How To Repoint Brick and Stone Structures

Repointing, also known as tuck pointing, is the process of removing the existing mortar from between bricks or stones and replacing it with freshly mixed mortar. In this guide, we will go over everything you need to know about how to examine mortar joints and ensure that repointing is necessary. We will also go over how to tuck point properly, including the correct tools and methods used.

The Signs: Knowing When It’s Time To Repoint

Mortar, like anything else, has a certain shelf life. Environmental factors such as rain, moisture, plant growth, tremors, freezing temperatures, heat waves, etc., all play a role in destabilizing mortar. If mortar is recessed or no longer present in certain areas of the brick or stonework, it’s likely that the remainder of the masonry structure is also compromised. Separations or cracks between masonry units and mortar is also a clear indicator that repointing is required. Mortar joints should be fully attached and solid between any masonry structure. Decrepit mortar doesn’t always make itself obvious. Sometimes, the surface of a mortar joint may appear stable but upon subjecting it to a blunt tool such as a flathead screwdriver, you’ll find that it’s soft and flaking, indicating that there is a moisture issue. As with anything else, it’s best to implement preventative measures and catch failing mortar before it leads to greater issues down the road.

The Repointing Process:

Recessing and cleaning the mortar joints:

1. The first step is to recess the existing mortar by at least an inch (1-1/2” is usually best depending on the type of masonry materials involved), followed by a thorough cleaning of the joints with direct air pressure. Here at Lennox Masonry, we utilize a variety of means for each specific application when it comes to recessing mortar joints. For chimneys and brick walls we have had great success in using tuck pointing grinders with vacuum hose attachments to minimize dust. In regard to stone walls, we have found that air powered chisels work best on stonework due to the randomness of the mortar joints. And sometimes we’ll just use a good old fashioned hammer and chisel if it’s a small repair project.

2. Moisten the brick or stone as well as the cleaned out mortar joints with a spray bottle, sponge, or a hose on a shower-type setting. You don’t want to overly saturate the masonry but you also don’t want it too dry either. In essence, you want to ensure that the mortar will grab and bond with the masonry units and that the stone or brick doesn’t suck too much moisture out of the mortar too quickly. A delicate balance is needed.

3. Determining which type of mortar best suits your project depends on a variety of factors. Such as: the type of brick or stone you’re working with, whether or not it is a load bearing wall, as well as the masonry structures exposure to the elements. For a full breakdown of the right types of mortar for the right type of masonry project, read our blog post:Masonry & Mortar: A Guide To Different Types Of Mortar And Their Uses

4. Once you have established which mortar you will be utilizing, it’s time to gather the necessary tools for the job. There are several different ways to place the mortar into the joints and it mainly comes down to preference. You can either place the mortar on a Hawk or a pointed trowel and use the correct sized jointer for your application to press it in, or fill a grout bag full of mortar and squeeze it in. Both have their pros and cons. The grout bag requires some practice in regard to squeezing out the mortar properly so that there aren’t any pockets of air left behind. It can also be hard on the wrists and hands but it is incredibly efficient at getting mortar into place quickly with a practiced hand. It also excels at filling vertical joints. However, if your project requires a stiffer, drier mortar, or a coarser sand, a grout bag will likely be an inefficient tool for your masonry project, as it becomes quite cumbersome to squeeze out mortar when it isn’t wet enough or doesn’t contain fine sand. The Hawk or pointed trowel method is great at ensuring that the mortar joints are fully packed. While it will take longer to fill in the mortar joints and will also take some patience for those who aren’t skilled in repointing vertical mortar joints, this is the go-to method when working with mortars which contain coarse sand. Whichever method you choose, be sure to allow the fresh mortar to overhang the brick or stone by about an 1/8th of an inch. The reason being, when you proceed with jointing and pressing the mortar in place, you’ll want some extra mortar to pack in and create a thoroughly sealed joint with.

5. The next step is to allow the mortar to dry until it feels somewhat stiff. It should still contain its original colour (if it starts to look white or light grey it’s dried for too long) and feel hard to the touch. The type of jointer used to rake back and seal the joint will depend on the style of finish you’re going for. No matter the preferred finish, be sure to keep the joint consistent when it comes to its overhang, depth or recession. Uniformity is the key if you want to ensure the masonry structure will be aesthetically pleasing. Like anything else, creating even mortar joints takes a degree of practice. Applying consistent pressure and movement over the distance of a mortar joint usually takes years to master. Jointing is the final touch to a masonry structure. It can either make it or break it, so take your time and proceed with patience.

6. The final step is to allow your mortar joints to dry until the surface is barely impressionable and then lightly brush the joints with a painters brush. Brushing is done in an effort to remove any tool marks as well as press the mortar into the stone or brick to create a tight seal. This makes for a smooth and consistent feel to the mortar. Once all of the mortar joints are brushed, use a dampened sponge of choice to gently wipe the face of the stone or brick clean from any mortar residue. If there are stubborn stains that won’t come off or you've left chunks of mortar on the face for too long, you can use a stiff bristled brush to help remove them. A cleaning solution may also be required but allow the mortar joints to cure for sometime prior to cleaning the masonry structure with a solution or a hose.

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Lennox Masonry of Victoria, BC has been proudly serving both Vancouver Island and the Gulf Islands for over a decade. We are small group of skilled masons with a great deal of passion towards our trade and for improving the communities we live and work in. We extend our gratitude to the lək̓ʷəŋən people for allowing us to share and work on this corner of the garden with them. We are thankful for the residents and businesses of Victoria, BC for supporting us in our endeavors!

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