Stone walls have been a popular building material for centuries, and they remain a popular choice for homeowners today. However, over time, the mortar between the stones can deteriorate and crumble, leading to structural issues and a less attractive appearance.
Repointing, or replacing the deteriorating mortar, is a necessary maintenance task for stone walls.
While it may seem daunting to repoint a stone wall, it can be done by following a few basic steps. In this article, we will explore how to repoint a stone wall, from preparing the surface to choosing the right mortar mix and tools. With the right techniques and materials, you can restore your stone wall to its former beauty and strength.
What Do You Use to Repoint a Stone Wall?
Repointing a stone wall typically involves removing existing mortar, cleaning out any cracks or gaps, and replacing with new mortar.
It is important to use the right type of mortar for repointing your stone wall because it will affect the durability and strength of your wall over time.
When selecting a mortar, consider its ability to resist water penetration and its ability to provide a strong bond between the stones and the mortar. In addition, consider whether the mortar will match the existing color of your wall or if you would like to use a different color to update the look of your wall
To begin repointing a stone wall, start by using a hammer and chisel to remove existing mortar. Use light pressure and a chisel with a wide blade to keep from damaging the stones. Once you have removed all of the old mortar, use a vacuum cleaner to remove any loose particles.
Next, mix your new mortar according to the instructions on the package. Ensure that it is well mixed before applying it to the wall. Using a pointing trowel, work the mortar into each joint between stones and then smooth it out using either a pointed or flat-edged trowel.
10 Methods How to Repoint a Stone Wall
1. Preparing the Surface
Before repointing a stone wall, it is important to prepare the surface properly. First, clean the wall thoroughly to remove any dirt, debris, or loose mortar. Use a wire brush or a pressure washer to remove any stubborn debris.
Once the surface is clean, allow it to dry completely before proceeding. If the mortar is crumbling or powdery, use a chisel and hammer to chip away any existing mortar. While chiseling, ensure you’re not damaging the stones below the mortar.
2. Removing Old Mortar
The next step is to remove the old mortar. Use a hammer and chisel or a mortar removal tool to carefully chip away the old mortar from between the stones. Be sure to remove all loose or deteriorating mortar, as leaving it in place can cause further damage to the wall.
Be careful not to chip away too much mortar, as you may damage the stones. To prevent this, take your time and be sure to get in between all the joints. However, if the stones are too close together to use a tool, you can try using either a stiff brush or a wire brush to remove any loose dirt and debris.
3. Choosing the Right Mortar Mix
Choosing the right mortar mix is crucial for the success of the repointing process. Select a mortar mix that matches the color, texture, and strength of the original mortar. Use a high-quality, pre-mixed mortar that is specifically designed for repointing stone walls.
This will ensure that the mortar withstands weather conditions and will last for many years. Make sure to mix the mortar according to the manufacturer’s instructions and add just enough water so that it is slightly wet but not soupy.
Once your mortar is thoroughly mixed, brush away any loose debris from the joints in the stone wall. This will help ensure that your new mortar bonds securely to the stone and doesn’t wash away when exposed to water or other elements.
4. Mixing the Mortar
Once you have chosen the right mortar mix, it is time to mix it. Follow the manufacturer’s instructions carefully, adding water to the mix gradually until you achieve the desired consistency. Mix only as much mortar as you can use in 30 minutes to ensure that it does not dry out before you can use it.
If you need more mortar, you can mix a new batch later. While you are mixing the mortar, make sure to wear gloves and a mask to protect yourself from any airborne particles. If there are children or pets in the area, make sure they stay away from the mixing and repointing area.
5. Applying the Mortar
Using a pointing trowel, carefully apply the mortar to the joints between the stones. Be sure to fill the joints completely, pushing the mortar into any gaps or voids.
Use a striking tool or a jointing tool to smooth the mortar and create a uniform appearance. Take care not to apply too much mortar, as this can cause it to bulge out and make the wall look uneven.
Make sure the jointing tool is held perpendicular to the wall to ensure a consistent line. Although the mortar can take up to 24 hours to dry, it is important not to disturb the joints until they are fully cured. When the mortar is completely dry, the repointed stone wall should look as good as new.
6. Finishing the Joints
Once the mortar has been applied, use a pointing tool to finish the joints. This involves removing any excess mortar and creating a smooth, even finish. Be sure to match the style and appearance of the original joints as closely as possible.
You may also need to use a jointing tool in order to create a curved or angled finish. When you are done, allow the mortar to dry thoroughly before continuing.
You can use a damp cloth to remove any excess mortar from the surface of the stone. Your wall should now be properly repointed and ready to be enjoyed. Congratulations! Have fun admiring your handiwork.
7. Protecting the Wall
To protect the newly repointed wall, cover it with a damp cloth or tarp and mist it with water regularly for the first 24 hours. This helps to prevent the mortar from drying out too quickly and cracking. After the first 24 hours, allow the wall to dry slowly as it cures.
To finish the project, use a stiff brush to clean off any excess mortar and make sure to seal the repointed areas with a water-repellent sealant. This will ensure that your stone wall remains in excellent condition for many years to come. Once you have finished this step, your newly repointed stone wall is ready to be admired.
8. Cleaning Up
Once the repointing process is complete, clean up the work area thoroughly. Remove any excess mortar from the surface of the stones, and clean your tools and equipment.
If you’re using hydraulic lime mortar, it is important to clean up any spills that have occurred as soon as possible, since it can be damaging to the surrounding environment.
Take the time to double-check your work and make sure all of the new pointing looks uniform and consistent. Once you’ve finished cleaning up, admire your handiwork and bask in the satisfaction that comes with a job well done!
9. Checking for Proper Cure
Allow the mortar to cure for at least 24 to 48 hours before subjecting it to any stress or pressure. Check the joints to ensure that they are firm and stable before proceeding. If not, wait for additional time for the mortar to cure and set.
Once the mortar is cured, use a bush hammer or other tool to lightly strike the joints until they are flush with the wall surface, then brush away any debris that may have collected on top of them.
This will ensure a neat finish. Next, use a sealer to protect the mortar from water damage and weathering. Finally, inspect your work to make sure you have achieved a uniform, aesthetically pleasing result. With proper care and maintenance, your newly repointed stone wall will be strong and lasting for many years to come.
10. Maintaining the Wall
To maintain the newly repointed wall, regularly inspect it for any signs of damage or deterioration. Clean the wall regularly to prevent the buildup of dirt and debris, and address any issues promptly to prevent further damage. Additionally, periodically check the mortar joints to ensure that they remain in good condition.
If any cracking or crumbling is observed, repointing may need to be done again. Try to use the same type of mortar that was used for the original repointing job.
This will help ensure a good bond between the old and new material. Finally, always use a hard-bristle brush when cleaning off the mortar to prevent scratching or chipping of the wall surface. With proper care and maintenance, the newly repointed wall should last for many years.
Some Common Mistakes to Avoid When Repairing a Stone Wall
1. Not Accounting for the Weight of the Stones:
When repointing a stone wall, it is essential to take into account the weight of the stones chosen for the repair. If the stones are too large and heavy, it can cause a structural imbalance that may shift or damage the wall.
2. Not Using Proper Mortar:
Using an incorrect type of mortar when repointing a stone wall can also cause structural issues. The mortar should be designed specifically for use on stone walls and should match the existing mortar used in the wall.
3. Not Cleaning Existing Mortar:
Prior to repairing a stone wall, it is important to clean any existing mortar from the stones. If this step is skipped, it can cause issues with adhesion when applying new mortar.
4. Not Allowing Enough Time for Curing:
When repairing a stone wall, it is essential to allow adequate time for curing between each layer of mortar applied. Skipping this step or rushing through the process can lead to weak spots in the repair job.
5. Not Protecting Wall Surfaces During Repointing:
Protecting surfaces around a stone wall during repointing is essential to prevent damage due to splatter or errant mortar. Covering the area with tarps and using a shop vacuum to clean up excess material can help ensure a successful repair job.
By avoiding these common mistakes when repointing a stone wall, you can ensure that your repair job is successful and will last for many years to come. With a little bit of preparation care, you can restore yours to its former glory.
What Type of Mortar Is Best for Stone Walls?
When repointing a stone wall, it’s important to use the right type of mortar. Mortar must be flexible enough to accommodate any movement in the wall and also strong enough to secure the stones in place. The best options include masonry cement or lime-based mortar.
Masonry cement is a pre-mixed blend of Portland cement and specialized sand. It creates a strong bond between masonry surfaces, as well as offering flexibility and durability.
Lime-based mortar is a combination of lime and sand, which helps to stabilize the wall while also allowing moisture to escape. This type of mortar is more porous than masonry cement, so it’s best for older walls or those located in wet climates.
Conclusion
Repointing a stone wall is not a simple task and should be done with caution. Taking the time to properly plan and prepare before beginning can help ensure that you get the best results while also helping to protect against any potential dangers or errors.
It’s also important to remember that even under ideal conditions, repointing a stone wall is often a lengthy process that requires patience and attention to detail. With dedication and carefulness, however, you can repoint your stone wall effectively and enjoy it for many years to come.
If you’re ready to tackle this project yourself, please check out our How to Repoint a Stone Wall guide for step-by-step instructions on achieving beautiful results. Good luck!