Multi-storey car parking facilities have to be designed to not only withstand challenging on-site conditions, but to do so while maintaining a clean and attractive environment that creates a great impression on each and every visitor.
This is especially true of the floor area within a car park, as among other things it will have to endure the movement of heavy vehicles, chemical attack from automotive oils and exposure to the elements.
In addition to these factors, it is important to consider whether the floor will require any additional properties to enhance the environment. This could include anti-slip additives, colours and signage, fire resistance and even specialist characteristics such as tyre squeal noise reduction.
The wide variety of flooring demands that need to be accounted for across a multi-storey facility has led many designers to utilise resin based deck coating systems. Resin solutions allow for the quick and easy installation of highly durable finishes that can be tailored to the various complexities of large parking structures.
When specifying the optimum flooring build up, it is important to bear in mind that there are key differences between the basement, intermediate and exposed decks.
Further, use of constructible BIM can help construction companies complete their affordable housing projects faster and more efficiently with reduced wastage that would help preserve their margins. The term “constructability” here defines the ease and efficiency with which structures can be built using BIM or Building Information Modeling. When developed and accurate enough, BIM lets the industry achieve efficiency with information-rich, as-built models and find possible problems before starting to work, using or wasting real materials. As-built models minimize costly surprises, RFI’s (requests for information) and opening way for more profitable projects.
Starting at the bottom, a key consideration for the lowest deck is the amount of moisture in the substrate or under the ground, as rising moisture vapour can lead to an early floor failure. If the basement slab is located close to a high water-table, then different moisture levels below and above the slab will result in moisture vapour transmission and will put pressure on the underside of the deck coating.
It is important to determine not only if rising moisture is present but also how much there is. To void moisture-related issues, a damp-proof membrane should be installed in order to prevent the ingress of water or other corrosive pollutants, such as chlorides or sulphates, into the basement’s interior as well as moisture penetration into and through the porous structure of the basement envelope.
The intermediate decks of multi-storey car parks are likely to face the most traffic abuse, as vehicles will consistently use these levels to enter and exit the building. This necessitates having a highly durable deck coating that will be able to retain a crack-free and attractive surface despite the intensive vehicle movement.
The problem of having to cope with very high traffic levels was exemplified recently at Mumbai’s Chhatrapati Shivaji International Airport when a second terminal was built. The vast new four-level terminal was designed to accommodate over 40 million passengers annually – which obviously required a new, very large multi-storey car park in order to deal with the significant increase in the airport’s users.
A nine-level parking structure was constructed (three levels underground and six above) with space for 5,500 parking bays divided into bays for cars, electric vehicles and scooters. The size of this facility made it one of India’s largest operational car parks.
In order to create a floor that would maintain a flat, crack-free and high performance surface in the face of thousands of daily users, 154,000 square metres of the polyurethane system Deckshield ID was applied across all of the facility’s intermediate decks and 7,500 square metres of Deckshield UV was installed on peripheral areas exposed to direct sunlight.
Intermediate decks will also have to cope with the most structural movement, as the cars will cause the entire building to move. Car parks are designed with expansive spans and minimal supporting columns to accommodate the maximum number of vehicles. When subject to a high volume of vehicles and cyclical traffic flow, this type of construction often leaves the structure susceptible to flexing and movement.
Crack-bridging polyurethane materials such as Deckshield can handle the unique structural movement of suspended slab and bridge cracks and therefore offer the necessary flexto move alongside the structure, preventing cracking that may develop in the concrete substrate from appearing on the surface as well as minimising any long-lasting damage to the structure itself.
Deck coating solutions such as Flowcrete India’s Deckshield range are the best options for such scenarios thanks to its full polyurethane formulation, which means that it is better able to withstand impacts, wear and traffic as well as the deflection within the slabs and decks of a car park that are caused by intense multi-flow traffic.This reliability stems from the combination of a polyurethane topcoat with a polyurethane primer, which makes it less brittle than systems that use an epoxy primer.
Exposed decks of multi-storey car parks are the most vulnerable part of the building.These areas have the most exposure to the elements and are therefore susceptible to high levels of thermal cycling, thermal movement and UV radiation as well asrain water and air moisture.
Thermal variations will cause the exposed deck’s substrate to expand and contract, imposing dynamic stresses that can crack the concrete substrate and expose the building to water ingress and chlorides that could result in long-term structural damage.
The most suitable material for exposed or external decks is a flexible, elastomeric and waterproof polyurethane deck coating.
These materials, whether applied at ground or elevated levels will offer the most robust protection to the external stresses caused by the elements.
Polyurethane based deck coatings exhibit a high level of UV resistance, which means that the vibrancy of the floor’s colour won’t deteriorate when subjected to intense and prolonged sunlight, a factor that can cause pigment shift and fading in unprotected finishes.
While different decks will have different challenges, there are many flooring attributes that are required on each level of a multi-storey car park.
Due to the presence of large quantities of petrol and the potential for car fires, it is critical to source materials that minimise the risk or severity of fires. To do this requires having an understanding of how the materials will behave during a fire and whether there is a likelihood that they will fail or hold back the fire for a prescribed period of time.
A car park can pose several fire risks, for example a car left in a long stay zone could be leaking fuel over the course of several days or even weeks – creating a significant hazard! To safeguard against the build up of dangerous substances, the floor area needs to be easily cleanable. This is achieved by creating a seamless and impervious surface that enables the cleaning regime to rapidly wash unwanted substances out of the area without having to worry about anything get stuck within gaps or cracks in the floor.
Flowcrete India’s Deckshield range is ideal for creating wide expanses of joint-free flooring and its fire resistance properties have been tested to the BS476 standard.
Alongside the structural requirements of a car park, the floor plays a role in making sure that the visitors have a safe and pleasant experience. To reduce the chance of painful slips and trips, which can be especially problematic in a car park due to automotive oils and greases, anti-slip aggregates can be incorporated into the finish to enhance traction underfoot. This property is especially critical in areas prone to excessive liquid, such as external decks that are open to the rain.
The surface profile of the floor can help to improve the car park’s environment in a number of other ways – even by making it a quieter and more peaceful space. Systems such as Deckshield ID have been tailored to drastically reduce the noise of tyre squeals created by cars turning in tight circles, making the facility a more relaxing place for visitors.
The colour and design of the floor finish is both a safety and an aesthetic consideration. Bright and easy to see footpaths will improve safety for pedestrians walking around the site and it will also make it easier for people on foot to navigate within what are often large and complex buildings.
Creating a floor that has clearly marked out bays and routes will also likewise make for a better driving experience, especially if the car park includes different zones that cater for various users or if there are designated bays for disabled visitors, families, motorbikes or electric cars.
This means that the design, cleanliness and aesthetics of the floor can go a long way to making sure that every visit starts on the right foot. Cleverly designing attractive colours, logos and patterns into the floor is a very effective way to improve a car park’s visual impact and is even an opportunity to convey the location’s interior design scheme and visual identity.
When undertaking the specification process for the deck coating material in a car park it is critical that all of the above points are carefully considered, as failing to sufficiently take any one of them into account can cause the floor finish to fail. To ensure that the chosen specification is up to the task at hand, the architects and designers leading the process should talk through all of these points with a supplier and applicator that are well versed in similar projects.
For further details
Flowcrete India Pvt Ltd
The Flooring Technology Center,
“Ganesh Towers” Door No.B-1,
1st floor, 1st Avenue, Ashok Nagar,
Chennai – 600 083. Tamilnadu, India.
Ph:+91 44 4017 6600
Fax +91 44 4202 9832
Email : firstname.lastname@example.org
Web : www.flowcrete.in