are my drywall joints cracking?

When a house settles or walls move, drywall seams may crack if there is a "weak link". One reason for cracking is because the wrong type of drywall mud was used to the tape to the drywall seams. Some drywall tapers say that mesh tape should never be used in drywall taping because it is not as strong as paper tape.

How do you fix an uneven corner of drywall?

The same procedure works on edges around outside corners that are too uneven to finish.
  1. Fill a gap wider than about 1 inch, either on a flat or corner seam, with a strip of drywall.
  2. Fill a gap less than 1 inch wide with patching compound.

What causes walls to crack?

Causes of Wall Cracks In Your Home
Some common causes of wall cracks include: Humidity – Wood frames in most older homes expand and contract when the humidity rises and falls. This in turn puts stress on the plaster or drywall in front of it. The stress levels of your interior walls eventually lead to cracking.