How to Waterproof Your Roof or Terrace During Construction

Terrace or Roof Waterproofing

The open terrace or the roof of your home is directly exposed to the heat of the sun and rains. The water entering inside the concrete of the slab reaches the reinforcement steel. The oxygen thus carried to the steel reacts to form oxides of iron that gives rust.

In this process, the reinforcement steel expands in volume and puts pressure in the surrounding concrete. This gives more room for cracks in the concrete.

As a result, more leakage and the cracks and leakages grow exponentially.

Once the leakage in the roof slab starts it becomes very difficult to repair. The problem becomes recurring and expenses of repairing become higher and higher.

Hence, it is most wise to go for a waterproofing treatment for your roof during the construction phase only. The cost of waterproofing at the construction stage is nominal. But ignoring this very important activity may be very expensive in future.

How to Waterproof Your Roof or Terrace During Construction

You may adopt a twofold step to waterproof your roof or terrace.

Integral Waterproofing

Membrane waterproofing

We will discuss the products Asian Paints Ltd offers here. We will find out what other companies offer in other blogs.

Integral Waterproofing - SmartCare Vitalia Neo from Asian Paints is a good option. 

This product may be used in a wet concrete mix.

The dosage of the red coloured liquid is mentioned in the pack. About 200 ml of the liquid chemical is to be added per 50 Kg bag of cement.

This is effective with M-sand (Manufactured sand) also.

Note that slight overdose of the chemical does not have any adverse effect.

For best result, you may follow the instructions of mixing mentioned on the pack.

The product comes in pack sizes of 200 ml, 1 ltr, 5 ltr, 10 ltr and 20 ltr.

While buying check that the pack is not older than 2 years from the date of manufacture.

SmartCare Vitalia Neo not only meets the requirement of IS 2645 for water permeability but is also compliant with IS 9103 for water reduction in concrete.

The product is lead-free and is water-based.

Some other benefits of SmartCare Vitalia Neo are

Imparts higher compressive strength 

Mixes easily with wet concrete/mortar

Resist corrosion of Reinforcement steel 

Now your slab concrete is in itself become a waterproof structure.

Membrane waterproofing - Smartcare Damp Proof from Asian Paints

Even after integral waterproofing, there might be certain points that may pose some chances of water seepage. To counter this and to have a long term benefit you should apply a membrane waterproofing.

Before applying you need to clean the surface thoroughly. This you can do by scrubbing the surface with a brush, grinder wheel, water jet. You should check that there is no loose particles and dust left.

Remember not to apply the coating in excessive heat or during rains. You need to ensure that the applied coating is not exposed to rain till 4 hours from the time of application.

You need to mix 3 parts of the liquid product with 1 part of clean water and stir well. The mixed liquid is to be applied on the cleaned surface with a roller or a brush in the same direction.

After the whole surface is covered in this manner with one coat let it dry for at least 4 hours.

After that, you can apply another coat of the liquid in the direction perpendicular to the previously applied direction. Let it dry for another 4 hours.

You can apply on the whole floor of the roof slab and extent till the top of the parapet. Ensure that no area is left out.

After the full application process, you will find a rubber-like soft layer been deposited. This is the waterproof membrane. This is an elastomeric resilient acrylic polymer and reinforced with polyester fibres for excellent elongation and tensile properties. Upon curing, it forms a thick, seamless, durable membrane.

Be careful that this membrane is not damaged by sharp objects. A protective coating of geotextiles, tile or simple cement mortar application may be applied so that the coating is not damaged.

Put your comments on how do you see waterproofing activity during the construction phase itself. Do you prefer to get it done during construction or you prefer to do it after some time has elapsed after construction.

Integral Waterproofing

Certain waterproofing chemicals are added to the concrete mix as an integral part of the concrete in minor quantity i.e. less than 3% by the weight of cement which reduces the permeability of the concrete and develops durability. This is known as integral waterproofing.

The manufacturers of such chemicals get the results authenticated by test procedures as described in IS 2645. A product certified by a competent authority of NABL approved testing laboratory may be relied upon.

While choosing an integral waterproofing compound you must check if the product passes IS 2645 test and guidelines and is certified.

These compounds may contain water-soluble Chlorides which is considered corrosive for concrete and reinforcement steel. Hence, you must check the contents of the product. 

The manufacturer is bound to mention chloride content which should be less than 2% by mass (Weight in common term) of the product.

Compressive Strength, initial and final setting times of the concrete should be within limits as mentioned in IS 2645. Note if there is any special caution mentioned by the manufacturer regarding these points.

How does Integral waterproofing compound work

The strength and permeability of the concrete, mortar plaster depend upon the Water – Cement ratio in the concrete during mixing and placing of concrete.

What the integral waterproofing compound does is, it helps to reduce the water requirement in the concrete mix this reducing the water-cement ratio.

When this compound is added it keeps the concrete flowable and workable even with less usage of water.

With less water, the concrete becomes less permeable to water and develops waterproofing quality.

The compound prevents surface cracks (which are developed due to drying shrinkage)

3 Top Integral Waterproofing solutions

There are many integral waterproofing compounds in the market now. One of the main reason for this is that consumers like you and me have understood the importance of waterproofing. We have become aware of the necessity of using an integral waterproofing compound more than ever before.

This is the most effective method since this is a type of preventive method. All other surface applications of water may fail if the subgrade (the concrete, mortar or plaster) is not of good quality.

The 3 most prominent integral waterproofing solutions are mentioned below with their brand names and manufacturers.

SmartCare Vitalia from Asian Paints

Conplast P211 from Fosroc

Sika CIM from Sika

I will discuss one by one to find out which one is most suitable for you.

SmartCare Vitalia Neo from Asian Paints

This product may be used in concrete, cement mortar in brickwork, internal and external cement plaster and even external putty.

You can make use of this compound in water retaining structures, bathrooms, drains, basements and any type of masonry surfaces.

This is effective with M-sand (Manufactured sand) also.

When used with external putty it improves the life of the paint in addition to giving a waterproof surface.

The dosage of the red coloured liquid is mentioned in the pack. About 200 ml of the liquid chemical is to be added per 50 Kg bag of cement.

Note that slight overdose of the chemical does not have any adverse effect.

For best result, you may follow the instructions of mixing on the pack.

The product comes in pack sizes of 200 ml, 1 ltr, 5 ltr, 10 ltr and 20 ltr.

While buying check that the pack is not older than 2 years from the date of manufacture.

SmartCare Vitalia Neo not only meets of the requirement of IS 2645 for water permeability but is also compliant with IS 9103 for water reduction in concrete.

The product is lead-free and is water-based.

It has some other benefits as 

Imparts higher compressive strength.

Mixes easily with wet concrete/mortar.

Resist corrosion of Reinforcement steel.

Conplast P211 from Fosroc

Conplast P211 may be used in concrete and mortar.

This may be used in the concrete and mortar for any place where water tightness is necessary. 

It is also very effective for inner and outer plaster of structures and in renovation works.

While buying check that the date of manufacturing is not more than a year.

The product dosage is not specified and needs a trial and error method at given site condition. The range of usage is 200 to 500 ml per 100 Kg of cement. The dosage may be arrived at while doing the mix design of the concrete.

This is a brown coloured liquid that easily disperses in water and is compatible with other Fosroc concrete chemicals. 

Conplast P211 comes in the pack sizes of 5 ltr, 10 ltr and 20 ltr.

It meets the requirement of IS 2645 for water permeability and is water-based.

Sika CIM from Sika

Sika CIM is a brown coloured fluid admixture which works with concrete and mortar.

In addition to preventing water permeability, it also provides good workability and helps to improve compressive strength.

It is suitable for concrete and mortar for rooftop slabs, damp proof course, Beams, Columns, Water tanks, Culverts, Tunnels, Sewerage works and any structure where watertight cement is required.

It is also effective for inner and outer plastering of structures and renovation works. 

It helps reduce plastering mortar due to rebound.

The chemical also helps in reducing post concrete shrinkage, hence preventing surface cracks.

It meets the requirement of IS 2645 for water permeability and is water-based.

It is available in pack sizes of 200g, 1kg, 5kg, 10kg, 20kg, 230kg.

While buying check the date of manufacturing. It should not be more than 1 year old.

The dosage is only 100g per 50 Kg of cement.

Remember to cure the concrete or plaster with water as per good construction practice. Curing is a must for the efficiency of both the concrete and the compound.

How to choose the one product for your use

By now you must have understood that each of the products is good and are from reputed brands which are leading the markets for decades now.

So how do you choose one. Just follow the simple steps below.

Find out which product is most easily available in your local market through 'locate a dealer' page.

With the cost-calculator find out who has the least cost for the total usage quantity for your project.

In the course of interaction with the dealers, you will come to know who is providing a better service.

For small usages, Asian PAints is the best option.

If you want to use it for large scale projects you may go for Sika or Fosroc.

Hope this gives you a clear idea on the integral waterproofing, the 3 Top Integral Waterproofing Solutions providers and how you can easily select a product for your use.

Please put in your feedback on the article.

Also, write if you have personally used any of the products. If you are going to any of these write about your experience.

Your notes will be very helpful for many other people and guide them.

You may check out my other article on surface waterproofing treatment.