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Unfortunately, even the highest-quality rendering jobs can be susceptible to cracking over time due to exposure to the elements, settling and structural shifts.
When you notice a crack, it’s best to get it repaired as soon as possible so that it doesn’t get bigger and, therefore, more challenging to repair.

Continue reading to learn more about the types of cracks that appear in render and how to repair them.

Why Does Render Crack?

Render can crack over time due to several reasons. These factors include:

  • Water evaporating from the render too quickly during the application process.
  • Moisture becomes trapped between the external wall and the render.
  • When a home settles into its foundation, minor cracks can appear.
  • Significant temperature changes like freezing and thawing can cause materials to expand and contract, forming cracks.
  • Foundation issues like settling, sinking and shifting often cause diagonal and horizontal cracks.
  • If the render or structural construction is of poor quality, it can result in structural weakness, which can cause a multitude of problems, including cracking.

Different Types of Cracks

The following types of cracks can form in your render:

Hairline Cracks

Probably the most common crack you will see in your render. Hairline cracks are very thin and are mostly considered superficial and not a major structural concern. They are mainly caused by temperature changes or the structure settling.

The solution includes minor work like a fresh coat of paint or refilling them with a caulk or spackle mixture.

Horizontal Cracks

Horizontal cracks are usually more serious. They can run parallel to the ground and are a sign of problems with the building’s foundation or structural integrity.
If you see horizontal cracks in the render, the best thing to do is to contact a structural engineer who may undertake major foundation repairs and install retaining walls or drainage systems.

Vertical Cracks

Vertical cracks run up and down the wall and can differ in length and width. They are often caused by minor shifts in the foundation or by the natural settling of the building.

The repair process depends on the length and width of the cracks. They may require a more simple solution like sealing or a more extensive structural repair.

Diagonal Cracks

Diagonal cracks can be a troubling sign of movement within the structure due to stress. The angle of the crack can usually provide an answer as to the cause.
Again, the solution depends on the angle and size of the crack, but foundation reinforcement or repairs might be required.

Stairstep Cracks

Stairstep cracks are so-called because they resemble a set of stairs. They are often a sign of foundation shifting or settling.

Usually, sealing a small stairstep crack is enough, but if the cracks keep appearing or get larger, they may need a more in-depth solution, like tuckpointing (using two contrasting colours in the mortar joints of brickwork) or looking at the structure foundation itself.

Spiderweb Cracks

Spiderweb cracks are fine cracks that spread out from a main spot and resemble a spiderweb, thus their name. They can be caused by the foundation settling, moisture and age.

Spiderweb cracks can be patched up relatively quickly with a plaster repair kit. However, it’s crucial also to resolve the underlying cause.

Settlement Cracks

Settlement cracks are narrow vertical cracks that are caused when the ground beneath a structure isn’t compacted enough.

If the cracks are small enough, they can be sealed and painted over. For larger cracks, strengthening the foundation by using underpinning may be required.

Structural Cracks

Integrity issues with the structure can cause structural cracks due to ground shifting, poor construction or extreme load.
These cracks are quite serious and will require a structural engineer’s help to carry out underpinning, partial reconstruction or reinforcement.

Thermal Expansion Cracks

Thermal expansion cracks form when materials expand and contract when the temperature changes.

Expansion joints or the use of materials that are designed to withstand thermal shifts are a common solution.

If you notice a crack or cracks in your render, it is best to call a professional to prevent further damage. At Sydney Cement Rendering, we’ll be more than happy to come out and inspect your render to determine what type of crack you have and the right solution to fix it.

We take pride in being Sydney’s trusted rendering experts and providing our customers with the highest quality rendering services. Contact us at 0402 704 984 or visit our website: to find out more about what we offer!