Cracks in walls? Here's how to determine if they are serious (and what to do about them)
Cracks in walls come in all shapes and sizes. Here’s a guide to help you understand which cracks are serious and what you can do about them.
So you’ve discovered cracks in your walls
If you’ve recently uncovered some cracks in the walls of your house, or if the size and/or quantity of cracks has increased to such an extent that you’ve decided to do some research, the first thing to do is remain calm! You’re not alone.
Plenty of houses crack. We’re going to help you understand if they are likely to be superficial or serious. And what steps you can take to identify the root cause and whether further action is needed. Some of these things you can DIY. Other parts you’ll need help with.
Track your cracks
The first thing to do is to identify how many wall cracks you have throughout the building (internal and external), how big they are are and track their progression if they are growing. This will generally require you to grab:
a tape measure or ruler
a camera (or phone with camera)
a pen and notepad
You can also download our Crack Checker below:
#1 Measure each crack
At each crack in your house, have your camera at the ready. Place a ruler over the crack for scale (or get someone else to hold it there) and take a photo of the crack. Note the following on your notepad (or use “text markup” on your phone to add notes to the photo):
How wide is the crack (hairline or in mm)?
How long is the crack (end to end)?
How much change? Has it increased in size? If so, how rapidly?
Ideally you should keep an eye on these cracks and continue to note any changes in the future.
#2 Rate the seriousness
The Australian Standard AS2870-2011 provides guidelines for classification of damage to walls that is helpful to this situation, as follows:
Hairline cracks [less than 0.1mm] - classed as negligible. No action needed
Fine cracks [less than 1mm] - very slight and do not need repair
Slight cracks [less than 5mm] - noticeable but can be easily filled
Moderate cracks [5mm to 15mm OR several cracks 3mm or more in one group] - cracks can be repaired, possibly a section of wall may need replacing, doors and windows may be sticking, service pipes may fracture.
Severe cracks [15mm to 25mm, but also depends on number of cracks] - expensive repair work is required.
Where do each of your cracks rate?
From the hundreds of cracked wall assessments we’ve done and cracked wall data we’ve reviewed, we can add the following guidance to the Standard:
If you have hairline cracks, no action is needed, but don’t ignore them. Monitor them and take action if changes occur.
If you have a single crack greater than 5mm OR if you have several cracks each greater than 3mm, then you have a potential serious situation on your hand. We would recommend contacting one or more experts for further advice and get some options - see the next step.
Source: AS 2870-2011
#3 Seek expert insight
If you identified one or more “potentially serious” cracks or groups of cracks in step 2, we recommend you contact one or more structural engineering professionals to get specific advice on your situation.
To avoid paying for structural reports you don’t need, we provide an initial free home assessment aimed at reviewing the cracks first hand. We come to your property and conduct a review of the building inside and out, take levels and ascertain whether you require a paid structural engineering assessment (and report).
For 1 in X requests we get for a home assessment, we are able to determine from photography and other data provided that no further action is necessary.
For 1 in X homes we do a free home assessment on, we determine that no further action is needed.
It is a great way to get expert recommendations before opening your wallet.
Next Steps?
⇢ Download the Crack Checker here
⇢ Use the Crack Checker to check any cracks on your hoe, using the guidelines in this article
⇢ Get in touch with us with any questions you have or to get a complimentary home assessment