Repointing with lime mortar

Repointing with lime mortar is so beneficial. But why? And what is repointing in the construction industry? Find out the advantages and more, below.

Repointing with lime mortar makes building work tasks a lot easier, and neater. But why use lime mortar when builders are so used to repointing with concrete? Find out this and more, below.

What is lime mortar?

Lime mortar is a great building and brick-laying material that construction workers can use with ease. But what is it?

Lime mortar is made up of hydraulic or non-hydraulic lime aggregate (such as grit or sand), alongside water. These are the ingredients needed to make lime mortar yourself, or using a cement mixer.

Lime mortar would typically be used when a building needs repointing, as a lot of cement-based mortars are too tough. This then causes masonry to be damaged, which no one wants.

So, repairing buildings by repointing them with lime mortar is much better. And it makes this building job a lot easier.

What does repointing with lime mortar mean?

In masonry, repointing is the process of restoring or repairing the joints between bricks or stones in a wall or chimney.

Weathering, water damage, and the ageing process of the materials can all cause mortar joints to deteriorate over time.

Repointing strengthens the structure of a building. It also enhances its look by replacing or sprucing up the mortar in these joints.

Repointing with lime mortar: What to do

Repointing brickwork is an essential house maintenance job. And one that should always be carried out by a professional.

And if inappropriate materials are used, it can lead to serious issues with damp. And nobody wants that!

But how does this happen? Well, because mortar is a primary defence for water ingress. This means brickwork that has been jointed using lime mortar needs to be pointed using the same material.

This is because old properties naturally have some moisture penetrating the masonry, which can evaporate through the lime mortar. Therefore, if you use a cement mix, water won’t be able to move freely between the joints and the wall will become damp.

Why use lime mortar for repointing?

Using lime mortar for repointing has many advantages. But what are they?

The benefits of lime mortar when repointing

• Lime mortar is better for waterproofing

• More traditional concrete takes on more moisture. So, it makes more sense to use lime mortar for repointing

• It’s great for the environment. As it produces less carbon dioxide than ordinary cement

• It’s more attractive than standard concrete. This makes repointing a lot cleaner looking

• Lime mortar has a low modulus of elasticity. So, it’s very flexible by allowing for movement and thermal expansion

• Its structure means it doesn’t run the risk of being affected by frost and salt damage

• Dust is removed from the joints during cleaning

The repointing process using lime mortar

The following steps are involved in the repointing process:

1. Removal of old mortar

Removing old mortar comes first. This typically involves using equipment like chisels or grinders.

Then, the crumbled or broken mortar is slowly and gently removed from the joints.

It’s crucial that you take extra care, and don’t break any of the stones or bricks in this process.

2. Cleaning the joints

Cleaning the joints before repointing with lime mortar guarantees a solid connection with the new mortar.

The joints are then cleared of dust and debris. This is to remove any old/leftover pieces of mortar left behind.

3. Mix fresh lime mortar

Next, a fresh lime mortar mix needs to be made to guarantee a smooth and appealing aesthetic.

This is done to resemble the original mortar's three components:

4. Start repointing the lime mortar

Use a trowel or other similar tools to clean the building’s joints. This creates, and guarantees, a strong adhesion between the mortar and the masonry components.

• Colour

• Composition

• Texture

And extra care will need to be taken to fill the whole connection.

5. Tooling and finishing

Last comes tooling and finishing. After repointing the lime mortar, it needs to be tooled to resemble the original joints.

This helps to preserve the historical/architectural integrity of the structure being worked on.

Now you’re all set. But if you want to know the costs of repointing using lime mortar, view our repointing cost guide.