New Build Flat Roofing
We support the selection of flat roof systems based on the specific requirements of each new build project and its design criteria.
Early Project Engagement is Key
At Sika, we can provide technical input from the earliest project stages, including design brief and initial drawings, or once project criteria are defined. Information provided at these stages enables our technical team to prepare a specification that aligns with the project requirements, supported by relevant technical documentation.Our Area Technical Managers are available nationwide to provide guidance on New Build projects. We offer support throughout the process, including design review, technical calculations, specification preparation, and site inspections through to project completion.
Technical advice and specification support are also available for non-waterproofing elements, such as Sika’s green roof systems (where “green roof” refers to vegetated roofing) and photovoltaic panels when using the Sika Solar Mount (SSM) system. BIM objects and BREEAM documentation can be provided on request to support project requirements.
Flat Roof Design Considerations
Designing a new-build flat roof involves a range of technical factors. Sika can provide input during the specification process, based on project-specific criteria and applicable standards.
Key design considerations include:
- Fire classification (e.g., BRoofT4), subject to certified test data
- Roof area, rainfall intensity, and drainage strategy
- Wind uplift relative to building location and orientation
- U-value calculations and condensation risk analysis
- Structural use (e.g., load-bearing roof or balcony)
Performance data for waterproofing systems, including expected service life where supported by testing
Our Technical Services Team can assist with documentation and design inputs aligned to regulatory requirements and project goals. For further details, including BIM objects and BREEAM documentation, please contact us.
Sustainable Specification
Sika recognises the growing importance of environmental performance in roofing systems. In response to evolving specification requirements in new-build construction, our Global R&D teams continue to develop roofing membranes and systems with documented environmental credentials.
One example is Sarnafil® Advanced Technology, a hybrid membrane that holds Cradle-to-Cradle Silver Certification—currently the only single-ply membrane in the UK with this certification.
We offer a range of vegetated roof systems (“green roofs”) and waterproofing options. Our technical team can assist with specification based on project-specific criteria and available performance data.
If you require assistance with the design and specification of a roof area, our roofing team can provide technical input and guidance based on project-specific requirements. We offer a range of waterproofing systems, and our team can help identify options that align with the building’s needs and relevant standards. For more information, please contact us.
Sarnafil AT Green Roof Case Study
Flat Roof Solutions
Single-Ply Roofing Systems for New-Build Projects
Single-ply membranes are commonly specified for new-build applications where weight and load-bearing considerations are important. These systems can offer a low-profile solution and, depending on the product selected, may contribute to reduced installation time.
When correctly installed, single-ply membranes can provide a flat surface suitable for rooftop equipment and allow access for maintenance. Some systems are formulated without chlorides, fluorides, or plasticisers—please refer to the product datasheet for specific chemical composition and installation guidance.
Bituminous Roofing Systems for New-Build Projects
Bituminous roofing systems are commonly specified for new-build projects, particularly where design flexibility is required. These systems can be installed using self-adhesive sheets, hot-mopped asphalt, or cold-applied adhesives. The seams are typically heat-welded or bonded, providing a continuous waterproof layer when installed according to manufacturer guidance.
Bituminous membrane systems are available with published performance data for tensile strength, wind uplift, fire classification, and hail resistance—refer to the relevant product datasheet or certification for details. Service life and maintenance requirements should be confirmed and may vary depending on the specific system and installation conditions.
Liquid Waterproofing Systems for New-Build Projects
Liquid-applied waterproofing systems may be suitable for larger new-build applications, depending on project-specific criteria. These systems can be applied in a range of weather conditions (above 0°C), and some systems may achieve waterproof status within a short time frame—refer to the product datasheet for specific curing times.
Technical attributes of certain liquid applied membranes include elasticity and tensile strength, which may contribute to performance under movement or stress. Maintenance requirements vary by product and should be reviewed in the relevant technical documentation.
Green Roof Systems for New-Build Projects
As urban development continues to prioritize measurable environmental outcomes, Sika offers green roof systems that support biodiversity, stormwater attenuation, and energy generation.
These systems have been developed in alignment with Government policy objectives on energy resilience, carbon reduction, and sustainable urban drainage. The range includes blue, green, solar PV, and combined BioSolar systems, all designed to integrate with Sika’s roofing membranes and insulation products.