How to Remove Old Mortar from Bricks: A Definitive Guide
Removing old mortar involves a meticulous process that effectively cleans bricks for reuse or restoration. It typically requires mechanical removal using tools like chisels and grinders, followed by a chemical cleaning for stubborn residue, ultimately restoring the brick to a usable state.
The Importance of Removing Old Mortar
Bricks are durable and reusable, but the mortar that binds them eventually degrades. Removing old mortar is crucial for several reasons:
- Reusing Bricks: Recovered bricks from demolition or renovation projects are valuable resources. Removing old mortar allows these bricks to be reintegrated into new construction or landscaping projects.
- Repairing Existing Brickwork: When repairing walls, chimneys, or patios, removing deteriorated mortar is necessary to create a clean surface for new mortar to adhere to, ensuring a strong and long-lasting bond. This process is called repointing.
- Aesthetic Improvements: Freshly cleaned bricks look significantly better than those with crumbling or stained mortar. Cleaning and repointing can dramatically enhance the appearance of brick structures.
- Preventing Further Damage: Crumbling mortar allows water to penetrate, leading to freeze-thaw damage that can weaken the entire structure. Removing and replacing failing mortar is a preventative measure.
Tools and Materials Needed
Successful mortar removal requires the right tools and materials. Here’s a list of essentials:
- Safety Glasses: Essential for protecting your eyes from flying debris.
- Dust Mask or Respirator: Protects your lungs from dust and fine particles.
- Gloves: Protect your hands from abrasion and potential chemical irritants.
- Brick Hammer and Chisel: For manually chipping away mortar. A pointing chisel is preferred for precision.
- Angle Grinder with Diamond Blade: For quickly removing larger sections of mortar. Variable speed grinders are recommended for control.
- Mortar Rake: A specialized tool for removing mortar from joints.
- Stiff Wire Brush: For cleaning loose debris and mortar residue.
- Vacuum Cleaner (with HEPA filter): To control dust and remove debris.
- Muriatic Acid (Hydrochloric Acid) or Commercial Brick Cleaner: For removing stubborn stains and residue (use with extreme caution and proper PPE). Always dilute according to manufacturer’s instructions.
- Neutralizing Agent (Baking Soda and Water): To neutralize acid after cleaning.
- Water and Buckets: For rinsing and cleaning.
- Soft Bristle Brush: For applying and scrubbing with cleaning solutions.
- Grout Removal Tool: Optional, for very thin mortar joints.
The Mortar Removal Process: Step-by-Step
Removing mortar can be a dusty and time-consuming task. Following these steps will help you achieve the best results:
- Preparation: Put on your safety glasses, dust mask, and gloves. Work in a well-ventilated area. Cover surrounding surfaces to protect them from dust and debris.
- Mechanical Removal (Chisel Method): Using a brick hammer and chisel, carefully chip away at the mortar. Angle the chisel slightly away from the brick to avoid damaging it. Work slowly and methodically.
- Mechanical Removal (Grinder Method): If using an angle grinder, equip it with a diamond blade suitable for mortar removal. Gently grind away the mortar, being careful not to gouge the bricks. Use short, controlled passes.
- Mortar Rake: Use a mortar rake to further clean out the joints, especially after using a grinder.
- Cleaning: Use a stiff wire brush to remove loose debris and mortar residue.
- Vacuuming: Vacuum the bricks and surrounding area to remove dust and debris.
- Chemical Cleaning (Optional): If necessary, use a muriatic acid solution (diluted!) or a commercial brick cleaner to remove stubborn stains. Always test the solution on an inconspicuous area first. Follow the manufacturer’s instructions carefully.
- Neutralization (If Using Acid): After cleaning with acid, neutralize the surface with a baking soda and water solution.
- Rinsing: Thoroughly rinse the bricks with clean water.
- Drying: Allow the bricks to dry completely before using them.
Common Mistakes to Avoid
Avoiding these common mistakes can save you time, money, and frustration:
- Using Excessive Force: Using too much force with a chisel or grinder can damage the bricks.
- Ignoring Safety Precautions: Failing to wear safety glasses, a dust mask, and gloves can lead to injury and respiratory problems.
- Using Undiluted Acid: Using undiluted muriatic acid can damage the bricks and pose a serious health hazard. Always dilute according to the manufacturer’s instructions.
- Not Testing Cleaning Solutions: Failing to test cleaning solutions on an inconspicuous area can result in discoloration or damage to the bricks.
- Rushing the Process: Rushing the process can lead to sloppy work and damaged bricks. Take your time and be patient.
- Not Considering the Type of Mortar: Different types of mortar (e.g., lime mortar vs. cement mortar) require different removal techniques. Research the type of mortar before starting.
Comparing Removal Methods
| Method | Pros | Cons | Best For |
|---|---|---|---|
| Chisel & Hammer | Precise, minimizes risk of damaging bricks, good for small areas | Time-consuming, requires manual effort | Small projects, delicate bricks, removing mortar close to soft brick |
| Angle Grinder | Fast, efficient for large areas | Can damage bricks if not used carefully, produces a lot of dust | Large projects, hard mortar, bricks that can handle the abrasion |
| Mortar Rake | Effective for raking out joints, less aggressive than grinder | Can be tiring for large areas, less effective on very hard mortar | Prepping joints for repointing, removing loose mortar |
Frequently Asked Questions (FAQs)
What type of safety equipment is absolutely necessary for removing mortar?
Safety glasses are absolutely essential to protect your eyes from flying debris. A dust mask or respirator is equally important to prevent inhaling harmful dust particles. Gloves are also highly recommended to protect your hands.
Can I use a power drill to remove mortar?
Yes, you can use a power drill with a specialized mortar removal attachment, often called a mortar rake drill bit. However, exercise caution as it can be aggressive and potentially damage the bricks if used incorrectly.
How can I tell what type of mortar I am dealing with?
Determining the type of mortar can be tricky. Lime mortar is generally softer and crumbles more easily than cement mortar. You can also look for visual clues: lime mortar often has a lighter color and a more porous texture. A small acid test (diluted muriatic acid) can also help, as lime mortar will react more strongly.
What’s the best way to minimize dust when removing mortar?
Use a vacuum cleaner with a HEPA filter to collect dust as you work. You can also lightly mist the area with water to dampen the mortar and reduce dust generation, but be careful not to over-saturate the bricks.
How do I prevent damaging the bricks while removing mortar?
The key is to work slowly and carefully. Avoid using excessive force, and angle your chisel or grinder away from the brick. Practice on a less visible area first to get a feel for the process.
Is it okay to use muriatic acid on all types of bricks?
No, muriatic acid should be used with extreme caution, and it’s not suitable for all types of bricks. Always test on an inconspicuous area first. Some bricks, particularly soft or porous ones, can be damaged by acid. Consider using a commercial brick cleaner as a safer alternative.
How long should I let the bricks dry after cleaning?
Allow the bricks to dry completely before using them, which can take several hours to a day or more, depending on the weather conditions and the porosity of the bricks.
What do I do if the mortar is extremely hard and difficult to remove?
For extremely hard mortar, you may need to use a more aggressive grinding technique. Consider using a diamond blade specifically designed for hard mortar. You can also try using a mortar softening solution to help break down the mortar.
Can I reuse the old mortar as a landscaping material?
No, old mortar should not be reused as a landscaping material. It may contain harmful substances, and it’s unlikely to have the structural integrity needed for landscaping applications.
What is repointing, and why is it important after removing old mortar?
Repointing is the process of replacing the mortar in the joints of brickwork. It’s crucial after removing old mortar to maintain the structural integrity of the wall or structure and prevent water damage.
How do I choose the right type of mortar for repointing?
Choosing the right mortar for repointing is crucial for long-term durability. Match the type of mortar used in the original construction as closely as possible. Using a mortar that is too hard can damage the original bricks. Consult with a masonry professional for advice.
What are some signs that I should hire a professional to remove the mortar?
If you’re dealing with a large or complex project, if you’re uncomfortable working with power tools, or if you’re concerned about potentially damaging the bricks, it’s best to hire a professional. Also, older buildings may contain lead-based materials requiring special handling by a licensed professional.