Roof Terraces

Roof terraces are designed to increase the amount of outdoor living space by converting underutilised roof areas. Roof terraces are essentially inverted roof systems positioned predominantly over an internal space with access directly from the building. It is possible to build a roof terrace on almost any flat roof. They can also be built on a pitched roof by retrofitting a flat area, however, this can be complex to achieve.

As with any outdoor living space, roof terraces can be timber decked or paved. If the roof space is a larger open area, it is not uncommon to see the application of exposed, slip resistant polymer resins. Some roof terraces feature planted areas and are effectively a combination of a roof terrace and a roof garden.

As is the case of roof garden build ups, the insulation layer is placed above the waterproofing and the vapour control layer that is installed on top of the roof deck. Many of the considerations for the design of green roofs also apply to roof terrace design.

What are the benefits of roof terraces?

• Additional amenity or recreational space
• Increased property value
• Planted over areas can improve the air quality
• Ready access for roof maintenance

What are the benefits of DensDeck® Roof Boards for roof terraces?

Roof terraces need to fulfil the traditional function of a roof, and in addition, need to cope with the extra loads of foot and vehicular traffic. Aside from being waterproof and having adequate drainage, they must provide fire protection and be thermally efficient. The final layer must also be able to withstand heavy winds.

The use of DensDeck® Roof Boards is recommended to protect the insulation layer from compression and the waterproofing membrane from penetration or other damage, especially if heavy foot or vehicular traffic is expected on the roof terrace. Cover and roof boards also improve the acoustic performance of a roof build up, improving occupant comfort.

A cover board enhances the puncture resistance of the roof system, offering a greater level of protection during the installation that continues throughout the lifespan of the roof terrace.

Key benefits of DensDeck® Roof Boards for roof terraces

• Fire protection
• Dimensional strength
• Acoustic performance
• Extended roof design life

technical data & downloads

DensDeck® Prime Roof Board
Thickness (mm)6.4 (¼ inch)12.7 (½ inch)15.9 (⅝ inch)
Length (mm)243824382438
Width (mm)1219


Datacentre construction has a unique set of demands on the building envelope performance. The roof system must be robust and waterproof. Any moisture penetrating through the building envelope could cause service disruption with considerable commercial impact or even damage the expensive equipment. Specification of fibreglass mat face gypsum cover boards is ideal for both new datacentre projects and roof renovations that seek fast project delivery times and exceptional building performance.

Heritage buildings

Conservation and refurbishment of roofs for heritage buildings demands attention to detail. They often use roof coverings made from traditional materials, making installation more time and labour intensive.

Heritage roofs may have areas that are difficult to access, posing a challenge when it comes to the installation and the performance of the roof system. Cover boards are specified to make roof refurbishment easier. They also help increase the building performance of traditional, heritage buildings.

Museums & libraries

Roofing systems for museums and libraries have the important function of protecting valuable collections and creating a safe, comfortable space for the public visiting the facilities. Museums and libraries often combine traditional heritage buildings and striking modern extensions.

This allows architects and designers to blend high performing heritage roof refurbishments with modern green, metal, solar panel roofs, roof terraces with parapet systems or a fusion of the various roof types. Cover boards are a crucial part of these roof build ups capable of enhancing their performance and extending their design life.


Airports, hangar and maintenance buildings, car parks and other buildings in the aviation sector present their own set of challenges. These projects have intensive schedules and once finished, the highest level of building performance is expected to keep passengers comfortable and safe.

The performance enhancing capabilities of fibreglass mat face gypsum cover boards are ideal for specification in the aviation sector.


The construction of biotech centres must overcome a very specific set of challenges. These buildings fall within the critical sector and the expectation is that their roofing systems must be very robust.

Specification of fibreglass mat facer gypsum core cover boards enhances the performance and longevity of roof systems for biotech centres. It can also target improvement in specific areas of building performance, as required by each project.

Send a project or specification enquiry

Start your project or simply get specification advice by dropping us a message.
One of our team will be in touch as soon as possible.