Why Buildings Smell: A Deep Dive Into Drainage Systems

In high-rise developments, modern drainage systems are essential for ensuring both the comfort and functionality of buildings. However, persistent odours— an often ignored issue—can arise when these systems are poorly designed or improperly installed as a result of improperly sealed water traps, leaking joints or unbalanced air pressure.

Understanding the root causes of these odours is particularly important in high-rise buildings, where faulty drainage can lead to costly consequences in the form of building repairs, reputational damage and even human health problems. More than just an inconvenience - these odours signal deeper issues such as patchwork installations, unsuitable materials, and substandard workmanship.

The Consequences of Patchwork Systems

When components are combined from different brands without proper planning or integration this creates a “patchwork” system. These systems significantly increase the risk of breakdowns and failures. Since each brand’s components have their own unique performance standards, patchwork systems lack the cohesion needed for seamless operation. Over time, this fragmented approach can result in degraded joints, failed seals, and consequently foul odours permeating our living, working and leisure spaces.

High-rise buildings face even greater challenges due to the complexity of their drainage systems. Mismatched parts often fail to handle the velocity and pressure of water required, resulting in further structural stress.

While mixing and matching components might initially seem cost-effective, it ultimately compromises system integrity. Each material reacts differently to pressure and thermal velocity, leading to misaligned joints and leaky parts.

A smarter solution is to opt for end-to-end solutions, created to meet the specific requirements of your building. Polypipe Middle East’s hybrid Terrain solutions eliminate the risks posed by patchwork systems by offering a complete, integrated solution designed to work in harmony.

The Importance of Proper (Solvent) Welds in High-Rises

Thermal movement is a phenomenon that occurs in drainage pipes, causing them to expand and contract in response to temperature changes.  Over time, it can place significant stress on the overall system. High quality welding, however, can play a critical role in maintaining joint integrity under these conditions.

Poor jointing installations can make the system particularly susceptible to the effects of thermal movement. Very often, the impact of thermal movement in drainage systems is overlooked, leading to leaks, smells and pipe bursts.

A common misconception is that solvent welding is outdated. In reality, however, they can provide increased strength and durability - when executed properly. Solvent welding creates seamless, air-tight seals on pipes to significantly reduce the risk of smells seeping out, even as the building expands and contracts due to thermal movement.

For high-rises, HDPE pipes that use electrofusion welding are also a highly suitable option. HDPE is a strong and flexible material, known for its resistance to corrosion and abrasion. This material and technique are especially effective at handling air pressure fluctuations and thermal movement by creating permanent, homogenous welded joints that prevents leaks and odours from emerging.

At Polypipe Middle East, our Terrain systems feature robust solvent welded and HDPE solutions, designed to deliver exceptional performance. Whether for mixed-use developments or towering high-rises, we understand that selecting the right, fit-for-purpose solutions—paired with precise, high-quality welding—makes all the difference.

The Role of Air Pressure in Drainage

In high-rise buildings, the terminal velocity of water in drainage pipes can reach speeds of 3 - 5 meters per second. Beyond this threshold, the speed stabilizes, however, the system must still endure immense pressure.

When water flows through pipes, it creates changes in the positive and negative air pressure. Positive pressure is when water moving through the pipe displaces air, creating a force that pushes gases back into the system. Negative pressure is when water rushing down a pipe creates suction. If air pressure is not properly managed, it can lead to water and odour leaks, as well as maintenance issues and disturbing sounds.

Our Terrain P.A.P.A.® (Positive Air Pressure Attenuator) and Terrain Pleura (air admittance valve) are innovative solutions designed for effective air pressure regulation.

Terrain P.A.P.A.® absorbs and dissipates sudden increases in positive air pressure caused by water surges. When a large volume of water flows down the system, Terrain P.A.P.A.® prevents the pressure from forcing air—and potentially foul odours—out of the system through weak points. It acts like a shock absorber to equalize air pressure surges and ensure the system remains balanced.

Terrain Pleura addresses negative air pressure. When suction occurs in the pipes, the valve automatically opens to let air into the system to prevent trap leaking. It stays closed during normal operation, which prevents gases and odours from escaping and when negative pressure is detected, the valve opens to equalize the system by admitting fresh air. This results in a quieter, odour-free building.

The benefits of integrating Terrain P.A.P.A.® and Pleura are ideal under the demands of a high-rise building. When used in conjunction with high-quality materials like solvent-welded HDPE pipes, they create reliable, long-lasting solutions that ensure a safe and comfortable building environments.

The True Cost of Poor Workmanship

Product selection, however, can only take you so far. Even the best products can fail when installation standards fall short. Many drainage issues arise from improper workmanship, such as poorly welded joints or misaligned fittings. This not only compromises the system’s performance but also erodes residents' trust in building infrastructure and management.

Lack of skilled workmanship is often one of the greatest challenges in drainage systems. Beyond training gaps, installers frequently face the added pressure of ambitious project expectations, making it difficult to deliver within tight deadlines and budgets.

To bridge the gaps, Polypipe Middle East provides hands-on training programs and certifications that empower installers to master essential skills, including solvent weld and HDPE welding. Recognizing the role of thermal movement, our Terrain solutions are equipped with fittings specifically designed to accommodate temperature shifts. Therefore, our training emphasizes the expertise required for proper bracket placement, ensuring system integrity and performance.

This commitment to quality ensures every Polypipe Middle East system, including Terrain, is installed to the highest standards, fostering pride among installers and delivering superior outcomes for all stakeholders.

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A Fresh Perspective on Drainage Solutions

The challenges of drainage in high-rise buildings are not merely technical inconveniences—they are critical issues impacting the health, safety, and comfort of occupants. From patchwork systems and deteriorating joints to poor workmanship and air pressure imbalances, these problems underscore the importance of selecting integrated, high-quality solutions.

Polypipe Middle East’s Terrain systems provide a future-proof approach, combining durable materials, advanced air pressure management, and expertly trained installation practices. By prioritizing proper planning and reliable execution, developers can ensure long-lasting performance, eliminate foul odours, and maintain building integrity.

Invest in smarter drainage systems today and create buildings that stand the test of time—safe, sustainable, and odour-free. Please reach out to our technical team for consultation:

Tel: +971 (0) 4 518 3000

Email: middleeast@polypipe.com