Securing a building’s outer defence

Waterproofing SBH Cotton Mills building was a colossal task in extreme weather conditions

THE HARSH Western Cape climate is known for its wet, rainy winters and extreme temperature fluctuations, and a building’s main defence against this is its roof.

Yet surprisingly little attention is paid to reinforcing the integrity of this vital outer defence system of a building.

However, one company t hat understands the importance of maintaining a strong roof structure is SBH Cotton Mills.

The barrel- shaped roof of its Epping building is one of the largest industrial roofs in the Western Cape. Waterproofer Indawo Painting and Waterproofing, commissioned to install a new waterproofing system on the roof, says it was not just the sheer magnitude of the project that was a challenge.

When commencing the project, Indawo discovered that previous contractors opted for inadequate waterproofing, resulting in several l ayers of dif f erent membranes, which could be one of the main causes of more than threats of water damage.

Peter Jäck, managing director of Indawo, says the SBH Cotton Mills building’s roof is one of the largest of its kind that required waterproofing. Several layers of waterproofing had to be lifted, exposing patch repairs rather than a safer and more comprehensive job.

“Not only do the layers compound the problem by masking any leaks, the enormous weight of layer upon layer of obsolete and ineffective waterproofing could be a contributing factor to the deterioration of the exterior integrity of the building.

“The vast surface area of the roof with its barrel- shaped structure tested the workforce to the limit when lifting the layers. High winds, extreme temperature fluctuations, interspersed with some late season rainfall, and a strict deadline to complete the project, meant the crew had to pull out all the stops to finish. On top of this, more than 72 truckloads of rubble had to be removed from the site.”

He says challenges that f ace crews on roofs in the Western Cape include high winds, relentless rain and extreme fluctuations in daytime temperatures, which cause discomfort for the workers and pose risks to their safety.

“All aspects of worker safety are taken seriously and they are monitored at all times while on the roof. The safety of workers and clients is of paramount importance, especially when it comes to the control of a large workforce for a project of this size. The whole process of waterproofing can be dangerous. The torch on is done at extreme heat using gas and, coupled with the manual process involved, requires special skill to avoid injury to the operator as well as other workers on site.

“We monitor the workers’ safety at all times to ensure all relevant health and safety guidelines and procedures are adhered to.”

To secure the SBH building’s roof and prevent water ingress, Indawo laid a technologically advanced torch-on waterproofing system. A double-layer system was installed in the gutters and between the barrel structures, and a three-layer system on the balance of the roof.

The final covering is a single layer mineral-surfaced heat-fused membrane, the latest in this technology from Italy, which offers maximum protection. Skylights on the roof had to be repaired and waterproofed and sufficient sloping run- offs for rainwater maintained between the barrel structures.

Cal l 0 2 1 9 4 1 5 0 0 0 o r e mail info@indawo.biz for further information.

VAST: The barrel-shaped roof at SBH Cotton Mills in Epping is one of the largest industrial roofs in the Western Cape.