March 2020

By Martin Bidewell, Head of Technical for Sika Roofing

When it comes to specification, paying close attention to seemingly small details will go a long way to ensuring a roof remains watertight and problem-free during its lifetime. Design, technical support, surveying and contract management all have a part to play in successful roof installation. Such details are crucial to ensuring a building’s uppermost, protective layer remains as impervious to the elements as the day it was installed.

As with most, if not all roofing projects selecting an appropriate waterproofing system is crucial in applications involving a plethora of plant materials. PV panels, air conditioning units, rooflights and the like require regular maintenance. Therefore, great care should be given to the type of protection installed if the roof is to perform as required and remain watertight. This is also true of other details such as junctions and upstands, which if not properly accounted for, can compromise a roofs’ watertight performance.

Ready expertise
The specification of a single-ply system can help alleviate risk when it comes to roof installation. This outcome is easiest and best achieved in conjunction with companies such as Sika, which works closely with customers on the selection of a suitable system for a wide range of roofing applications. Engaging with a specialist roof manufacturer at the start of the roof specification process minimises the risk of future problems. Oversights in relation to insulation or rainwater outlets, for example, could lead to water-ponding and premature wear and tear.

Sika-Trocal’s single-ply membrane range includes:

Sika-Trocal® SGK: a reinforced PVC waterproof membrane with a polyester fleece backing for use in adhered applications. As well as supplying high-tensile strength, Sika-Trocal® SGK provides outstanding weathering and excellent flexibility in cold temperatures, which along with its easy-fit benefits makes it an ideal membrane for exposed roofs.

Sika-Trocal® Type ‘S’: this exposed, mechanically fastened PVC homogeneous membrane is the most widely specified roof option. Suitable for new-build and refurbishment applications, Type ‘S’ is the most rapid and economic system to install. It uses a Sika-Trocal Laminated Metal Disc and thermally broken fastener to secure both the membrane and insulation, rather than a separate fastening system utilised by many other single-ply systems.

Sika-Trocal® SGmA: A homogenous sheet with a layer of random glass fibres designed to eliminate shrinkage; this product is intended solely as a covered roof membrane in protected roof applications and can usually be restrained against wind uplift forces by the dead weight of ballast.

Assurance scheme
Once the single-ply membrane and installation method has been specified, the relationship between the manufacturer and the roofing contractor becomes absolutely crucial. Therefore, Sika-Trocal operates a Licensed Contractor scheme that assures the client their roofing system will be installed by a high quality and trusted applicator, carefully trained by the Sika Roofing Applications at our Single Ply Training Centre in Welwyn Garden City.

Utilising the expertise of a manufacturer and producing highly-detailed plans before the project begins, assures a roof’s waterproofing project is completed correctly the first time, every time. Whatever the installation, specifiers, contractors and their clients must turn to manufacturers and designers such as Sika to ensure a quality specification that meets the very highest standards. It will also minimise potential for a project falling foul of the unseen devil in the detail.

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