Water proofing is fundamental to building envelope design – get it wrong and the integrity of the entire building is at risk, with potentially catastrophic results. Here I discuss a couple of the most common problems with waterproofing basements and our best advice on developing a waterproofing strategy and design responsibility framework.
We often mention that it’s crucial for the project team to engage with us from the outset, to ensure that well proven and fully compatible systems are selected and properly installed. This is particularly the case when it comes to waterproofing basements, as it’s essential that overall ownership is taken of the, often complex, junctions between a basement and a podium level, for example.
A key element to consider when designing below ground waterproofing is how to provide continuity around foundation design and, in particular, piled foundations, which incorporate pile caps.
Waterproofing pile caps and sealing around piles can often be achieved easily with RIW Structure seal, which would be fixed to the inside of the shuttering and dressed around the piles. However, for more complex foundation designs and tight programs, other methods should be explored.
With this in mind we have developed a time saving alternative that negates the need to protect the pile caps themselves. This is to use our Crystalline powder in the form of dry shake application, across the top of the pile caps and around the reinforcement followed by lapping Structure seal, an external tanking membrane, onto this horizontally. Allowing for the uninterrupted construction of the foundations prior to the process of applying the waterproofing. In the construction industry, particularly within deep basement waterproofing, the pile cap interface is a crucial detail that can significantly impact the durability and safety of a structure. Traditional methods of wrapping pile caps with membranes have long been the norm. However, advancements in technology have introduced more efficient and reliable methods. Understanding the Pile Cap Interface
The pile cap interface is a critical point in construction where the pile cap meets the basement slab. Historically, this junction required meticulous wrapping of the pile caps with membranes to ensure waterproofing integrity. While effective, this method is labour-intensive and time consuming. At BPchem-BPT, we have pioneered new interfaces that eliminate the need for wrapping pile caps, offering a streamlined and efficient solution.
In a waterproofing scenario…
Our pre-applied waterproof membrane is designed to be installed underneath the basement slab. This system seamlessly connects with the pile cap, where BPchem a high performance coating, is applied to the top of the pile cap. This approach not only saves time, but also ensures a robust seal.
Waterproofing of raft foundation
Common issues and queries you can face while doing waterproofing of raft foundation
Waterproofing of immersed underground structures requires permanent dewatering during the execution phase and continues until the pressure caused by the weight of the concrete structure exceeds the hydrostatic pressure exerted by the water table.
The types of foundations designed for such structures is most of the time raft foundation with or without piles, or a combination of the raft and pile caps, depending on the bearing capacity of the soil. In such cases, the waterproofing is called tanking as it envelops completely the structure from the bottom to the water table level and preferably to the ground floor level. The waterproofing of the vertical part will start only when the full foundation raft/pile caps are cast.
Step by step solution
BPchem solution
Pile head waterproofing
The head of the pile should protrude by 20 cm higher than the blinding level. First, repair the pile head to provide a levelled and high strength capping. Then finish pile capping with an epoxy mortar.
Horizontal part of tanking under foundation
The surface of the blinding should be dry, smooth, plane and free from any obstacle that might puncture the waterproofing membrane.
To know more about the same, do visit our website www.bpchem.net or group corporate website www.bptonline.in or you can write to us at info@bptonline.in
