Cracks in Concrete Walls Can Be Very Serious
Cracks in your concrete walls of your foundation or in the walls of your home can become very hazardous over time.
If you have ever noticed cracks in concrete block walls in your home, then you may have asked yourself if it is something you need to be concerned about and whether or not you need to consider repair costs in the immediate future. This is something many people with homes that have visible concrete block walls have seen and wondered themselves.
Before you become overly concerned, there are some important pieces of information to be aware of when it comes to concrete block walls.
Common Causes of Cracks in Concrete Block Walls
There are a couple of common causes for cracks to form in concrete walls that are perfectly safe and accounted for.
- Shrinkage – This is actually expected by professionals. Concrete blocks are made using water and concrete mix. Blocks are allowed to dry for 28 days but it is entirely possible for concrete blocks to continue to dry and, therefore, shrink ever-so-slightly for up to years after this 28-day period.
Restraint tension – Again, this is expected by professionals. It is largely caused due to the natural shrinkage mentioned above. The difference is the shrinkage can create the blocks and wall being tugged a certain way they weren’t meant to be tugged. The blocks and walls can shift in minuscule ways to relieve this tension, creating some small cracks in concrete block walls.
When to be Concerned About Cracks in Block Walls
Your next natural question may be about when to be concerned about cracks in block walls. It is good to first understand the different types of cracks you may see and notice before talking about when to be concerned. Here are the three main types of cracking you may see:
- Horizontal lintel cracks – cracks that will go horizontally between concrete blocks and can form around the corners of the walls or around certain openings in the walls, like windows or doors.
- Vertical lintel cracks – the same as horizontal lintel cracks, but will crack vertically and around the same areas as horizontal lintel cracks but can also occur along reinforced cells, which are areas in the wall where reinforcements in the wall have started creating restraint tension (above).
- Stair-step cracks – these are cracks that will move diagonally along blocks in the concrete wall around corners and openings, as with horizontal lintel cracks.
Now that you have a better understanding of the types of cracks to look for you can understand when to be concerned about cracks in block walls. A professional needs to be determined when it is time to intervene since many cracks may, in fact, not affect the structural integrity of the wall. This professional may determine there has been a loss of contact between the wall and it’s foundation or if the wall is properly reinforced. In many cases, there is no need to be concerned unless you are able to see visual shifts in the walls or widening cracks in concrete block walls.
How to Repair Step Cracks in Block Walls
If you are noticing cracks in your concrete block walls and are wanting to repair them so they are more visually appealing, then you can follow these simple steps below. However, it is important to reiterate that, though these steps may show you how to repair step cracks in block walls they will not correct any loss of structural integrity. They will simply make the cracks in concrete block walls less noticeable or aesthetically pleasing.
- Assess and confirm the type of foundation cracking that has occurred – we have outlined some simple ways for you to assess cracks above.
- Get a high-quality polyurethane caulk and follow the packaging instructions for preparing to use the caulk – this will likely involve using a caulking gun and a small blade to cut the tip of the caulking tube.
- Fill the cracks with the caulk – be careful to get the caulk inside the crack and not just around the cracking.
- Use a gloved hand to gently dab the caulk along the crack to fill it in and blend the caulk with the concrete block – this will help the cracks in concrete blocks smooth out a bit and make them read to paint if that is what you decide to do.
- Continue to assess cracking – after you have repaired the hairline cracks you should keep an eye on the cracked areas to make sure they are, in fact, not worsening. If not, then all is well and you have successfully repaired the step cracks (or any other cracks) in your block walls!
