What is mortar?
Q: We have moved into a new house and recently found several holes in the mortar joints in the brick wall which appear to be caused by a drill. We have found several types of mortar, but I’m still not sure what the best option is to fix these holes. What exactly is mortar and is there a difference between the different types? Can we use any type to fix the brick wall?
A: Repairing the brick exterior of the house can range from simply patching a few holes to removing and replacing entire strips of crumbling mortar. In these situations, mortar is the key component needed to complete the repair. Simply put, mortar is a common bonding agent used between masonry materials, such as brick or concrete block.
Mortar is made from a mixture of cement, fine sand, water and lime, although it can also include latex, polymer additives and cellulose derivatives, depending on the type. Mixing changes the composition, allowing the mortar to be used for specific purposes or with specific materials.
There are four common types of mortar, including S, N, M and O types. They are differentiated on the basis of compressive strength, flexibility and bonding properties. Typical repairs to a residential property require Type S or Type N mortar, although Type O is sufficient for non-loadbearing walls, such as a partition wall inside a building.
Mortar is a mixture of cement with fine sand, water and lime.
Cement is created by mixing limestone, clay, shells and silica sand, crushing the mixture and heating it to around 2,700 degrees Fahrenheit. This powdered product is then mixed with water to create a hard and durable cement. However, when cement is combined with fine sand, water and lime, it produces a sticky mortar paste which acts as a bonding agent or adhesive.
By mixing fine sand into the cement, nothing really happens because the sand would separate from the cement mixture. Lime solves this problem by binding the sand to the cement so that the new composition increases the flexibility and compressive strength of the concrete, allowing the mixture to take on a new shape. Adding water then activates the mixed components, creating a thick, pliable mortar paste that can be applied for a few hours before it hardens.
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Mortar is a bonding agent used between bricks, concrete blocks and other masonry materials.
When water is added to the cement, it creates a malleable combination that dries in a few hours and completely hardens into a strong, rigid piece of cement in about 24 to 72 hours, depending on the product. However, the stiffness of cement makes it a poor option for absorbing the movement of a building, which should be able to flex and move with high winds, precipitation, and changing temperatures.
The mortar incorporates fine sand and lime into the mixture, which increases flexibility, adhesion and compressive strength, allowing the mortar to act as a bonding agent between bricks. This flexible bond helps building materials absorb the natural movement of the building without cracking or breaking. It can be used between bricks, concrete blocks, stone and other masonry materials, or it can be mixed with a latex or polymer additive for tile installation.
Thin-set mortar is used to install the tiles.
When replacing flooring in the bathroom, repairing the wall in the shower stall, or installing a backsplash in the kitchen, a special type of mortar is commonly used to install the tiles. Thin-setting mortar is made of cement, fine sand, and water, but it also contains a cellulose derivative which acts as a water-retaining agent to increase flexibility and adhesion.
This formula adheres tightly to the back and sides of the tile to prevent displacement, gaps and water damage. Some thin-set mortars will incorporate a latex or polymer additive which increases the bond strength of the mixture. Due to this high quality of adhesive, thin-set mortar can be referred to as thin-set adhesive, so be sure to read the product information to make sure you choose the right mortar for your project.
Powdered or premixed mortar.
Browse online stores or visit your local home improvement store to find various mortar products, including powdered and premixed mortar.
Powdered mortar is a good option for professional masons who prefer to mix mortar with cement using a custom scale that can produce the ideal results for every project. However, without experience, powder mortar can be difficult to use. If the mixture is not properly balanced, the mortar may be too watery to adhere to the brick or it may crack and crumble after curing.
Pre-mixed mortar is the best choice for DIY enthusiasts who want to do some repairs outside the home. These products contain all of the dry ingredients premixed in a bag so all you need to do is add water for the perfect balance to patch holes or replace old damaged mortar.
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There are few types of mortar, including S, N, M, and O.
Mortar is available in four common types, including S type, N type, M type and O type. The four types are differentiated by the composition of the mortar, which affects compressive strength, flexibility and strength. binding properties.
- Type S mortar is most commonly used for residential projects. It is the second strongest of the four types with a force of around 1,800 pounds per square inch (psi). Due to its high tensile strength, it can withstand soil pressure and seismic loads, making it a good option for basement walls and foundations. It is made up of two parts of cement, one part of hydrated lime and nine parts of fine sand.
- Type N mortar is also routinely used for residential applications, although it is only recommended for use above ground as this mortar has a lower strength of only 750 psi. It is made of one part cement, one part lime and six parts fine sand, which gives it a high level of flexibility that can withstand weathering and extreme temperature variations.
- Type M mortar is generally not needed for residential repairs. This type of mortar has a nominal strength of 2500 psi and is commonly used in applications that involve extreme pressures or side loads, such as retaining walls. The mortar is composed of three parts of cement, one part of hydrated lime and 12 parts of fine sand.
- Type O mortar should only be used in non-loadbearing projects, such as a partition wall, decorative fireplace wall, or patio flooring, as this mortar has a low strength rating of only 350 psi. If it is too heavy, the mortar can crack, collapse and collapse, leaving the bricks unsupported. It is composed of one part of cement, two parts of hydrated lime and nine parts of fine sand.