Tuckpointing is a mortar joint repair process in masonry construction, which involves the removal of deteriorated mortar joints from the masonry followed by replacement with a fresh mortar mix.
The mortar color used for tuckpointing must match the existing mortar to enhance the appearance. Tuckpointing is not only performed on old joints, but also for improper joints of new walls.
This article explains the basic procedure, mixing, and application of mortar for the tuckpointing process.
Preparations for Tuckpointing
Tuckpointing is usually performed by experienced masons and laborers. Before conducting the process, the existing problem of the masonry is assessed. This helps to determine whether the joints require reparation or replacement of mortar in failed joints.
The condition of mortar joints, the age of the building, and the type of mortar mix decide whether the complete structure requires cleaning or not. Normally, a power drill, chisel, or masonry cutting wheel is used to clean and cut the mortar joints for tuckpointing.
Mortar Mix for Tuckpointing
The masonry units spall out when tuckpointing is performed over old mortar works. The following procedure is conducted to perform good tuckpointing:
- Remove the old mortar using suitable tools. Usually a saw and a grinder are used for this purpose. Always check whether there is a need for power tools.
- If mechanical tools are employed, ensure not to damage the masonry units. For old masonry construction work, heavy vibration from these machines is undesirable.
- Perform the joint removal process by wearing proper personal protective equipment.
- Start removing the old mortar to a full depth of 3/8 inches to 1/2 inches. Continue this till a firm mortar mix is obtained.
- Never remove the mortar from the joint beyond the depth of 1/3 inch.
- After removing the mortar, clean the joint by brushing and rinsing with water or blowing air. This removes dust, debris, and fine particles.
- Select the mortar mix for the joints. Extreme shrinkage can be reduced by employing pre-hydrated mortar.
- The color of the new mortar can be matched with the existing mortar by adding additives.
- Mix all the ingredients of the mortar thoroughly. Add water and mix until the mortar forms a thick mix to form a ball. The mortar must not flow in any case.
- Allow the mix to set and hydrate for two hours. The workability can be increased by adding the required amount of water.
Applying Mortar for Tuckpointing
- Before applying mortar to the joints, dampen the tuckpointing joints. This helps to have a proper bond with the existing surface.
- Many tools and products are available for easy placement of mortar into the joints.
- Use the tip of the trowel to place the mortar paste into the joint. Fill the joints with mortar and scrape out the excess.
- When the mortar starts to harden, strike the joints using a joint strike tool. Perform the procedure starting from vertical joints and then horizontal joints.
- Place the mortar in 1/4-inch layers (maximum) to reduce the number of voids and air pockets.
Tuckpointing is one way of providing a waterproof mortar joint to the masonry structure. It matches with the existing appearance, giving a better finish to the interiors and the exteriors. Tuckpointing also helps to increase the life of the structure.
Tuckpointing is a mortar joint repair process in masonry construction. It is the process of removing the deteriorated mortar joints from the masonry and cutting them to a uniform depth and filing with a fresh mortar mix. Tuckpointing is not only performed on old joints, but also for improper joints of new walls.
Tuckpointing is one way of providing a waterproof mortar joint to the masonry structure. It matches with the existing appearance, giving a better finish to the interiors and the exteriors. Tuckpointing also helps to increase the life of the building structure.
A power drill, chisel, or masonry cutting wheel are used to clean and cut the mortar joint for tuckpointing. A saw and a grinder are also used to remove old mortar from the joints.