Transforming a raw stack of cinder blocks into a finished, high-quality surface is a common goal for both DIY enthusiasts and professional contractors. While the blocks provide structural strength, their rough, porous texture and inconsistent appearance often do not match the desired aesthetic or functional requirements. Covering cinder blocks with cement is a highly effective solution that creates a smooth, durable, and visually appealing finish ready for paint or tile.
Understanding the Purpose and Benefits
The primary reason to cover cinder blocks with cement, typically a mix of cement, sand, and water known as mortar or stucco, is to overcome the inherent limitations of the block itself. Cinder blocks are prone to moisture penetration and can look stark and industrial. Applying a cement layer seals the surface, protecting it from weathering and water damage, which is crucial for exterior applications. This process also allows for endless design flexibility, enabling you to achieve a sleek, modern look or a textured, stone-like appearance.
Essential Materials and Surface Preparation
Success in this project hinges entirely on proper preparation and using the correct materials. You will need a base mix of concrete mortar, a bonding agent to ensure adhesion, a hawk and trowel for application, and various texturing tools. However, the most critical step is preparing the cinder block surface. The blocks must be absolutely clean, dry, and free of dust, oil, and any loose debris. Any cracks or holes need to be filled with a patching compound to create a uniform substrate.
- Pressure washer or stiff brush for cleaning
- Mortar mix (cement, sand, water)
- Concrete bonding agent or primer
- Trowel, hawk, and finishing tools
- Protective gloves and eye gear
Step-by-Step Application Process
Begin by applying a coat of concrete bonding agent to the cinder block surface, following the manufacturer's instructions. This chemical layer creates a strong mechanical bond, preventing the cement finish from peeling or cracking. Once the bonding agent is dry, you can proceed with mixing your cement mortar to the correct consistency—similar to peanut butter for optimal adherence. Apply the mortar in small sections using the trowel, pressing it firmly into the surface to ensure a solid grip on the block.
Achieving the Perfect Finish
After the initial layer is applied, work quickly to smooth the surface with the trowel to remove ridges and create a flat plane. For a textured finish, you can use a sponge, brush, or special texturing tools while the cement is still wet. If you are aiming for a very smooth coat, a final pass with a steel trowel once the mixture begins to set will result in a polished, seamless look. It is vital to maintain consistent moisture levels; allow the surface to cure slowly by misting it with water periodically to prevent cracking.
Common Challenges and Solutions
One of the most frequent issues encountered is poor adhesion, where the cement finish pops off in sheets. This is almost always due to inadequate surface preparation or a failure to use a bonding agent. Another challenge is efflorescence, a white, powdery residue that can appear on the surface as water evaporates. While not harmful, it is unsightly and can be mitigated by using a vapor-proof sealer after the cement has fully cured. Addressing these issues proactively ensures a long-lasting and professional result.
Long-Term Maintenance and Protection
To preserve the integrity and appearance of your newly covered cinder blocks, a final protective sealant is highly recommended. A high-quality masonry sealer will repel water, resist stains, and protect the cement from UV damage if the application is exterior. Regular cleaning with a gentle detergent and a soft brush will keep the surface looking its best. By following these steps, you effectively turn a basic structural wall into a durable, attractive feature that enhances the value of your property.
