
Repointing brickwork with lime mortar is an essential maintenance task that helps to preserve the integrity and appearance of your brick structures. Over time, the mortar between bricks can deteriorate due to exposure to the elements, wear, and age. Repointing not only strengthens the structure but also enhances its aesthetic appeal. This guide will walk you through the process of repointing brickwork with lime mortar, providing you with all the essential steps, tools, and tips for a successful project.
Why Use Lime Mortar for Repointing?
Lime mortar has been used for centuries in the construction of buildings and is still the preferred choice for repointing newtownabbey traditional brickwork. Unlike modern cement-based mortars, lime mortar is breathable and flexible, allowing moisture to escape from the walls without causing damage to the bricks. This is particularly important for historic buildings, where the wrong type of mortar can trap moisture inside the structure and cause long-term damage.
Some advantages of using lime mortar include:
- Breathability: Lime mortar allows moisture to evaporate from the structure, reducing the risk of damp issues.
- Flexibility: Lime mortar is more flexible than cement, allowing it to expand and contract with temperature changes without cracking.
- Aesthetic appeal: Lime mortar gives a natural, traditional finish that is ideal for historic buildings and properties that seek to retain their period charm.
Tools and Materials Needed for Repointing with Lime Mortar
Before starting the repointing process, gather the following tools and materials:
Tools:
- Pointing Trowel: A small, pointed trowel for applying and shaping the mortar in the joints.
- Masonry Brush: To clean the brickwork before repointing.
- Hammer and Chisel: Used to remove old mortar from between the bricks.
- Mortar Mixers or Bucket: For mixing the lime mortar.
- Water Spray Bottle: To dampen the brickwork before repointing.
- Safety Gear: Gloves, goggles, and a dust mask to protect from dust and debris.
Materials:
- Lime Mortar: Choose a premixed lime mortar or mix your own using lime putty, sharp sand, and water.
- Water: To moisten the bricks before applying new mortar and to adjust the mortar consistency.
Step-by-Step Guide on How to Repoint Brickwork with Lime Mortar
1. Assess the Condition of the Brickwork
Before beginning any work, inspect the brickwork to determine the extent of the damage. Look for cracks, gaps, or crumbling mortar that need attention. If the damage is extensive, you may need to remove more mortar or replace any damaged bricks before proceeding.
2. Remove Old Mortar
The first step in repointing is to remove the old, damaged mortar. This is typically done using a hammer and chisel. Carefully tap the chisel into the mortar joints, taking care not to damage the bricks. It’s essential to remove the mortar to a depth of at least 1-2 cm to ensure the new mortar bonds properly with the bricks.
Be mindful not to strike the bricks directly, as this can cause them to crack. Instead, focus on the mortar, working gradually to avoid damaging the surrounding brickwork. A masonry brush can be used to clean away any loose debris once the mortar has been removed.
3. Clean the Brickwork
After removing the old mortar, thoroughly clean the brick surfaces. Use a wire brush or masonry brush to remove any dirt, dust, and remaining mortar particles. You can also use a water spray to help remove any stubborn debris.
Cleaning the surface ensures that the new mortar will adhere properly and provides a clean, smooth base for the repointing process. This step is particularly important if you’re working with historic brickwork, where dirt and grime may have accumulated over the years.
4. Wet the Brickwork
Before applying the new lime mortar, it’s essential to dampen the brickwork slightly. This will prevent the dry bricks from absorbing too much moisture from the mortar, which can weaken the bond. Use a water spray bottle to lightly dampen the brick surfaces, but avoid soaking them. The bricks should be moist but not wet.
5. Mix the Lime Mortar
Lime mortar can be bought pre-mixed or mixed on-site. If you’re mixing your own, combine lime putty, sharp sand, and water to create the correct consistency. The mixture should be smooth and workable but not too runny.
A general recipe for lime mortar is:
- 1 part lime putty
- 3 parts sharp sand
- Enough water to create a workable consistency
If you’re using a pre-mixed product, follow the manufacturer’s instructions for mixing and preparation.
6. Apply the Mortar
Now you’re ready to start repointing! Use a pointing trowel to apply the lime mortar into the gaps between the bricks. Start at the top of the wall and work your way down to prevent mortar from falling onto freshly applied sections.
When applying the mortar, press it firmly into the joints to ensure there are no air pockets, and fill each joint completely. Once the mortar is in place, use the trowel to smooth the surface and shape the mortar to match the existing joints. If necessary, use a jointing tool to create a clean, uniform finish.
7. Strike the Joints
After the mortar has been applied and shaped, it’s time to finish the joints. You can achieve a neat finish by striking the joints with a pointing tool or a steel rod to create a slightly recessed or concave profile. This helps to ensure the repointed wall is both functional and aesthetically pleasing.
8. Allow the Mortar to Set
Once the mortar is applied, leave it to set for at least 24-48 hours. During this time, the mortar will harden and bond with the bricks. It’s essential to avoid disturbing the wall during this process.
If the weather is particularly hot or dry, you may need to dampen the mortar slightly during the curing process to prevent it from drying too quickly and cracking.
9. Clean Up and Final Touches
After the mortar has fully set, use a soft brush to remove any excess mortar or smears from the surface of the bricks. Avoid using harsh scrubbing, as this can damage the finish of the brickwork. If necessary, lightly dampen the surface to remove stubborn marks.
Inspect the wall for any areas that may need touching up or additional mortar. Address any minor imperfections before considering the project complete.
Tips for Successful Repointing
- Work in manageable sections: Focus on small sections at a time to ensure that the mortar doesn’t dry out before you finish.
- Use the right mortar: Ensure that the lime mortar you’re using is appropriate for the age and type of brickwork you’re working with.
- Be patient: Repointing takes time, so don’t rush the process. Take care with each step to ensure a professional finish.
- Check the weather: Repointing is best done in mild weather. Avoid working during heavy rain or freezing temperatures, as this can affect the mortar’s ability to set properly.
Conclusion
Repointing brickwork with lime mortar is a rewarding and essential task for maintaining the structural integrity and aesthetic appeal of brick buildings. With the right tools, materials, and techniques, you can restore your brickwork to its former glory and help preserve it for years to come. Whether you’re working on a historic building or simply updating your home, using lime mortar ensures that your brickwork remains breathable, flexible, and attractive.