Building a structure with the right mortar type enhances the strength and longevity. Different types of mortar exist, each with varying compressive strength, flexibility, and bonding properties. Each mortar has specified sand proportions, Portland cement, and hydrated lime applicable for various projects.
It doesn’t matter whether you go with Type S or Type N mortar. It is important to ensure their properties and functionalities meet your desired requirements. Type S mortar is fundamentally known for its increased strength and durability, it can be widely used in load-bearing foundations and walls. In contrast, Type N mortar is highly versatile and suitable for non-load-bearing walls and repairs.
To make the best choice, understand the key differences between both mortar mixes. In this article, we’ll explain them clearly:
Overview of Type S Mortar
Type S mortar is particularly designed for harsh weather conditions. It is recognised for its exceptional durability and strength. It is composed of ingredients in the ratio of one part lime, two parts cement, and nine parts sand.
Type S mortar is a common choice for masonry applications such as sewers, foundations, retaining walls, and manholes. It has an average compressive strength of around 12.41 N/mm², however, the mixes can yield a strength between 15.8 and 20.6 N/mm².
Overview of Type N Mortar
Type N mortar is the most commonly used mortar mix and possesses a compressive strength of around 5.17 N/mm². It is versatile and recommended for use on exterior and above-grade walls.
Type N mortar is composed of 1 part lime, 1 part Portland cement, and 6 parts sand, providing balanced strength and flexibility. It is a preferred choice for both interior and exterior load-bearing installations. Notably, it can achieve a strength between 10.3 and 16.5 N/mm² after 28 days.
Key Differences Between Type N and Type S Mortar
Type N and Type S mortars have different properties and are used for various purposes. The key differences between these mortars help you choose the right type. Herewith, both the components are differentiated in detail:
| Features | Type S Mortar | Type N Mortar |
| Composition | Type S mortar is composed of sand, Portland cement, water, along with Hydrated lime. | Type N Mortar contains water, Portland cement, lime, and sand. |
| Strength and Compression | It offers high-strength applicable to both below-grade and above-grade masonry units. | Type N mortar has a medium strength, suitable only for above-grade masonry units like block and brick. |
| Compressive Strength | Due to its excellent water-resistant property, Type S mortar is ideal for areas susceptible to moisture content and extreme weather conditions. | It contains a compressive strength around 5.17 N/mm², which is not suitable for structures requiring high strength and durability. |
| Water Resistance | Due to its extreme water resistant property, Type S mortar is ideal to areas susceptible to moisture content and extreme weather conditions. | Compared to Type S mortar, it has moderate water resistance. It makes them applicable only for above-grade applications. |
| Flexibility | Type S mortar is highly flexible, allowing it to withstand movement and cracking. | Type N Mortar has moderate water resistance and is suitable for only the above-grade applications. |
| Bonding Properties | It provides exceptional bonding properties, ensuring a strong and reliable bond between masonry units. | It has good bonding properties but less likely than Type S mortar. |
| Application | It can be used for a wide range of applications such as foundations, load-bearing walls and masonry units. | Type N mortar is primarily used for above-grade masonry applications, such as block walls and brick veneer. |
Advantages and Disadvantages of Type S Mortar
Advantages
Longevity: Type S mortar provides extreme longevity and can handle the pressure created from wind, seismic loads, and moisture. However, its resistance to freeze-thaw cycles will cause impacts to other materials.
Applicable for Marine Structures: Type S mortar has low permeability and is used widely in marine structures like piers, seawalls, and docks.
Masonry Applications: It is a popular choice for masonry applications where structural stability is paramount, such as laying bricks, stones, or blocks.
Disadvantages
Expensive: Due to its improved properties and higher strength, Type S mortar is more costly than Type N mortar.
Not Fit for Certain Applications: Type S mortar is highly versatile, which cannot be a suitable option for all kinds of masonry applications, especially in areas where strength and water resistance are not so required.
Advantages and Disadvantages of Type N Mortar
Advantages
Easy to Apply: Type N mortar is easy to apply and finish, and it doesn’t require any special skill sets or equipment to handle.
Low Price: From initial to end, the cost of materials and labour is typically low compared to Type S mortar.
Disadvantages
Limited Versatility: It is particularly designed for above-grade masonry applications, making it not suitable for areas where the strength and water resistance are important.
Lower Strength: Type N mortar is possessed with lower compressive strength, which makes them less suitable for load-bearing applications.
Factors to Remember When Choosing the Mortar
Choosing the mortar type is typically based on the project requirements. But here are the lists of factors that help you choose the appropriate one:
Load-bearing Requirements: If your structure involves load-bearing walls or foundations, then you need a mortar type with higher strength and durability. It helps withstand heavy pressure, movement, or vibration.
Weather Condition: When planning your construction in areas prone to harsh weather conditions, choose mortar with high water resistance. Then only the structure can survive without any cracking or critical damage.
Pricing: Budget is the primary concern of any construction project. Generally, Type N mortar is more affordable than Type S mortar. By considering your project needs and requirements, you can choose the best one within your budget.
Final Thoughts
In this article, you have seen the key differences between Type S and Type N Mortar. It makes you understand which mortar will be the best choice for your project needs, including cost considerations, the skill level of the labour, load-bearing capacity, and exposure to moisture. With careful consideration, we can ensure the success of every masonry project.