Important Function of Expanded Polystyrene Insulation Boards When Using Cavity Wall Insulation



EPS is one of the most preferred insulation materials in the UAE construction industry. This is primarily due to the highest insulating capacity/dollar offered by the Expanded Polystyrene Insulation Boards. It lowers the total cost of cavity wall insulation by 25%-50% and improves the insulating capacity.

Owing to its high thermal efficiency, lightweight, shock absorption, durability, and moisture resistance characteristics, EPS drives the construction market in the UAE. The UAE has witnessed expansion in its construction projects after hosting the world expo in 2020. This further triggered the growth of the EPS market in the UAE.

Some of the major construction projects in the UAE include Al Habtoor City, Marsa Al Arab, Bvlgari Resort Hotel and Marina Village, Al Seef, Dubai Creek Harbour, and Jewel of the Creek. This increase in construction activities has augmented the demand for EPS in the country. Moreover, the rapidly booming investments in the UAE construction sector are further expected to trigger the EPS demand in the country.


Cavity Wall Insulation With Expanded Polystyrene Insulation Boards

The sheathing is one of the most widely used EPS insulation applications in both commercial and residential construction. It develops an envelope around the constructed structure covering the cavity walls. This helps in improved moisture penetration and heat transfer.

The energy crisis in the 1970s caused people to look for cost and energy-efficient sheathing materials. EPS foam boards soon became the industry standard in UAE due to their high insulation performance, ease of installation, and versatility.

The sheathing is usually used as an exterior cavity wall insulation both above and below grade. The different densities of the EPS board help to meet the R-value requirements for energy codes of local buildings in the UAE. Moreover, using a reflective aluminium facer for your EPS sheathing board will increase the cavity wall’s resistance to heat absorption.

EPS sheathing is compatible with masonry, steel, and wood framing. The EPS boards are vertically installed over the stud’s exterior sides. The board can be glued with spot adhesive or fastened with screws, staples, or nails. However, you must refrain from adhesives containing petroleum-based solvents as they will dissolve the expanded polystyrene on contact.

One of the most essential functions of an EPS sheathing is to control moisture in the cavity wall by serving as a vapour retarder. A perforated EPS sheathing foil increases breathability in the case of above-grade constructions. This helps to eliminate the buildup of condensation between the exterior and interior of a structure.

Besides performing as a vapour retarder, EPS facers also help to improve the board’s surface adhesion for adhesives and taping. Additionally, the performance of your cavity wall will not deteriorate when used with EPS boards. Fungus, moisture, water, rot, and bacteria do not reduce the insulating performance of EPS boards.


Expanded Polystyrene Insulation Boards VS Other Insulating Materials

Most of the cavity wall insulation in the UAE is completely safe — but it depends on the workmanship quality and material used. Modern cavity wall insulation methods using an EPS Insulation Board pose no threat to the lives of those living in that home. Using the right insulating material is essential as it prevents poor air quality and dampness in your homes.

Urea Formaldehyde Foam Insulation

From the 1970s to the 1990s, most people tried to quickly insulate their homes at the cheapest cost. This started the trend of spraying formaldehyde foam insulation into cavity walls. Some of the major problems caused by such formaldehyde foam insulation include —

  • When the formaldehyde foam shrinks, it leaves air gaps in the cavity walls which later triggers cold bridging.
  • When the formaldehyde foam insulation decomposes, it produces chemical fumes causing respiratory problems in people.
  • It may cause the air to become potentially dangerous to your health.

Blown Fiber Insulation

To overcome the issues of urea-formaldehyde foam insulation, many households shifted to blown fiber insulation. The fiber is usually injected into your cavity wall where it settles over time and compacts. Blown Fiber insulation is generally safe when it is completely sealed within your cavity walls. However, if the blown fiber escapes through any gap in the cavity wall it can be a nightmare to some households.

Blown fiber insulation isn’t considered hazardous — but it can severely irritate your skin and eyes if it escapes. Moreover, such insulation is not suited to all cavity wall constructions.

Often rainwater escapes into the cavity and saturates the blown fiber. This rainwater can then run down to the internal walls and create the ideal environment for dampness. Blown fiber insulation will fail in such cases as wet fiber serves no purpose as an insulator. Moreover, mold and dampness can cause serious health implications.

Expanded Polystyrene Insulation Boards

To do away with the limitations of cavity wall insulation, EPS was introduced. The EPS Foam Board and expanded polystyrene beads have paved the way for modern cavity wall insulation. These EPS boards will remain effective over decades and provide the ideal insulating performance. Some of the important functions served by EPS when using cavity wall insulation include —

  • These are completely waterproof and free of health implications.
  • It prevents cold spots, dampness, mold, and damp smells from occurring.
  • It protects your cavity wall from excessive condensation or leaking insulation.
  • The closed-cell structure of EPS consists of 98% air which acts as a poor heat conductor. This provides the EPS Foam Board with unrivaled thermal insulation properties.

Additionally, using a bonding agent to glue the beads together offers the best insulation. This will allow the EPS to perfectly settle inside your cavity wall.

Summing Up

The use of an EPS Insulation Board for cavity wall insulation has steadily increased over the last decade. It primarily performs as a vapor retarder to prevent damp and moisture in cavity walls. Moreover, the high insulation efficiency, low maintenance, water resistance, and varying densities make EPS boards the ideal insulating material. Moreover, you can fix a variety of finishes and sidings through the exterior EPS sheathing to construct an aesthetically pleasing home or building.