Over time, weather conditions and general wear and tear can cause damage to the mortar joints between bricks, leading to cracks and deterioration. When faced with old brickwork in need of repair, one common solution is applying a skim coat of mortar mix. In this article, we will explore whether it is possible to apply a skim coat of mortar mix on old brickwork, the benefits and disadvantages of this technique, and the steps involved in completing the process.
Understanding Skim Coating on Brickwork
Skim coating refers to the process of applying a thin layer of mortar over existing bricks, typically less than 1/8 inch thick. This technique is commonly used for repairing damaged or deteriorated mortar on brick walls or other masonry surfaces. By applying a thin layer of new mortar, the skim coat helps protect the underlying bricks and reinforce the overall structure, while also providing a fresh and uniform appearance.
Determining Suitability for Skim Coating
Before considering applying a skim coat of mortar mix, it is crucial to assess the condition of the old brickwork. Various factors can determine the suitability of skim coating, including:
- Extent of damage: Skim coating is recommended for minor damage, such as hairline cracks or shallow mortar erosion. If the mortar joints are extensively damaged or if there are significant structural issues with the bricks, additional repairs or rebuilding may be required.
- Stability of existing brickwork: The bricks themselves must be in good condition and securely attached to the wall. If there is widespread movement or instability among the bricks, it is essential to address these issues before applying a skim coat.
- Moisture issues: Excessive moisture can cause problems when applying a skim coat. It is crucial to identify and resolve any moisture-related issues, such as leaks or water seepage, before proceeding with the skim coating process.
Benefits of Skim Coating
Skim coating old brickwork offers several benefits:
- Improved appearance: A skim coat provides a fresh, uniform look to the old brickwork, revitalizing its overall appearance and increasing curb appeal.
- Increased durability: By filling in cracks and damaged areas, the new mortar layer adds strength and helps protect the underlying bricks from further deterioration.
- Cost-effective: Compared to extensive repairs or complete replacement, skim coating is a more affordable option, requiring fewer materials and labor.
Steps to Apply a Skim Coat of Mortar Mix
If the condition of your old brickwork is suitable for skim coating, follow these steps:
- Prepare the surface: Thoroughly clean the brick surface by removing any loose debris, dirt, or existing loose mortar. Use a wire brush or scraper to ensure a clean and solid substrate.
- Mix the mortar: Following the manufacturer’s instructions, prepare a mortar mix suitable for skim coating. Ensure a smooth and workable consistency.
- Apply the mortar: Using a trowel, apply a thin layer of mortar mix over the old brickwork, filling in any cracks or gaps. Work in small sections at a time to maintain control and avoid drying out.
- Smooth and level: Once the mortar is applied, use a trowel or a sponge float to smooth and level the surface, ensuring a consistent thickness of the skim coat.
- Allow for drying and curing: Follow the recommended drying and curing time specified by the mortar mix manufacturer. This typically involves misting the surface with water periodically to prevent cracking while the mortar sets.
- Clean the surface: After the skim coat has fully dried, use a brush or damp sponge to remove any residual mortar from the surface, leaving behind a clean and uniform finish.
Skim coating can be a viable solution for repairing and improving the appearance of old brickwork. By carefully assessing the condition of the bricks and ensuring proper preparation and application techniques, a thin layer of mortar mix can help revitalize and protect the underlying structure. If you are uncertain about your ability to perform a skim coat or if extensive repairs are needed, consulting a professional mason is always recommended to ensure a successful and long-lasting outcome for your brickwork.