Mortar is a pretty useful binding material when it comes to building brick masonry units. You can use it to seal the gaps between bricks. Heck, you can even use it to repoint an old brick wall.
Irrespective of how you intend to use brick mortar, there is one common issue that’s pretty annoying. And that’s when brick mortar turns to sand.
Apart from being irritating, this form of brick-mortar failure is also expensive because it’s a waste of resources.
If you have a project where the brick mortar is turning to sand, I’ll be taking you through the main causes, the remedies, and how you can prevent this problem in the future.
What Causes Brick Mortar to Turn into Sand?
There are a couple of culprits that can be responsible for this problem. They include;
1. Using the Wrong Water to Mortar Ratio
The leading cause of brick mortar turning into sand is using the wrong water-to-mortar ratio. In a typical mortar mixture, the preferred ratio is 1 water: 2 cement and 3 sand.
This, however, differs depending on the mortar brand you’re preparing. If you use too much water or too much sand, there is a high chance that as it dries, the mixture will turn sandy.
So, if you deviated from the above ratios, that could be the reason why your brick mortar is turning into sand.
2. The Mortar Brick Was Rained on Before Hardening
Accidentally, if the mortar on your brick was rained on while it’s still fresh. That means that the water ratio was unintentionally increased, thus affecting the recommended ratio.
That could also cause the mortar to turn to sand. It’s a good idea to always check the weather forecast before applying mortar to brick.
3. Moisture was Sucked Out of the Fresh Mortar Before Drying
Have you always wondered why people dampen bricks with water before repointing them with mortar? Well, the reason behind that is to prevent the brick from sucking moisture out of the mortar.
Bricks have a diffusion-open surface that easily absorbs moisture. So, if you apply the mortar directly, it can suck the water from the fresh mortar, leaving behind cement and sand particles.
The environment can also suck moisture from fresh brick mortar. If you apply mortar to brick on a day when the humidity levels are low, moisture in the mortar can easily escape into the air, failing.
4. You Used an Old Mortar Mix
Like all other materials, mortar loses some of its properties with time. If you used an old bag of mortar on your bricks, then it may fail and turn sandy.
For every project, always use a new bag of mortar. That’s the only way you can be assured of avoiding such a problem.
5. Cleaning the Brick Wall with an Acidic Detergent
You may think that using an acid cleaner on a brick wall will remove all dirt and impurities. But you may end up doing more harm than good. Did you know that acid can burn mortar and cause it to turn sandy?
When the mortar is burnt by acid, it’ll often turn dark, as well. So, this is another sign you should look out for. Darkening occurs when acid interacts with iron compounds found in Portland cement.
How Do You Repair a Brick Wall Where Mortar Has Turned into Sand?
To repair a brick wall where mortar has turned into sand, you’ll need to perform a procedure known as repointing.
This is when damaged mortar is removed and replaced with fresh mortar. Here is a step-by-step guide on how to approach this issue;
Step 1 – Remove the Old Mortar
It can be tempting to want to apply fresh mortar over the damaged one, but I wouldn’t strongly advise you against doing that. Grab a chisel and a hammer and start chipping old mortar.
Make sure you wear a mask and some safety goggles. Finish up by cleaning debris from the brick joints or gaps.
Step 2 – Pour Some Water on the Bricks
To prevent the brick from sucking moisture from mortar, dampen them with water from a hose pipe. Also, make sure that the humidity levels are moderate.
Step 3 – Mix the Mortar According to Manufacturer’s Instructions
This step is very important. Most, if not all mortar bags come with instructions about the recommended water-to-mortar ratio. Please adhere to that ratio strictly.
Step 4 – Apply the Mortar and Give It Enough Time to Dry
Apply the mortar to the gaps and shape it as you see fit. Please work on one area at a time because some mortars have a quick drying period.
Even though mortar dries within 24 hours, I’d advise you to give it a few days. During that time, ensure that it’s wet.
If you follow all the instructions, I have shared with you, this time around, your brick mortar will not turn sandy.
What Happens When Brick Mortar Turns to Sand?
As you may already know, mortar contains a significant amount of sand which is mixed with Portland cement and water. When it turns sandy, the mortar degrades and loses its key properties.
For instance, it becomes loose and falls off easily with the touch of your fingers. When this happens, the mortar becomes unable to bind bricks together, because it has lost its strength.
Generally, when brick mortar turns to sand, it becomes useless. It won’t be able to bear the load of bricks and neither will it offer its initial aesthetic benefits.
After mortar turns into sand, there isn’t much you can do to fix it other than remove and replace it with fresh mortar.
I get it, such an occurrence can be a huge setback. However, the best thing you can do to is learn from previous mistakes and avoid them in future projects.
How to Prevent Brick Mortar from Turning into Sand?
Before I wrap up this review, I’m going to leave you with a few tips on how to prevent brick mortar from turning into sand.
I understand how irritating and costly such a situation can be. So, here are some ways you can prevent this problem;
• Always use new and quality mortar. The higher the quality, the lower the chances of failure.
• Ensure the mortar is damp during the drying period.
• Be very careful with the ratios when mixing mortar and water.
• Choose a suitable day for applying mortar to brick. It shouldn’t be too cold or hot. The same applies to humidity levels.
• Wet the concrete before applying the mortar.
• Frequently inspect the brick mortar and repair it asap.
• Do not introduce harsh cleaners to your brick mortar, especially the acidic kind.
Can Harsh Weather Turn Brick Mortar into Sand?
Unfortunately, harsh weather conditions like regular freeze-thaw cycles can degrade mortar into the sand. This won’t happen overnight.
But the longer brick mortar is exposed to freeze-thaw cycles, the quicker it breaks down into sand particles.
So, if you live in an area that experiences adverse weather conditions, it would be best to use a mortar with advanced properties. That’s the only way you can counter the adverse effects of weathering.
It’s also important to note that strong UV radiation can break down the bond inside brick mortar particles. When it comes to weather, there aren’t any prevention tips.
However, the good news is that these effects won’t happen quickly. It may take years or even decades and by then, the brick mortar would have served you for long.