Sealing a concrete slab can be beneficial in many scenarios. Here are some reasons why you might want to seal a concrete slab:

1. Protection Against Stains: Sealing helps protect the concrete from stains caused by oil, grease, chemicals, and other substances, making it easier to clean and maintain.

2. Water Resistance: Sealed concrete is less porous, which means it is more resistant to water penetration. This can prevent damage from freeze-thaw cycles in colder climates, which can cause cracking.

3. Durability and Longevity: Sealing a concrete slab can enhance its durability and extend its lifespan by protecting it from wear and tear.

4. Improved Appearance: Sealing can enhance the appearance of the concrete by adding a glossy finish and enriching the colour, if the concrete is stained or coloured.

5. Dust Reduction: Sealing can reduce the amount of dust produced by the concrete, which is especially beneficial for indoor spaces like basements and garages.

6. Mold and Mildew Prevention: By reducing moisture penetration, sealing can help prevent the growth of mold and mildew on the concrete surface.

However, there are also considerations to keep in mind:

– Cost: Sealing adds an additional cost to the project, both in terms of materials and labor if you hire a professional.

– Maintenance: Sealed concrete will require reapplication of the sealant periodically, depending on the type of sealant used and the amount of traffic the area receives.

– Surface Preparation: Proper surface preparation is crucial for the sealant to adhere properly. This might involve cleaning, repairing cracks, and ensuring the surface is dry.

In summary, while sealing a concrete slab is generally beneficial, the decision should be based on the specific conditions and requirements of your project. For high-traffic areas, places exposed to harsh weather, or spaces where appearance and cleanliness are important, sealing is often a good investment.