What are the disadvantages of lime in construction?

Author: Idella Kutch  |  Last update: Monday, September 11, 2023

Disadvantages. Non-hydraulic lime plaster sets slowly and is quite caustic while wet, with a pH of 12. Plasterers must take care to protect themselves or use mild acids as vinegar or lemon juice to neutralize chemical burn. When the plaster is dry, the pH falls to about 8.6.

What are the defects of lime in construction?

Deterioration processes can result in a range of defects including cracking, debonding, loss of strength and surface erosion. Lime mortars, plasters and renders are designed to be weaker than masonry units (i.e. stone or clay bricks) and are intended to decay in a sacrificial manner in order to protect these units.

Why don't we use lime instead of cement?

Generally, cement is used instead of lime due to its much faster set time. Having a faster set allows cement construction to be faster than building with lime. In the long run, buildings constructed with cement can be built quicker and more cheaply when compared to lime.

Why is lime plaster no longer commonly used?

There are a couple of reasons for this. Firstly, the process of applying the lime plaster takes longer and is more involved meaning higher labour costs, although most plasterers will still just charge a standard day rate. The second reason is that lime products tend to be more expensive to buy than cement.

Is lime better than concrete?

Lime mortar has better waterproofing

Traditional concrete only mixes were prone to taking on moisture from the atmosphere. This caused the mortar to expand and contract as it heated and cooled. Also the water in the mortar would be susceptible to freezing. All this would mean your mortar, over time, would crumble.

Advantages of using Lime instead of Cement in construction | Sandeep Sonigra | TEDxSIUHinjewadi

How long does lime mortar last?

Most bagged, hydrated lime has a shelf life of 12 months once kept dry and sealed. Once opened bags should be used straight away or resealed so as to be airtight. Some premixed lime mortars with additives may have a shorter shelf life. Lime putty will last indefinitely once kept underwater and airtight.

When did lime mortar stop being used?

Lime mortar has been used in construction since the time of the ancient Egyptians around 4,000 to 6,000 BC. It continued to be used until the 19th century, when the introduction of Portland cement led to the emergence of cement mortars, which were faster setting and had a higher compressive and flexural strength.

Can lime plaster grow mold?

Lime plaster is well known for its moisture buffering capabilities but is also susceptible to mould growth. This work focuses on the hygrothermal performance of lime plaster in naturally ventilated residential spaces.

Is lime mortar more expensive than cement?

Yes, it is more expensive due to production cost of lime vs cement, basically down to volume of production. As more lime is produced, cost will reduce. However, as mortar takes up approximately 10% of brickwork, the cost difference is insignificant considering the benefits gained from using lime mortar.

Why is lime mortar better than cement?

Lime is protective

This helps reduce the risk of water ingress. Lime mortar also has a greater ability to transmit water vapour than cement-only mixes. This helps moisture to dissipate, thereby allowing the building to breathe and thus reducing the risk of frost damage.

What happens if you mix lime with cement?

Segregation is a major hazard of gauging lime mortars with cement. As the mortar sets, the cement colloid tends to migrate into the pores of the lime mortar as they form, clogging them and leading to a greatly reduced porosity.

What is the difference between Type S and Type N hydrated lime?

Type S contains 2 parts portland cement, 1 part hydrated lime and 9 parts sand. Type N is described as a general purpose mortar mix and can be used in above grade, exterior and interior load-bearing installations. It is also associated most commonly with soft stone masonry.

What happens if you don't use lime in mortar?

Brickwork mortars that are used without the addition of lime often present problems with water ingress in buildings.

Does lime cause rust?

No. Hydrated lime and portland cement are both alkaline in nature. The high pH environment normally protects the steel, preventing it from corroding.

Does lime damage metal?

Mixing calcium oxide with water produces a product known as hydrated lime or slaked lime used to disinfect barn surfaces. When dry, quicklime is not excessively corrosive to galvanized steel, but when combined with water, it creates calcium hydroxide, which is corrosive to galvanized steel and aluminum.

How corrosive is lime?

Lime is highly reactive and may be corrosive to certain materials. Spills should be cleaned up using protective equipment as described on the MSDS and with the utmost care. NOTE: Lime, being a commercial chemical, is available from numerous sources with various degrees of purity.

Does lime mortar rot wood?

Because lime and earth mortars are so porous, timber in contact with lime mortar is less prone to decay than when bedded in cement mortar. Historic houses did breathe and shed water when built.

How thick can you apply lime mortar?

On any surface one should be looking to apply a uniform thickness of lime render of about 9-12 mm (plasters being the top coat are applied much thinner, 4-7 mm). For the best results it is recommended to actually 'throw, cast or harl.

Does adding lime to mortar make it stronger?

Hydrated lime improves the strength of the mortar by several mechanisms: Carbonation - Hydrated lime reacts with carbon dioxide in the atmosphere to form limestone.

How long does lime plaster last?

Lime plaster is extremely durable. It can last for centuries, flexing with environmental changes as buildings move, regulating moisture and keeping the building dry over time. Many older houses or historical buildings will have lime plaster that's 100s of years old.

Does lime plaster smell?

You won't smell a thing when you apply it. Our materials take on the properties of lime stone making them hypo-allergenic, absorb carbon dioxide and expel excess humidity. The plasters lend a fresh and clean smell and feel to the rooms where they are applied.

What are the cons of lime plaster?

Disadvantages. Non-hydraulic lime plaster sets slowly and is quite caustic while wet, with a pH of 12. Plasterers must take care to protect themselves or use mild acids as vinegar or lemon juice to neutralize chemical burn. When the plaster is dry, the pH falls to about 8.6.

Why is my lime mortar crumbling?

Temperatures below 5C will slow the carbonation and hydraulic setting process and frost conditions will damage un-carbonated areas, resulting in feeble and crumbly finishes. If the mortar dries out too quickly, hydration and carbonation will be inhibited, drying shrinkage may occur and the mortar may become friable.

What can I use instead of lime mortar?

The lime in cement-lime plasters can be successfully replaced by the liquid mortar plasticisers DOMOLIT (dark coloured), or DOMOLIT-TR (transparent), which provide cement mortars with all the advantages of lime but without any of its disadvantages. Therefore: Increase bonding of the fresh mortar to the substrate.

Does lime mortar crack?

In carbonation of lime can only take place in the presence of water. It can years for a new plaster/render to reach its full strength. If plaster/render dries before sufficient carbonation has taken place then cracking can occur.

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