A 4mm “torch on” bitumen waterproofing product being applied by one of Indawo’s qualified teams.
Addressing a trustees’ meeting organised by the National Association of Managing Agents (NAMA members are responsible for the running of sectional title schemes) at the Cape Town International Convention Centre, Peter Jack, managing director of the multi-disciplinary contractor Indawo, said his company’s waterproofing teams are at this time regularly called out every time it rains.
“We are involved in a wide variety of activities, including painting, asbestos removal, safety and health management, structural repairs, general restoration and joint sealing. But in May, June, July and August we find that waterproofing repairs increase by some 300%,” he said.
“Most of these repair tasks should never have been necessary and could have been avoided. Most of the time the original installation and specification of the waterproofing was not handled by qualified people, or the maintenance has often not been carried out as specified by the manufacturer.
“If the original installation is done inefficiently or with inappropriate materials it will delaminate, crack or lose adhesion very quickly.”
Three main types of material are used in waterproofing. These are bitumen which is particularly suitable for flat roofs; acrylic compounds which are ideal for parapets and walls; and cementitious coatings which have many uses but are particularly known for their ability to give a good surface on walkways. Some of these coatings incorporate additional layers such as polyester cloth, but almost all of them are tried and tested and, if properly applied, will perform very well.
Once in place the waterproofing treatments have to be maintained every two to five years, depending on which material has been selected. If proper maintenance isn’t carried out, they will start to leak - and the leaks can be very serious indeed.
“If water penetrates into a steel reinforced concrete structure it will rapidly corrode the steel and cause spalling, or cracking of the structure, which will in time make the whole building completely unsound.
“In many cases, however, the water will not penetrate through to the steel but it will come up under painted surfaces. No matter how well these coatings have been applied and how good the original paints, these will eventually peel and flake as a result of the subsequent underlying moisture content not dealt with in the waterproofing specification or application.”
Jack said property owners can ensure that the original installation and the later maintenance of the waterproofing are done professionally if they use members of WARAC, the Waterproofing and Roofing Association Cape whose members all also belong to the Master Builders’ Association.
“WARAC members are all tried and tested waterproofing practitioners with skills not possessed by the average building contractor. In almost all cases they will submit full specifications as well as guaranteeing the work they do. Also, if there are any complaints against them, the WARAC committee will do all it can to put matters right. For all these reasons it definitely pays to use WARAC waterproofing contractors”
A large recent contract handled by Indawo was a seven storey block of flats, Lynwood Gardens in Kenilworth where, in addition to waterproofing, concrete spalling repairs of the type described above were carried out over a period of 24 weeks and V-joints inserted in the brickwork. Indawo is now busy with the parking deck for Ostende flats in Sea Point, which was originally waterproofed by the firm 24 years ago and now needs a new membrane.
“Modern waterproofing systems are sophisticated and efficient if applied and maintained correctly. Regrettably, there are still a great many inefficient, unqualified people doing this work,” said Jack.
Call Peter Jack on 021 941 5000 or email peter@indawo.biz.
