Laitance is a weak, easily-crumbled layer that forms on the surface of concrete. It is caused by the migration of cement and fine aggregates to the surface of the concrete as it cures. Laitance can be a problem because it can make the concrete surface weak and uneven, and it can also prevent other materials from adhering properly to the concrete.
There are a number of benefits to removing laitance from concrete. First, it can improve the strength and durability of the concrete surface. Laitance is a weak layer, so removing it can make the concrete surface more resistant to cracking, chipping, and other damage. Second, removing laitance can help to improve the adhesion of other materials to the concrete. This is important if you plan to apply a coating, sealer, or other finishing material to the concrete. Third, removing laitance can help to improve the appearance of the concrete surface. A smooth, even concrete surface is more aesthetically pleasing than a surface that is covered in laitance.
There are a few different ways to remove laitance from concrete. One common method is to use a scarifier. A scarifier is a machine that uses rotating blades to abrade the surface of the concrete. This removes the laitance layer and exposes the underlying, stronger concrete. Another method of laitance removal is to use a shot blaster. A shot blaster uses high-pressure air to propel small, abrasive particles at the concrete surface. This method is more effective than scarifying at removing laitance, but it can also be more expensive.
The best time to remove laitance from concrete is after it has cured for at least a few days. This will give the concrete enough time to develop its strength, but it will not be so hard that it is difficult to remove the laitance. If you are planning to apply a coating or sealer to the concrete, you should remove the laitance before applying the coating. This will ensure that the coating bonds properly to the concrete and that it will not peel or crack over time.
Laitance removal is a relatively simple process that can be done by a professional concrete contractor or by a DIY homeowner. If you are concerned about the strength, durability, or appearance of your concrete, removing laitance is a good way to improve it.
Here are some additional benefits of laitance removal:
- It can help to prevent efflorescence, which is a white powdery substance that can form on the surface of concrete. Efflorescence is caused by the migration of dissolved salts to the surface of the concrete. Removing laitance can help to reduce the amount of salts in the concrete, which can help to prevent efflorescence.
- It can help to improve the fire resistance of concrete. Laitance is a good conductor of heat, so removing it can help to make the concrete surface more resistant to fire.
- It can help to reduce the noise level in a concrete structure. Laitance can absorb sound waves, so removing it can help to make a concrete structure quieter.
If you are concerned about any of the potential problems caused by laitance, it is a good idea to have your concrete professionally inspected. A concrete contractor can assess the condition of your concrete and recommend the best course of action for removing laitance.
Conclusion
Laitance removal is a simple process that can have a number of benefits for concrete. If you are concerned about the strength, durability, appearance, or fire resistance of your concrete, removing laitance is a good way to improve it.