By Candace Sofianos King | Photos by the ITC-SA
A healthy roof is a longstanding one, therefore the regular maintenance of a roof is imperative – not only for its longevity but also for safety and cost reasons. We investigate the best methods of roof inspection, repairs and maintenance.
While the importance of a roof structure as a component of a building and its functioning cannot be overstated, it is possibly one of the most neglected parts of a building. The roof is a structurally important and very costly component of a building – the average cost of a roof as a portion of the final building can easily exceed 25%.
The costs associated with repair or replacement of the same roof structure are even more than this due to the additional work required to establish structural integrity. Therefore, its imperative that a roof structure, on residential, commercial and industrial buildings, is regularly inspected for any anomalies and that remedial action is promptly and accordingly taken. A roof is a lifetime investment and should last just as long.
A roof withstands more from the elements than any other component of a building and the frequency of roof inspections and maintenance is dependent on the geographical location of the given building – if the structure is close to the sea or in similarly harsh conditions, it will need greater care than a structure inland, for example.
While some roof systems call for less intense maintenance than others, all roofing systems should be checked periodically and maintained accordingly, advises the Institute for Timber Construction South Africa (ITC-SA). Regarded as the professional body for the engineered timber construction sector, the ITC-SA provides design, manufacturing, erection, inspection and certification for compliance with inter alia SANS 10400 and SANS 10082, where engineering rational designs are applicable.
In the case of nail-plated timber roof structures, legislation stipulates that they should be designed, manufactured, erected and inspected by ITC-SA accredited members who have been awarded a Certificate of Competence. An A19 Certificate will be issued on compliance, which is required by the local authority before issuing an occupation certificate.
Best practise
In maintaining roof structures and industry standards, the ITC-SA offers CPD-accredited roof inspection courses. According to ITC-SA general manager Amanda Obbes, the Roof Inspection Training Course offered by the institute comprises an intensive theoretical and technical overview of timber roof structures.
“Students are exposed to basic terminology and timber structure design, framing and bracing, design consideration for light and heavily loaded timber roof structures, manufacturing, transportation and storage, and the various timber roof structures and types of buildings. Further to this, students get first-hand, up-close experience with the roof inspection process, as they venture onto two different construction sites which demonstrate both correct and incorrect roofing practices,” she explains.
Obbes continues, “The course is designed to enable: any technical person to conduct roof inspections with knowledge and insight; registered professionals to sign off roofs on their own, knowing they speak with authority; and individuals with experience in the roof construction industry to be sufficiently trained to inspect roofs under an accredited ITC-SA professional engineer.”
A certified roof inspector is defined as a practicing professional who will traditionally come from the built environment, must have prior experience in roof design and construction, and should preferably have a recognised qualification (NQF level 5) in the built environment.
Civil engineer Thea Smal highlights there are many players out there designing and manufacturing without any guidance or regulation. “The ITC-SA courses have taught me a great deal and have helped me to bridge the gap between what I learned from university and the practical application thereof. I believe that being associated with a professional body like the ITC-SA that helps to regulate the industry is very important,” notes Smal.
Making maintenance priority
Based on expert industry knowledge provided by MiTek Industries South Africa and International Truss Systems, the best preventative measure one can implement in the care of a roof structure is to conduct regular inspections to help identify and remedy problems as and when they occur – preventative maintenance is pivotal in saving money on a roof by providing a longer service life.
When it comes to the roof’s exterior, be sure to check for any cracked roof tiles, loose sheeting and loose roof screws. These may cause leaks, which have the potential to cause damage to the interior timber of the roof structure and prompt or accelerate wood rot. At the same time, look for open areas around newly installed antenna shafts and chimneys; while waterproofing should be installed to prevent any leaks, the condition of the waterproofing membranes must also be inspected regularly. Crumbling chimney mortar could also signal moisture penetration and will need to be reapplied.
Timber roof overhangs are most susceptible to the elements and should be maintained regularly to prevent fungal attack or rot from moisture. Loose fascia boards and leaking gutters are the most common cause of leaks onto roofing timber. On this note, be alert to any creeper plants growing onto the overhanging roof timbers. Keep all gutters free from debris and make sure the downpipes are draining properly by water testing them.
If the roof exterior is beginning to collect moss or algae, consider installing zinc or lead control strips to help control the problem. These strips form harmless zinc oxide when rainwater runs over them, in so doing, carrying with it a coating preventing further moss or algae growth.
Check all flashings, make sure they are not deteriorating and secure or replace any loose shingles. Trim back any overhanging tree branches and check any metal on the roof for signs of rust. Pay attention to all caulking and sealants, and scrape and remove any caulking that is weathered, cracked or damaged, and reapply. If the roof has gravel surfacing, be alert to any bare spots, otherwise, check for blisters in the roofing material.
Salt or dirt build-up can encourage rust on steel roofs, and moss and lichen growth on tiled roofs. Some manufacturers’ warranties advise regular washing, particularly in areas that don’t receive frequent rain. Frequent washing and inspection are advised to prevent salt and dirt build-up. Exposed timber trusses must be treated for exposure to the elements.
Cracked timber components in the roof structure are the first warning signs that something within the roof structure is deteriorating. Inspect all the components of the roof structure after new services, like plumbing, electrical and /or a fireplace, are installed. Check the interior of the roof for any leaks; these may be indicative of a leaking roof membrane.
If timber is beginning to show signs of rot, painting it will only worsen the situation. In this case, it is advisable to replace the affected timber. Painting and repainting should only be done on healthy timber surfaces. Be sure to adhere to the paint or treatment specifications concerning the application.
Additions, such as a cooking canopy that extracts smoke or steam from the kitchen, for example, are usually suspended from the roof trusses. In the case of additional loading, it is important to ensure that the load is spread across more than one truss. The load of the item should be established before installation and the truss design should be checked for any added loads. Use a professional to install items in roofs, such as additional ceilings, bulkheads and chimneys. Storage in roofs is not recommended unless the design of the roof specifically makes provision for this.
Legal compliance
As per the Construction Regulation 2014 Occupational Health and Safety Act of 1993, an owner of a structure must ensure that:
- Inspections of the structure are carried out periodically by a competent person in order to render the structure safe for continued use;
- That the inspections are carried out at least once every six months for the first two years and thereafter yearly;
- The structure is maintained in such a manner that it remains safe for continued use; and
- The records of the inspections and maintenance are kept and made available on request to an inspector.
