Roof Fastening Systems Keeping the roof above you

Roof Fastening Systems
"May the roof above you never fall in…" is a traditional Irish blessing. Holding up our roofs are the discrete roof fastener systems. Varsha Trehan takes a look at the options in the market.

Metal roofs, tiles or roofs doubling up as energy generators with their solar panels-all contribute towards the aesthetics and safety of all constructions around us. What make the roofs safe are those discrete yet strong roof fastening systems that have come a long way from bare bamboo and wooden lengths tied up with string.

Roof fastening systems are what foundations are to the building itself. Get it right and you are ready for maintenance free and secure structure. Modern structures, especially commercial buildings, are opting for modular design to enhance adaptability to meet modification according to client requirements.

metal roofing plywood deck

The vast range of roofing formats has brought with them a matching range of fastening options. They work for varying requirements arising from substructure, height adjustment, tilt angle, reinforcement and connections. More importantly, using appropriate fasteners support extending the life cycle of the roof is vital as they bear the stress. Weathering at the puncture points is often the most cited reason for roof damage, corrosion and leakages. Fasteners are selected for the specific purpose, performance and fastener frequency.

Metal roof solutions

Metal roofs, formed with sheets, tiles and shingles, are possibly the most popular option after concrete slabs in India. The environment friendly nature of these roofs is also a scoring point. Keeping these roofs in good health are several fastening systems.

Exposed fasteners systems: The choice of exposed fastener metal roofing panels is as wide as any other product option, which is always a good thing. These are convenient for walkways and canopies. Economy and long term wind resistance capabilities make these a popular choice. These are more efficient when backed by good design strengths. Additional fastening down, with larger number of points, is also possible.

metal roof solutions

Water proofing solutions for these panels involve rubber and polymer washers and caulking. The washers on the screws present wear and tear problems on the metal. As they not cater for weathering and temperature changes, the fixture points are affected over time. Manufactured from galvanized or stainless steel, they are more reliable when a metal cap covers the rubber seal.

Concealed fastener systems: Overcoming issues raised by long term use of exposed fasteners, concealed fastener panels rest on clips. Panel joints are also machine seamed closed for improved weather resistance. They have higher seams, definitive fastening and interlock designs. They are variously known as secret fix roof systems, raised seam or standing seam.

Most concealed fastener systems come as a package with roofing profiles. This resolves concerns of specific recommendations from the supplier. Aesthetics like color matching are also catered for. Polymeric and metal coatings on fasteners delay corrosion from these roofing accessories.

solar roof

Insulation fasteners: Insulation for sound damping and temperature regulation are essential in metal roofs. Metal liners and insulation are prefixed along the panel system to reduce puncture points and distribute weight. Insulation and protective materials are often used with metal roofs. This created a need for fasteners for metal roofs, thin layer module attachments and of course fasteners for PV flat roofs. Advanced products like insulated sandwich panels, require primary fasteners to hold the panels to the building. The secondary fasteners hold the panels together. Fasteners for special applications like sky lights or roof eaves work for strength and looks.

Available now are several innovative products like membrane roof anchors for safe working, stress panels and sophisticated fasteners like the self-drilling and self threading screws. Bolts and other aids are now specifically produced for keeping different materials like metal, insulation panels or polymer sheets together, while preserving the integrity of the structure.

Supporting green initiatives

As environmental care awareness grows, renewable energy projects are becoming an essential part of both new and existing construction. Solar panels are the new cladding and architectural element. Solar panels have developed into several forms to suit flat roofs, shingles, multiple roof tiles, facades and glazing. Besides energy generation and convenience the PVC membrane base protects and increases roof life.

On the structural side, fitting these panels increases considerable loads on the building roof. Add that to the wind forces and snow in extreme climes, fastening systems for solar roofs work for handling the stress with their secure hold.

Doing away with additional puncture points that are likely to damage existing sealing layers, solar module fastening systems are attached to the roof surface. Often designed as prefabricated assemblies, roof fastening for solar panels also save on installation time. The fastening systems inherently cater for load bearing, wind resistance and linear expansion issues created by the additional installation. Additional accessories like flashings cater for fatigue breaks in pipes and cables used in solar installations.

Sheets and tiles

Fiber glass shingles are for those looking for the traditional look. Most shingles are set on a base mat underlayment, usually asphalt impregnated felt. Underlayment has a double protection for the roof with water proofing and resin seepage. It prevents uneven setting of tiles. Fiber glass or asphalt shingles come with pre punched holes and need only roofing nails to be set in. With increased life span of the shingles, fastener quality has kept pace with materials that resist corrosion.

sheets tiles

Clay tiles are making a comeback as an ethnic design element. Layered on roof decks or sloping roofs, clay tiles are kept together with wire and clips over concrete and ballast. Tiles may be precast with holes to take galvanized or stainless steel nails. A better grip is provided by ring-shank over smooth shank nails. Both wire binding and nails are kept slightly loose to prevent tile cracks. Nailing and roof edge fitting keep roofs safe against wind blow-offs.

Standard roofing products have matched their panels and shingles to the most suitable fastener and anchoring systems. Cutting corners for short term benefits and a roof that delivers lifelong protection is certainly not the blend that works. In the long term, what brings back top return on investment is the ideal blend of product quality, design and skilled on ground installation work.

"May the roof above you never fall in And those gathered beneath it never fallout"

MGS Architecture May-June 2011