Water is counted as the biggest treasure. It is a necessity for every life existing on the earth whether they are humans, animals, birds, trees, etc. However, water, in any form – liquid or vapour, is also an enemy to all the constructions materials like concrete, stone or masonry. This is because the groundwater, surface water and rain caused damage to the houses.
To save the integrity of the house and keeping its functionality intact, it is a must to waterproof the house. There are certain areas of the house having a high probability of water intrusions like bathroom, basement, kitchen, balconies, swimming pool, the exterior walls, and the roof. All of these areas need special attention.
Waterproofing will help in making the structure water-resistant and will act as a barrier over these surfaces that will prevent penetration of water. But the type of waterproofing also plays a key role in halting the water penetration. Failure of a single component can destroy the complete waterproof system. Let us go through some basic information about the waterproofing.
What is Hydrostatic Pressure?
A pressure that has been exerted by a fluid at symmetry at a given point inside the fluid through the gravity force is something we refer to as Hydrostatic Pressure.
Positive and Negative Side Waterproofing
A positive side waterproofing is a technique where the coating on the concrete wall is done on the same side of water pressure whereas a negative side waterproofing is a method where the coating is applied on the concrete floor on the opposite side of the water pressure. Cementitious and Flexible Cementitous Waterproofing apply both the positive and negative side methods.
Must-have features of any Waterproofing system
A waterproof system needs to be completely perfect as a little defect ruins the whole system. However, there are some of the key attributes that any waterproof system should possess:
- It should be resistant to moisture infiltration which means it should be waterproofed and damp-proofed
- Effective and durable
- It should be able to fight when exposed to any environmental conditions, especially rain and waterheads.
- Robust and long-lasting
- Flexible and breathable
- Positive/Negative which aid in reducing the permeability of the concrete
- Resistant to chemicals
- Polymer modified the cementitious coating
- Building cracks
Available Waterproofing Methods
There are several methods of waterproofing available. Below mentioned is a list of all those:
- Bituminous Membrane
- Polyurethane Liquid Membrane
- Liquid Waterproofing Membrane
- Bituminous Coating
- Cementitious Waterproofing
All the above-stated methods are designed in a manner that the application differs but the purpose remains the same. We will go through the Cementitous Waterproofing Method in this article:
Cementitious Waterproofing Method
This is the easiest method of waterproofing any structure among all the methods. Being easy does not decline its effectiveness. They can protect almost any structure which is constantly exposed to wetting or low hydrostatic pressure.
Areas Cementitious Waterproofing is ideal
As said, they can protect any part of the structure from being wet, but there are some areas where their performance is unmatchable. Such areas are wet rooms, water tanks, terrace, bathrooms, walls of the basement and swimming pool.
Types of Cementitious System
Let us go through several types of cementitious systems:
- Metallic Systems
These minerals contain a blend of cement and sand along with finely graded iron fillings. When a slurry is made by mixing the water with this, the iron fillings get oxidize where the water act as a permitting agent
- Chemical additive systems
These are a mixture of organic or inorganic chemicals, sand, and cement. When this is applied to masonry or concrete substrates, they yield a watertight substrate by chemical action
- Capillary or Crystalline Systems
A combination of cement and sand along with proprietary chemical derivatives in liquid or dry form is what falls into this area. Their application is through brush, spray or trowel.
- Acrylic Modified systems
An acrylic emulsion is added to the basic cement and sand mixture. When this is applied, waterproofing properties and characteristics are automatically added to the in-place materials.
Process of applying Cementitious Waterproofing Method
- Before waterproofing any surface, it is a must to clean the damaged surface and make it free from any dirt, debris, any form of dispersing agents and other such materials. It is good if the concrete surfaces are acid-etched and sandblasted as this will help in proper bonding to a surface.
- Firstly, one should check for any cracks, tie holes or honeycombs. If any of this presence is noticed, it must be filled with an initial application of the cementitious system. Thereafter, all the wall intersections like wall-to-wall intersection, wall-to-floor joints should be formed with a 1-inch cut-out in a manner that a cove is formed. This cove should be then filled with cementitious material. Utmost care should be taken in this detail as no thermal or structural movement is permitted which makes it very critical.
- The formation of this cove will prevent any water intrusion in the weal areas that are prone to develop crack easily. However, in case the cove is not formed properly, a cant of materials made using a dry mix of cementitious materials can be placed at the intersections.
- When using this method, there is no need to prime the substrate before applying. However, it calls out for wetting the concrete using water which is un-avoidable.
- They are available in several packaging ranges. Either they can be blended with sand and cement in a bucket or irons and chemicals to be used must be kept in separate containers, which can then be added to the sand and cement mixture. It is essential to use clean water in the entire process and also, the mixing of the materials should be done as per the guidelines of the manufacturer.
- Once the basic preparatory task is completed, the cementitious system is applied and it is mostly two coats. The coat of proprietary materials is the first coat. Thereafter, the chemicals and metallic materials are coated present within the sand and cement mixture. Generally, two coats are more than enough. However, if it seems that a third coat will be useful in protecting the surface, then it should be applied too. This third coat comprises of cement and sand for enhancing the texture and shielding the exposed surfaces.
- A reinforcing mesh embedded with the initial coat is required by the acrylic systems. For applying the coating, one makes use of trowel, spray or brush. The thickness relies on the coating contents – sand and cement.
- Generally, it is ideal to make use of the dry-shake application where, the concrete is integral with the waterproofing area; hence, few of the applications are dry-broadcasted over just made floors of concrete. Once the powder is put on the concrete floor, power troweling is done to finish the process and for the dispersion of the activated chemicals. Being quite difficult to monitor and control, this method is not recommended for very critical areas that are subject to water head.
- To protect the susceptible areas, some finishing is done over the membrane and this finishing can be of anything like carpet, tile, topping or any such finish. A wet treatment of 24 to 48 hours is must for this cementitious waterproofing application.
- The cementitious method is a very rigid or semi-flexible type of waterproofing method. Mostly being done in all internal areas, it is not exposed to sunlight and weathering. Hence, it does not go through the contract and expansion method.
Advantages of Cementitious Waterproofing Method
- Possess excellent resistance to water. Even when the surface is permanently exposed to water like humid rooms and damps such as bathrooms, the cementitious method will waterproof the surface
- Tolerates any long-term weather condition, brilliantly fights them
- They are puncture proof because of the hard-wearing cement
- Have a good power to resist any scratches
- The load-bearing capacity is very high
- The solution is affordable
The disadvantage of Cementitous Waterproofing Method
- Though highly effective, it becomes difficult to hold up cracks. There are situations where leaks are observed from the wall. Now, this method does not hold up in the face of any cracks and are damaged severely in case leakage disappears.
It is very easy to use the cementitious slurries and these are non-toxic. They provide a fully bound, mono-lithic, joint-free zone which makes it quite easy to be applied to any area having a complex shape.
As compared to the bitumen-based minerals, the cement slurries possess physical properties which are very less dependent on the temperature. They can be applied to any wet or damp mineral surfaces
- Though the simple cement-based method is used for protecting the surface against water, sometimes it becomes quite difficult to prevent the area against water under very high hydrostatic pressure. To overcome the impermeability of the poor water and poor adhesion, we can add polymer.
- If we want to be free from the wet curing of the slurry, one can make use of additives such as rheological, thickeners, water-retaining agents that are blended with a polymeric binder. This will ensure the brilliant working of the application.
- When talking about polymer binder, the dispersible polymer powders that are obtained from ethylene and vinyl acetate, are in general plasticizer-free polymers and thermoplastic.
Types of Cementitious Waterproofing Membranes/Slurries
In the market, there are many types of cementitious waterproofing slurries or membranes available which are listed below:
Rigid Waterproofing Slurries
- The rigid waterproofing mineral slurries are pre-packed, polymer-altered and dry-mix mortars which, before getting applied as a slurry using a roller, brush airless spraying are gauged with water. If in case, less water is used, one makes use of a trowel.
- Only and only on the stable, sound and sturdy mineral substrates, where there is no danger of any crack formation, this rigid waterproofing slurries can be used. When making use of the dry mix mortar, the most ideal polymer is dispersible polymer powder that provides a hydrophobic effect.
Flexible Cementitious Waterproofing Membranes – Dual Component
- When one wants to bridge all the cracks present in the substrate, the flexible cementitious membrane is very ideal. The method’s malleability relies heavily on polymer/cement ratio and very less on the polymer. Also, the malleability depends on environmental situations to which the surface is open to.
- All the surfaces facing vibration, stress, shrinkage, crack development and those that have difficulties in sticking like steel, wood, gypsum and aerated blocks.
- As they possess polymer content in a huge amount, they are immune to chemicals like carbon dioxide, sulfate ions, chloride ions, etc and also possess less diffusion coefficient.
Flexible Cementitious Waterproofing Membranes – Single Component
- There are some limitations attached with Dual component system, which is must to know. If one does not have sufficient knowledge, experience and exposure, especially the workers lacking the knowledge of appropriate liquid component dosage, this might cause blending errors. Many make use of the wrong proportions to save money in short duration. If in case, the proportion of liquid dosage is very low, it will affect the waterproofing process badly where the membrane will not be resistant to water when they are made open to hydrostatic pressure and will fail the entire system.
- Not yet ending, there is some other problem with the dual system – risk handling. The expense and logistics associated with this are too much time-consuming.
- Hence, to get rid of all these problems, the single component is being used widely. Over here, the dispersible polymer powders are being made use of which possess low water absorption, high water resistance for formulating the one component flexible cementitious waterproofing slurry.
Structures applying Cementitious Waterproofing
By now, you might be very clear that cementitious waterproofing is used widely in several different areas. Some of those are mentioned below:
- Railway plus Subway systems
- Swimming Pools
- Portable water facilities
- Foundation wall waterproofing
- Elevator shafts
- Parking garages and Lots
- Marine structure (Cargo Ports and Docks) protection
- Secondary containment modules
- Industrial waste-water tanks
- Water and Sewage treatment plants
- Municipal water storage tanks
Hence, cementitious waterproofing method is widely used in various areas and if you are looking forward to waterproof your house, we are the best known waterproofing company in Toronto. We hope, we have cleared you about what this cementitious waterproofing is all about.