Tremco: Solutions For Problematic Leaking Podiums Latest Technological Advances

Sunny Surlaker, Marketing Manager, Tremco India Sunny Surlaker
Marketing Manager, Tremco India
India is seeing a spurt in urbanization. As we continue to build bigger, faster and taller, reinforced concrete is the choicest of materials to meet the needs of speed and durability. If we understand concrete simplistically, it consists of the aggregate skeleton that is strong, inert and relatively waterproof (except for a small bit of absorption). This aggregate skeleton is suspended in a matrix composed of the cementitious binder and water, what we commonly refer to as the paste. By virtue of the structure of the paste, it is this component of the concrete that is susceptible to porosity, capillarity and cracks. This makes concrete the hydrophilic, absorptive material that it is.

Therefore the concept of waterproofing too can be simplified as:
  1. Reducing Permeability / Porosity / Capillarity of the concrete itself with integral waterproofing additives
  2. Treatment of cracks and joints to prevent entry of water into the structure
  3. Draining / keeping water away from the porous concrete surface, using surface applied barriers.
New generation high-rise structures, especially in urban areas are being constructed with podiums present a unique challenge for waterproofing when compared to other parts of the building structure. Podium slabs are a special type of floor system that transfer loads from a steel, RCC or wood frame structure above the slab to walls and columns below.

Load bearing elements such as walls and columns of superstructure above the podium slab may not align with substructure load bearing elements below. Generally, this type of slab is constructed and placed at ground level parking with multiple levels of conventional residential construction above. The name is derived from the “podium” that separates the two occupancies [1]. Podiums are the areas which are otherwise known as common areas, mostly used for parking and other landscape / garden spaces.

The Challenges
Podiums are structures that may contain a combination of trafficable surfaces (cars, fire tenders, pedestrian / cycling pathways and other similar abrasive loads), garden / plantation areas and other general public use areas.

Waterproofing driven on podiums is the biggest challenge in a successful waterproofing program for a building. Normally the waterproofing systems used are highly elastomeric in nature, which makes them unsuitable in traffic conditions for abrasion resistance. Under traffic loads, the applied membranes often fail, leading to costly repairs.

The inherent problem here, is that the elastomeric waterproofing system is applied to the bare slab and covered with a floating wearable screed that acts both as protection to the waterproofing and a means to providing a slope. Casting this screed layer and the vacuum dewatering process used to enhance the abrasion resistance, causes the screed layer to crack. Further traffic movements cause the cracks to widen and eventually allow water ingress into the system, which further causes waterproofing problems below the podium slab. This damage mechanism is seen in driven-on podiums as well as in car park structures.

Further effects of this damage mechanism are that water along with dripping car fluids / oils, fuel and the abrasive loads, cause damage to the resin-based waterproofing system under the screed, allowing penetration of water through the podium slab and the areas below.

In roof gardens, the damage from the roots of growing plantations, damage the waterproofing system, allowing penetration of water through the podium slab and the areas below.

The Solution
Trafficable Podiums

New generation waterproofing systems for trafficable surfaces are designed to meet the criteria of ASTM C957 / C957M: Standard Specification for High-Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane With Integral Wearing Surface. These systems, based on tough polyurethanes, combine a highly elastomeric waterproof base coat, topped with an elastomeric but very tough wearing coat (with elongation of 120 – 140% and a tensile strength > 27 N/mm2). The interlaminar adhesion between the base coat and the wearing coat forms the basis of success in using these new generation trafficable waterproof coatings. In case of heavy vehicular traffic, the wearing coat can be enhanced using fine silica sand or alumina as a filler in the wearing course. Figures 1 and 2 show the application and finished surfaces for a heavy duty trafficable waterproof coating applied over a car park deck.

Application of a trafficable PU based waterproofing systemFigure 1: Application of a trafficable PU based waterproofing system

These combination trafficable systems are also designed for high UV resistance, resistance to petrol, diesel, lubricants as well as other aggressive salts and chemicals, and are also fire rated. New generation materials are environmentally friendly, low VOC systems, that are very easy to apply. The high crack-bridging ability (>1.5mm) and low abrasion (< 40 mg loss on 1000 cycles, by ASTM D4060) make it a material of choice to provide reliable waterproofing in the toughest conditions. The same systems can be further modified as hybrids of Polyurethane and Methyl Methacrylate (PUMA Systems) to form extreme wearing systems that can provide abrasion resistance and impact resistance, even for traffic by helicopters and airplanes.

Heavy Duty Trafficable Waterproofing System Applied to a Car Park DeckFigure 2: Heavy Duty Trafficable Waterproofing System Applied to a Car Park Deck

Expansion and Construction Joints
Expansion Joints and Construction joints are some of the most overlooked components of efficient podium waterproofing. Although the use of construction sealants is seeing some traction, often an incorrect sealant is selected for the application at hand. These joints and transitions account for about 1% of the constructed area, and yet 99% of water ingress into a structure occurs through these interfaces.

These interfaces need to be treated right the first time to ensure a leak-free structure. With this in mind, new generation sealants have been developed. To withstand the rigors of the Indian construction process, these sealants need to perform better in terms of:
  1. Excellent applicability and adhesion to different substrates
  2. Applicability to damp substrates
  3. Over paint-ability
  4. Very high Movement Accommodation Factors
  5. Quick curing to service.
The latest materials are high-performance, high-movement (-50 to +100%), single-component, low-VOC, UV-stable, non-sag hybrid polyurethane sealants. They are durable, flexible and offer excellent performance in moving joints and adhere tenaciously once fully cured. Joints (including expansion joints) up to 50 mm can be sealed only using this material. For joints > 50 mm width, the sealant can be supplemented by a mesh reinforced trafficable coating to provide a driven-over joint that will last long.

Planters and Terrace Gardens
The terrace garden slabs and planter areas also have unique requirements. The planters are often trough shaped, with multiple edges, which makes detailing of Root Resistant Membranes in these areas difficult. Root resistance and durability in submerged conditions is a key requirement.

In case of complicated substrate geometry, it becomes imperative to use a liquid applied membrane. This liquid applied membrane should have the capability to be installed on damp / green concrete, should have good mechanical properties and have resistance to being submerged in salt water. New Generation Moisture Triggered Hybrid PU Coatings provide the optimum combination of elongation, crack bridging, adhesion, chemical resistance and overall toughness. These cold-applied liquid membrane forming coatings can also be modified with a new generation additive to prevent root penetration through the membrane when used in planters or vegetated roofs. The additive functions without damaging the plant roots.

Detailing of Vegetated Planter / Slab using a coating with Anti-Root AdditiveFigure 3: Detailing of Vegetated Planter / Slab using a coating with Anti-Root Additive

However, terrace / podium garden waterproofing needs to be detailed properly to ensure success. One such detailing of a typical product is shown in the figure 3. New generation waterproofing systems for planter / garden areas are designed to meet the criteria of ASTM C836 / C836M: Standard Specifications for High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane for Use with Separate Wearing Course.

Conclusion
Today’s specifier or constructor has innumerable materials at his disposal, each claiming to be the best. Most of these materials are characterized by generic properties. These properties are suitable for Quality Control to produce batch certificates, but do not address the waterproofing system as a whole. The best waterproofing system is made of Good Base, Good Material and Good Application. Understanding the advantages and limitations of each of the materials used and a keen attention to detailing of the materials is the key to a successful waterproofing system.

That being said, modern materials such as moisture triggered polyurethane coatings, hybrid coatings, and new-age sealants are becoming easier to use, offer better durability, and are very robust for application under the harshest conditions of weather and mechanical resistance. Once the waterproofing job calls for exceptional performance, new generation materials do become imperative to provide a leak-free structure.

References:
  1. www.theconstructor.org
  2. Documentation and drawings from Tremco Inc.
NBM&CW April 2019
Fabric Reinforced Cementitious Matrix: Structural Strengthening Systems

Fabric Reinforced Cementitious Matrix: Structural Strengthening Systems

The need for structural strengthening in aging infrastructures is rapidly escalating across various sectors, encompassing buildings, industrial structures, bridges, dams, ports, and other important structures. This demand extends

Read more ...

Assess Build Chem: Long-Lasting Solutions for Basement Waterproofing

Assess Build Chem: Long-Lasting Solutions for Basement Waterproofing

Assess Build Chem provides effective and long-lasting protection for buildings with its innovative products and solutions for deep/large basement waterproofing. Basement waterproofing is a crucial aspect of building construction, especially in

Read more ...

Dam Rehabilitation With Cutoff Wall for Seepage Control

Dam Rehabilitation With Cutoff Wall for Seepage Control

As storm damage becomes more severe and has occurred more frequently in recent years, addressing the needs to repair essential infrastructure and dam rehabilitation is also becoming more common. However, deep foundation experts and others

Read more ...

JOGANI Reinforcement: Alkali Resistant ARACC Coated Waterproofing Mesh

JOGANI Reinforcement: Alkali Resistant ARACC Coated Waterproofing Mesh

Jogani Impex is considered an industry leader in providing international grade Alkali Resistant ARACC Coated waterproofing mesh, which enhances the waterproofing systems and solutions in all types of buildings and structures, while saving money

Read more ...

Assess Build Chem’s Deep & Large Basement Waterproofing Solutions

Assess Build Chem’s Deep & Large Basement Waterproofing Solutions

Assess Build Chem, a leading provider of construction chemicals, is ensuring long-term protection of buildings with its innovative waterproofing solutions that include a 5-step waterproofing method for deep and large basements. Sunny Surlaker, Head

Read more ...

Agrani: Waterproofing, Retrofitting, Civil Work & Interior Fit Outs

Agrani: Waterproofing, Retrofitting, Civil Work & Interior Fit Outs

By adhering to the highest industry standards, Agrani Group has gained a reputation for delivering solutions waterproofing, retrofitting, civil work & interior fit outs that surpass client expectations, avers Ramendra Bahadur Sinha

Read more ...

FAIRMATE's FAIRFLO CRYSTALLINE: Waterproofing Admixture for Concrete

FAIRMATE's FAIRFLO CRYSTALLINE: Waterproofing Admixture for Concrete

FAIRMATE is catering to the Speciality Construction Chemical Industry by manufacturing a complete range of construction chemicals like FAIRFLO CRYSTALLINE - Waterproofing Admixture for Concrete, along with cost-effective solutions and world-class

Read more ...

Nippon Paint India: Paints, Construction Chemicals & Waterproofing

Nippon Paint India: Paints, Construction Chemicals & Waterproofing

In line with its global vision, Nippon Paint India is expanding its portfolio beyond the paint and coatings product range; it will now offer products and solutions under the broad categories: Dry mix, Repair and Maintenance, Construction Chemicals, and

Read more ...

Alkali-Aggregate Reaction in Concrete Structures & Preventive Measures

Alkali-Aggregate Reaction in Concrete Structures & Preventive Measures

When the alkali of cement reacts with the reactive constituents of aggregates, the reaction is deleterious though very slow, and the distress is exhibited when the volume inside the concrete is increased due to the formation of alkali-silica gel, causing the

Read more ...

Retrofitting for buildings: Enhance structure lifespan & efficiency

Retrofitting for buildings: Enhance structure lifespan & efficiency

Despite understanding the potential of retrofitting and its distinct and far-reaching advantages in making existing buildings green and sustainable, retrofitting continues to be undertaken on a very limited scale; hence, it needs to be promoted and made mandatory

Read more ...

Cause of Distress of an Old Building Through Advanced Analysis

Cause of Distress of an Old Building Through Advanced Analysis

The technical service life of a reinforced concrete building is the time in service when structural safety is unacceptable due to either material degradation or exceeding the load carrying capacity, or both. In which case, the repair strategy may be adopted

Read more ...

Value Engineering with MCI®-2019 Water Repellent for Concrete Repair

Value Engineering with MCI®-2019 Water Repellent for Concrete Repair

True value engineering saves money without reducing service life or affecting the quality of construction or materials. Ideally, it adds value to the project. MCI®-2019 Water Repellent is one such value engineering solution that can extend

Read more ...

Agrani Milestone Use Carbon Fiber Laminates to Strengthen Slab

Agrani Milestone Use Carbon Fiber Laminates to Strengthen Slab

Ramendra Bahadur Sinha, Managing Director, Agrani Milestone, explains the remedial measures and challenges faced during slab strengthening of a deflected slab at IIT. NBCC India Limited undertook the strengthening of a deflected slab at a G+2 storey IIT building

Read more ...

Waterproofing Challenges & Remedial Measures in High Rise Buildings

Waterproofing Challenges & Remedial Measures in High Rise Buildings

High-rise buildings need special attention when it comes to waterproofing as the challenges inherent in them are peculiar in nature. Unfortunately, there is a lack of knowledge on the remedies and products available in the market as water- proofers continue to

Read more ...

Importance of Waterproofing Structures

Importance of Waterproofing Structures

The longevity of structures depends on how much resistance the building element will offer to water ingress. Water leakage not only reduces the durability but also hampers the serviceability or usability of the structure; hence, a good waterproofing system will

Read more ...

Terrace Waterproofing Solutions for Energy-Efficient Buildings

Terrace Waterproofing Solutions for Energy-Efficient Buildings

Terrace waterproofing is particularly important and is considered a priority as the roof is always exposed to harsh climatic conditions and weather changes. Rajeev Gupta, Business Head, ECMAS Construction Chemicals Pvt. Ltd. An effective waterproofing solution

Read more ...

Structural Rehabilitation of Reinforced Concrete Structures

Structural Rehabilitation of Reinforced Concrete Structures

Cement concrete is one of the most important construction materials and is practically basic to present-day developments. It is strong enough mechanically, yet vulnerable to deterioration. It thus gets damaged and even fails. This deterioration may be due to the weathering

Read more ...

Thermax - HDPE-SBS Waterproofing System for Basement Waterproofing

Thermax - HDPE-SBS Waterproofing System for Basement Waterproofing

Gradual shift in lifestyle has driven the idea of modern construction towards developing underground spaces and buried structures to bring efficiency in use of space. However, the improved efficiency comes with an increase in challenges like infiltration

Read more ...

Waterproofing in Hilly Areas with Sub-Zero Temperatures

Waterproofing in Hilly Areas with Sub-Zero Temperatures

Industry experts Kunjan Popat, General Secretary, Waterproofing Association of India; Ramendra Bahadur Sinha, Managing Director, Agrani Enterprises, and MS Sudish, Director, SIWIN Institute of Waterproofing and Insulation, share the challenges

Read more ...

Dow Sealants for Sustainable Infrastructure

Dow Sealants for Sustainable Infrastructure

Durability is a key requirement for modern infrastructure projects – highways and roads, bridges, airports and airfields, walkways and plazas, parking structures and stadiums. Miles of concrete must

Read more ...

To get latest updates on whatsapp, Save +91 93545 87773 and send us a 'Saved' message
Click Here to Subscribe to Our eNewsletter.