How to Repoint Historic Brick: A Step-by-Step Guide

Frederick M Hueston StoneForensics.com

Repointing historic brick is a crucial preservation task that helps maintain the structural integrity and aesthetic appeal of older buildings. Over time, weather and environmental factors can cause the mortar between the bricks to deteriorate. Repointing involves removing and replacing the deteriorated mortar, which not only restores the brickwork but also ensures the building’s longevity. In this step-by-step guide, we’ll walk you through the process of repointing historic brickwork.

Materials You’ll Need:

Safety Gear:

Safety goggles

Dust mask

Work gloves

Ear protection

Tools:

Pointing trowel

Brick jointer

Mortar hawk

Masonry brush

Cold chisel and hammer

Wire brush

Bucket

Water hose with spray nozzle

Mortar mix (matching the original)

Mortar jointer

Preparation:

1. Safety First: Put on your safety gear to protect yourself from dust, debris, and sharp tools.
2. Assess the Mortar: Examine the existing mortar to determine its type and condition. Match the new mortar to the old in terms of type, color, and texture.
3. Clean the Area: Remove loose mortar and debris from the joints using a wire brush and a masonry brush. Be gentle to avoid damaging the bricks.
4. Soak the Bricks: Spray the brickwork with water to saturate it, preventing the bricks from drawing moisture out of the new mortar too quickly.

Repointing Process:

Mixing the Mortar:

Follow the manufacturer’s instructions for mixing the mortar mix. Typically, you’ll need to combine dry mortar mix with water until you achieve a workable consistency.

Removing Old Mortar:

Use a cold chisel and hammer to carefully remove the old mortar from the joints. Be cautious not to damage the bricks.

Use a wire brush to clean out any remaining debris from the joints.

Preparing the Joints:

Dampen the cleaned joints with a mist of water. This will improve adhesion between the new mortar and the bricks.

Applying the New Mortar:

Load your mortar hawk with the prepared mortar mix.

Use a pointing trowel to fill the joints with the new mortar. Press it in firmly, making sure there are no voids.

Tool the mortar joints with a mortar jointer or brick jointer to achieve the desired finish. Match the style of the original jointing.

Finishing Touches:

Clean any excess mortar from the brick faces while it’s still wet using a damp cloth or sponge.

Curing:

Protect the newly repointed brickwork from direct sunlight and excessive drying by covering it with damp burlap or plastic sheeting.

Keep the repointed area damp for several days to ensure proper curing.

Cleaning Up:

Clean your tools and dispose of waste materials properly.

Repointing historic brick is a skillful task that requires attention to detail and patience. By following this step-by-step guide and taking the time to match the new mortar to the old, you can help preserve the beauty and structural integrity of historic brick buildings for generations to come. Always prioritize safety and consult with a professional if you’re unsure about any step in the process.